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The dollar soars as US inflation rises

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Written by:
Myrsini Giannouli

14 September 2022
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Important calendar events

  • JPY: Core Machinery Orders, Revised Industrial Production
  • GBP: CPI and Core CPI, PPI Input and Output, RPI, HPI
  • USD: PPI and Core PPI

The dollar spiked on Tuesday after the release of higher-than-expected US inflation data and the dollar index rose above 109.6. US Treasury yields also rose, with the US 10-year bond yielding above 3.4%.

US CPI data released on Tuesday exceeded expectations, propelling the dollar upwards. US inflation forecasts indicated that headline inflation was going to decline, due to decreased fuel costs. Monthly CPI was projected to decrease by 0.1%. Instead, CPI increased by 0.1% in August. Annual CPI through August increased by 8.3%, which presents an improvement compared to July’s 8.5% and June’s peak of 9.1%. US inflation, however, was expected to decelerate at a faster pace this month due to a slowdown in energy costs. The monthly core CPI in August increased by 0.6% against the 0.3% forecasted.

The dollar went up after the release of the US inflation data, as the Fed is likely to maintain a hawkish stance this month to combat persistently high inflation rates.

Fed rhetoric propelled the dollar to 20-year highs in the past couple of weeks amidst mounting expectations of a steep Fed rate hike in September. Markets are currently wavering between a 50-bp and a 75-bp Fed rate hike in September, with odds favoring a 75-bp rate hike after Tuesday’s inflation data.

Inflation PPI data are due on Wednesday and may affect the dollar significantly, especially after the release of the CPI indicators, as US inflation levels are expected to play a crucial role in deciding this month’s Fed rate hike.

The Euro plummeted on Tuesday, on weak Eurozone economic data. At the same time, the dollar soared on higher-than-expected US inflation data and the EUR/USD rate fell back to the parity level. Currently, the currency rate is testing support at the strong psychological parity level of 1.000. If the EUR/USD declines further, it may find support at the 0.845 level representing the 2002 low. If the currency pair goes up, it may encounter resistance at 1.019 and further up at 1.036.

On Tuesday, the German ZEW Economic Sentiment Index decreased to -61.9 from -55.3 in August, while Eurozone ZEW Economic Sentiment fell to 60.70 in September from -54.90 in August. EU economic outlook remains poor, limiting the ECB’s ability to hike interest rates and putting pressure on the Euro.

In an unprecedented move last week, the ECB raised its benchmark interest rate by 75 basis points, hiking its deposit rate to 0.75% from zero. The ECB will start paying interest on government deposits in a bid to keep that cash from flooding an already replete market facing a squeeze in bonds.

Markets are now poised for the ECB’s next move. On Monday, hawkish ECB rhetoric propped up the Euro. Bundesbank President Joachim Nagel stated over the weekend that further steps are required to bring Eurozone inflation under control, pointing at further rate hikes this year.

Europe however, is facing an energy crisis, which seems to be escalating, driven by the EU’s dependency on Russian energy. High energy costs in the Eurozone are driving the Euro down, while inflationary pressures mount.

Eurozone headline CPI jumped to 9.1% on an annual basis in August, the highest on record. Inflation in the EU is expected to rise even further in the following months, possibly reaching double digits, driven by the high cost of energy in the Eurozone. Increased price pressures are forcing the ECB to take swift action to tackle inflation. Rising Eurozone inflation is expected to figure largely in determining the future ECB monetary policy.

EURUSD 1hr chart

The Sterling dipped again on Tuesday, after touching its lowest level since 1984 last week. The GBP/USD plummeted to the 1.151 level after the release of the US inflation data. If the GBP/USD rate goes up, it may encounter resistance near the 1.190 level, while if it declines, support may be found near 1.140, representing the 2020 low.

The Sterling has been under pressure by the ascend of the dollar for the past few weeks. On Tuesday, higher-than-expected US inflation data boosted the dollar at the expense of competing currencies.

UK Unemployment Rate dropped to 3.6% on Tuesday compared to last month’s 3.8%. Britain's jobless rate hit its lowest since 1974 providing some support for the Sterling. At the same time, wages in the UK, as estimated by the Average Earnings Index, rose 5.5% compared to the previous print of 5.2%.

UK monthly GDP data released on Monday fell below expectations, putting pressure on the Sterling. Britain’s GDP grew by 0.2% in July, against expectations of a 0.3% growth. This was higher than the previous month’s data, however, which had shown a contraction in GDP. The BOE has warned that recession is expected to hit the UK in the fourth quarter of this year, and is forecasted to last for five quarters, until the end of 2024, with GDP falling to 2.1%.

Last week marked historic changes for Britain, seeing a new monarch and Prime Minister within a few days. The Sterling dropped after Queen Elizabeth’s death on Thursday but did not exhibit high volatility, as the Queen’s health had been deteriorating for some time.

A climate of political uncertainty has been putting pressure on the GBP over the past few months, especially after former PM Boris Johnson’s resignation in July. On Tuesday, Former Foreign Secretary Liz Truss formally became UK’s next Prime Minister, bringing a measure of stability and propping up the Sterling.

Truss’ appointment provoked mixed reactions to markets, as she had questioned the BOE’s mandate in the past and her future stance towards the BOE may undermine the Sterling. Truss, however, announced an ambitious plan to prop up energy in the UK and reduce the average cost of energy for households, by funneling billions to the sector.

The much-anticipated BOE monetary policy meeting, which had been scheduled for the 15th, has been postponed to the 22nd following the death of Queen Elizabeth. In its latest monetary policy meeting, the Bank of England raised its interest rate by 50 bps, bringing the total interest rate up to 1.75%. The BOE has adopted a moderate stance, trying to strike a balance between battling inflation and supporting the sluggish economy. Markets are pricing in a rate hike of at least 50 bp at the next BOE policy meeting in September.

Britain’s poor economic outlook is preventing a more hawkish fiscal policy and is hampering the BOE’s attempts to bring inflation down. UK inflation reached double digits in July, with CPI climbing to 10.1% on an annual basis and is expected to rise even higher in the following months. Soaring energy and food prices put pressure on British households.

Inflation CPI and PPI data due on Wednesday may have a considerable impact on the currency ahead of the next BOE monetary policy meeting next week.

GBPUSD 1hr chart

The Yen plummeted against the dollar on Tuesday, dropping near to last week’s 24-year low. The USD/JPY spiked up, climbing above 144.5. If the USD/JPY pair falls, support might be found near 138.0 and further down at 134.2. If the pair climbs, it may find further resistance at the 1998 high of 147.7.

The increased divergence between the US and Japanese monetary policies has widened the gap between their respective bonds, putting pressure on the Yen. The BOJ keeps bond yields low, weakening the Yen. On Tuesday, high US inflation data increased the odds of a steep Fed rate hike this month.

The Yen’s extreme weakness seems to have finally caught the attention of Japanese officials. BOJ Governor Haruhiko Kuroda has stated that sudden moves in the currency increase uncertainty and are undesirable. Seiji Kihara, the deputy chief cabinet secretary of the Japanese government, stated recently that Japan's government must take steps as needed to counter excessive declines in the Yen. Increasing comments by Japanese officials expressing concern about the Yen’s weakness may hint at a hawkish shift in the BOJ’s monetary policy.

The BOJ maintains its ultra-easy monetary policy, keeping its main refinancing rate at -0.10%. Japan continues to pour money into the economy, while other countries are adopting a tighter fiscal policy. The difference in interest rates with other major Central Banks puts the Yen at a disadvantage, driving its price down.

Inflationary pressures are increasing in Japan, mainly due to the high cost of imported energy. The combination of a weak currency, low wages, and rising inflation is burdening Japanese households.

Minor economic indicators are scheduled to be released on Wednesday for Japan, which may affect the Yen slightly.

USDJPY 1hr chart

Written by:
Myrsini Giannouli

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Understanding Motors and Reducers

Gear Motors

Gear motors are systems that are essential when correctly and effectively moving most motor-powered machines. Given their importance to adjust the speed of the mechanism, it is essential for us to know what they are, their components and their main types.

The gear reduction ratio (the ratio of the number of teeth between input and output shafts) is also known as the transmission ratio.

Essentially, a gearmotor is a pairing of gear reducer and ac or dc electrical motor. The gear and the motors are combined into one unit.

Gear Reducers

A gear reducer is a mechanical transmission device that connects a motor to a driven load. It is also known as a gearbox.

It allows you to modify the torque and speed between a motor and a load. Reduction gear assemblies are made up of series of gears.

A gear reducer is used to adapt the characteristics (torque and speed) of the input and output axis of a mechanism. This is why you have to know the torque and rotation speed.

It is therefore appropriate to ask yourself about the torque first and foremost. A reducer increases the torque of your motor and thus allows a receiving member to rotate under the impact of a new torque. Gear reducer manufacturers sometimes indicate the minimum and maximum torque (expressed in newton meters, N.m) that can be supported by each of their products. The torque density varies according to the gear reducer. For example, planetary gearboxes have a high torque density.

The other purpose of a gear reducer is to reduce the motor speed and we recommend that you take into account the ideal reduction ratio for your use. Based on the rotational speed of your motor, the reduction ratio is used to determine the output rotational speed. This information is also indicated by manufacturers on their product pages. It is given in revolutions per minute.

Lastly, you should ask yourself what kind of gear reducer assembly is most appropriate for your application. The input and output shafts of your gear reducer can be coaxial, parallel-shaft or orthogonal. This depends on your intended use.

Contact us today and we can assist you in finding the right solution for your application!
Call us at 815-943-9111 or email at

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NEW YORK — The US Southern District of New York Court March 31 dismissed a lawsuit claiming Kellogg Co. exaggerated the amount of strawberries in Frosted Strawberry Pop-Tarts through misleading labeling. The court ruled plaintiff Kelvin Brown failed to plead that a reasonable consumer would find the front label misleading.

Mr. Brown filed the lawsuit Sept. 5, 2020, saying the front of the package exaggerated the amount of strawberries in the product by showing an image of half a strawberry and an image of the product revealing a dark red fruit filling. The front label omits pears and apples, but the two fruits are found on the ingredient list. The lawsuit also stated a synthetic food coloring, Red No. 40, gave the strawberry-pear-apple combination in the filling a dark red color. If Mr. Brown would have known about the alleged misrepresentations, he would not have purchased the product or would have paid less for it, according to the lawsuit.

Kellogg moved to dismiss the case on April 16, 2021, contending the front label does not represent that strawberries are the only fruit ingredient in the filling, that the filling contains a specific quantity or proportion of strawberries, that the filling contains ade minimisamount of non-strawberry fruits, or that the product has nutritional benefits derived solely from strawberries. Kellogg also contended the ingredient list resolves any ambiguity about fruit ingredients in the filling and the use of red food coloring does not exaggerate the amount of strawberries in the filling.


The works of Edward Munch (1863-1944) have fascinated me more and more over the years. In Puberty of 1894-95, certain formal and perspective distortions typical of his mature language, to which this painting belongs, are not present. This work has a more intimate or apparently less explosive character than his other more violent and strident works, both in terms of colour and formal forcing. The explosiveness of this painting resides in different characteristics, which, given the theme of titling, has prompted the author to take a different path, deeply consistent with his language, but that departs from that dynamism extrinsic in the escape of the infinite and dizzying streets or / and in the palette noisy and contrasted that even when it represents scenes of greater stasis gives the complex an energetic animation of the events shown, whether they are indoors or outdoors, or even just landscapes without the human presence. In Munch’s work, everything is alive and quivering.

In this work, on the other hand, a greater firmness seems to reign, the composition is made up of the bed placed horizontally, on which the figure rests at the centre of the scene in a vertical position, thus constituting a perfect central intersection of horizontal and vertical, the structure of immobility par excellence. Stasis replicated by the posture of the girl with her knees and narrow legs, on which she crosses her arms as if to close, not to show. The gaze is fixed, hypnotized or inanimate, also motionless like the figure, which seems to suggest more a mannequin than a human body. Such immobility is contrasted with the girl’s shadow with its diagonal and ascending momentum, a shadow that does not appear convincing, neither from the formal point of view, not presenting the characteristics of that body, nor from the dimensional point of view, appearing oversized. Its spectral mass looms over the girl, constituting the only dynamic motion placed to contrast and break the immobility of the rest of the composition. Munch gives form to something difficult to narrate through an image, the adolescence of a girl whose revolutionary movements, moral and hormonal, are totally internal. The frenetic and chaotic whirlwind of those inner movements is embodied by the monstrous shadow that rises from the immobility of the figure like a cry, like an inner ghost that could overwhelm the girl herself. That presence is a threat that dominates her and Munch, through the nervous and decomposed brushstrokes, assigns her a whirling and disturbing movement, is the only thing that moves in that image and does it like crazy. That monstrous presence is something that the painter knows well and that led his sister, barely twelve years old, to death from tuberculosis, a disease of which his mother died a few years before the young Johanne Sophie. What is truly surprising, and that makes this painting a masterpiece, is how Munch, just over thirty years old, was able to tell at the same time a personal story painful in a form that becomes however plural and universal in that typical condition shared by any girl who approaches adolescence with the psychological-hormonal burden that follows. Even the simple visual narration of such an event is no small thing, being an inner event, both in its adolescent passage, and in the pain resulting from the death of his beloved sister.

Therefore, the apparent static nature of this work is brought back, through the abominable spectral presence of shadow, to that anxious dynamism typical of its production. And, moreover, observing the chromatic mixture, we discover that it is dense with a gesture that stirs up every single fragment of the painting. The palette based on combinations of browns, and which could, precisely because of this chromatic proximity, enhance its stability, is shaken by the application that dirties and contaminates the individual areas of the work and for which each of them never appears to be constituted or dominated by a single colour. So, if on the one hand the typology of the chosen colours gives the complex a leaden and dirty atmosphere, on the other hand their application amplifies the “dirty and polluted” component, multiplying the chromatic nuances that, together with the gestures, give it that dynamism that has been taken away from the main compositional structure.

In every gesture, in every chromatic stain, is contained the drama of the biographical events of the author, who could not but paint what he was, but that through his expression gives body to the social drama of an entire age against which he hurled himself, even if he does so in a more declared way in other works than Puberty. And also for this reason, this work retains a more intimate character, making it seem even more extraordinary its universality.

POOL Phoebe, Impressionismo, [1967], Milano, Rusconi libri, 1988.


The idea of angels has continued to boggle even the most brilliant minds for centuries. What are they? Who are they? And why can we not agree on if they are real or not?

In the bible, there are countless tales of angels visiting the earth at significant moments. There was the angel who visited the Virgin Mary to inform her that she was carrying the Christ Child. There was the angel who visited the frightened shepherds on the night of Jesus' birth. And there are many instances when angels appeared to comfort, save or guide others throughout trying times.

But what do they look like exactly? We are all accustomed to many interpretations of angels: chubby, winged cherubs; tall, ever-glowing, winged humans; harps, robes, halos and so on.

Does anyone truly know what they look like?

Who are angels?

First of all, do we know who angels are? Or what their purpose is?

The Bible simply describes them as divine messengers of God. They are frequently mentioned, and multiple times Jesus speaks about them administering to the earth.

We also know from Revelation that the Devil has his own angels who were cast from heaven along with him.

All in all, God sent angels to earth during particularly perilous times to comfort, guide and strengthen His children.

Do angels look human?

The answer is yes. Angels are not the chubby, winged cherubs we see in so many statues and other forms of art. Angels look very much human.

Some people who have encountered angels describe them as normal-looking human beings, only for them to vanish after a miracle or significant circumstance has occurred. In the scriptures, others have described angels as taking on a divine, startling and even frightening appearance. However, when the angels first appear, they often say phrases such as "Do not be afraid" and "Fear not."

Daniel gave a very detailed description of the angel whom visited him:

Daniel also describes the angel as looking like a great and glorious man. In fact, the earthly men surrounding Daniel quickly cower and flee in fear of the powerful angel.

Therefore, angels may appear in different ways, but there is no doubt they look human.

Do angels have wings?

Nowhere in the Bible does it describe angels with wings.

One thing to consider when we question if angels have wings is this passage from Genesis 1:26-27: "And God said, Let us make man in our image, after our likeness [...] So God created man in his ownimage, in the image of God created he him; male and female created he them."

As human beings, we do not have wings, and if angels are also created in God's image, they do not have wings either. They are glorified human beings.

How can you see angels?

There are many instances of angels appearing to humanity, but what determines who they visit?

Today, angels still actively visit and administer to those who need them - just as often as they did when Jesus was on the earth. We only need to take a moment to feel their presence and recognize our feelings for what they are.

I think there are times when we would be surprised and elated to know just how many angels are watching over us each day. They come to our aid when we believe and ask God in faith.

If you'd like to see angels in your own life, try praying to God to help you. You can ask him to help you recognize the angels in your life and feel them around you. You might find angels are the everyday people you know and love. Through their acts of kindness and service, they'll carry a heavenly spirit about them. They'll uphold all the qualities and traits of a true servant and messenger of God.

By seeking angels out in your own life, you will find everlasting comfort and joy and you'll see angels surrounding you.

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How to buy Dole stock

Learn how to easily invest in Dole stock.

Fruit and vegetable giant Dole is expected to go public later today and commence trading on the New York Stock Exchange Friday under the ticker symbol "DOLE," according to a Form F-1 filed with the US Securities and Exchange Commission.

The company slashed its price range on the offering to $16 to $17 per share from $20 to $23 per share, a move that slices its targeted valuation by more than $400 million.

The IPO news comes months after Dole Food Company merged with Ireland's Total Produce to form the world's largest fruit and vegetable supply business.

How to buy shares in Dole

  3. Confirm your payment details. Fund your account.
  4. Research the stock. Find the stock by name or ticker symbol – DOLE – and research it before deciding if it's a good investment for you.

Dole stock price (NYSE: DOLE)

Use our graph to track the performance of DOLE stocks over time.

Dole shares at a glance

Information last updated 2022-10-02.
Latest market close$7.77
52-week range$7.20 - $15.41
50-day moving average $8.90
200-day moving average $11.33
Wall St. target price$13.78
PE ratio N/A
Dividend yield $0.32 (4.13%)
Earnings per share (TTM) $-0.37

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Is it a good time to buy Dole stock?

Dole price performance over time

Historical closes compared with the close of $7.77 from 2022-10-05

1 week (2022-09-29) 6.44%
1 month (2022-09-06) -14.99%
3 months (2022-07-06) -9.65%
6 months (2022-04-06) -39.01%
1 year (2021-10-06) -49.81%
2 years (2020-10-02) N/A
3 years (2019-10-02) N/A
5 years (2017-10-02) N/A

Is Dole stock undervalued or overvalued?

Valuing Dole stock is incredibly difficult, and any metric has to be viewed as part of a bigger picture of Dole's overall performance. However, analysts commonly use some key metrics to help gauge the value of a stock.

Dole's EBITDA (earnings before interest, taxes, depreciation and amortisation) is $184.5 million.

The EBITDA is a measure of a Dole's overall financial performance and is widely used to measure a its profitability.

To put Dole's EBITDA into context you can compare it against that of similar companies.

Dole financials

Revenue TTM $8.8 billion
Operating margin TTM 0.75%
Gross profit TTM $349.1 million
Return on assets TTM 0.49%
Return on equity TTM -0.62%
Profit margin -0.2%
Book value $11.61
Market capitalisation $692.6 million

TTM: trailing 12 months

Dole share dividends

Dividend payout ratio: 34.78% of net profits

Recently Dole has paid out, on average, around 34.78% of net profits as dividends. That has enabled analysts to estimate a "forward annual dividend yield" of 4.13% of the current stock value. This means that over a year, based on recent payouts (which are sadly no guarantee of future payouts), Dole shareholders could enjoy a 4.13% return on their shares, in the form of dividend payments. In Dole's case, that would currently equate to about $0.32 per share.

While Dole's payout ratio might seem fairly standard, it's worth remembering that Dole may be investing much of the rest of its net profits in future growth.

Dole's most recent dividend payout was on 7 October 2022. The latest dividend was paid out to all shareholders who bought their shares by 15 September 2022 (the "ex-dividend date").

Dole's dividend payout ratio is perhaps best considered in relation to those of similar companies.

Dole overview

Dole plc engages in sourcing, processing, marketing, and distribution of fresh fruit and vegetables worldwide. The company operates through four segments: Fresh Fruit; Diversified Fresh Produce - EMEA; Diversified Fresh Produce - Americas and ROW; and Fresh Vegetables. It offers bananas, pineapples grapes, berries, avocados, deciduous fruit, and organic produce; value added salads, which includes packaged salad and meal kits; and fresh packed vegetables, such as iceberg, romaine, leaf lettuces, and celery, as well as health foods and consumer goods. The company serves retailers, wholesalers, and foodservice customers. Dole plc is headquartered in Dublin, Ireland. .

Frequently asked questions

What percentage of Dole is owned by insiders or institutions?
Currently 32.234% of Dole shares are held by insiders and 39.356% by institutions.
How many people work for Dole?
Latest data suggests 38,500 work at Dole.
When does the fiscal year end for Dole?
Dole's fiscal year ends in December.
Where is Dole based?
Dole's address is: 29 North Anne Street, Dublin, Ireland, D07 PH36
What is Dole's ISIN number?
Dole's international securities identification number is: IE0003LFZ4U7

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Decline of British Empire

Full Name
The Decline of the British Empire
Start Date
End Date

Formerly having the greatest imperial power in history, the British Empire’s decline was a hit directly from the impact of World War II. With the empire’s establishment dating back in the 16th century, the British Empire’s expansion accelerated during the 18th century. It has become the largest empire to have ever existed by 1913, covering around 25% of the world’s land surface, including large portions of North America, Australia, Africa and Asia, while other areas - especially in South America. Then known as “the empire on which the sun never sets”, its decline in 1947 made Britain lose the jewels in its crown, kickstarting a domino effect across the empire. By 1967 more than 20 British territories were independent. Little remains of British rule today across the globe, and it is mostly restricted to small island territories such as Bermuda and the Falkland Islands.


Mosque of Cordoba

Who I am
Aina Prat Blasi

Author and references

La Mezquita or Mosque of Cordoba it is a fascinating building that embodies the many political and religious changes that the city has undergone over the centuries and today is the Cathedral of Santa Maria Assunta. Built in 785 by Emir Abd ar-Rahman I on the site of an ancient Visigothic church, the Mezquita is opulent and luxuriant: gold mosaics, gigantic arches with 856 columns and plays of lights run along the 23 square meters of the wonderful building work of Islamic architects.

The main entrance is the fourteenth century Gate of Forgiveness in Mudejar style which is located next to the XNUMXth century Muslim minaret, the Torre del Alminar. Inside is the magnificent Patio de los Naranjos, the orange courtyard, which leads to the prayer room. In front of this gate is the mihrab, the prayer niche of the qibla wall which indicates the direction of Mecca.

In the center of the building is the Christian cathedral built in the 1520th century, with a beautiful Capilla Mayor and a baroque choir from 1600. In front of the mihrab is the maksura, the place where the caliphs prayed, the most decorated parts of the mosque. For example, the mihrab portal is made up of XNUMX kilograms of gold mosaic tiles donated by the Christian emperor of Byzantium, Nicephorus II Phocas.

In 1984, the historic center of Cordoba, including the Mezquita, was declared a World Heritage Site by Unesco.

Entrance tickets to the Mezquita

The Mezquita is certainly the most visited attraction in Cordoba and to visit it you need to buy an entrance ticket or take part in a guided tour. There are different types of tickets: choose the one that's right for you! We advise you to visit it in any case in times of less crowds, that is in the early morning or late afternoon.

Skip-the-line ticket to the Mezquita

Given the large influx of tourists to the Mezquita, we recommend that you buy a ticket with priority entrance: it will allow you to save a lot of time queuing at the entrance, especially during the busiest periods.

Ticket + guided tour of the Mezquita

If you want to deepen your visit to the Mezquita with an official tour guide who will accompany you throughout the tour, buy a ticket with a guided tour among the following that we offer.

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Canon, or tetsu-tsutsu

A set of bells on a stand consisting of high and low pitched bells with a hollow metallic piece in between of indefinite pitch. The 2 bells are usually tuned to a 3rd or 4th step, as in Latin music. The middle piece makes a metallic "ching" sound. The "canon" (or "tetsu-tsutsu" in Japanese) is used to play the basic beat.


Man claims that fun center caused him to slip and fall

A man in another state recently claimed that an entertainment center’s staff and owners caused him physical harm due to their carelessness. Specifically, he asserted that the center caused him to slip and fall and suffer injuries. He has thus filed a lawsuit against the center, seeking damages. In the same way, anyone who is hurt at an establishment in Kentucky due to its negligence has the right to seek justice in civil court.

The man who filed the lawsuit claimed that he was at a trampoline fun center for a birthday party one day when his slip-and-fall accident happened. He was reportedly attempting to go up an obstacle at the center. However, all of a sudden, he came across some beads on the floor. He asserted that the beads caused him to lose his balance and slip and fall.

According to the man’s lawsuit, the loose beads were scattered all over the floor. He claimed that he did not know that beads were on the floor, and it was not unreasonable for him to expect the floor to be clear. In addition, the man asserted that no employees were nearby to warn patrons about the presence of the beads. As part of his lawsuit, he is seeking over $50,000.

Sometimes, businesses in Kentucky and elsewhere fail to properly address hazards at their properties, which can cause guests to slip and fall and thus suffer harm. In this situation, injured customers have the right to pursue financial damages. Monetary compensation in a successfully fought suit may help with addressing hospital bills, pain and suffering, and lost wages stemming from the accident.


Aldous Ng

CEO, CU Coding Limited

With many years of solid technological experience, CU Coding CEO Aldous Ng has big dreams of enhancing digital communication. "Turning vast information into vital assets" is the vision of CU Coding, an Independent Software Vendor (ISV) for applications by Network Coding technology. The core technology behind is invented and researched in the CUHK for the last 20 years. Network Coding is a completed project in the Areas of Excellence (AoE) of the UGC, which is recognized internationally for the state-of-the-art technology. With the solid technology foundation, CU Coding has won numerous awards with the success of many Smart City use cases in Hong Kong and China. In recognition of his achievements, Aldous was named Distinguished Alumnus of CUHK Engineering Faculty in 2017 and Distinguished Alumnus of Shaw College in 2019.

“If you can dream it, you can do it! You are never a loser until you quit trying.”


Short Sharp And Steep Mountain Bike Technique

Short Sharp And Steep

Technique / Skills

What goes up must ultimately come down. Long flowing descents are for many the highlight of their ride. Mother nature and trail designers alike do not always have the faint hearted in mind and when sections become suddenly very much steeper it is easy for fun to give way to fear, to have your flow broken as your mojo fades or, in more extreme cases, disappears in a cloud of dust.

Firstly let us deal with semantics. To many riders a short sharp steep section will be referred to as a ‘drop-off’, for the sake of argument that is how I’ll be referring to them through this article. We are not talking ‘drops’ (which will require the wheels to leave the ground) but where the trail ahead ‘drops off’ at a dramatically increased gradient but can still be rolled.

Mastering short, steep sections of trail will allow you to undertake a far wider range of trails and terrain. No-one likes the feeling of having to dismount and walk a section (added to which walking a bike down can be as (perhaps even more) precarious than riding it. Armed with both the correct knowledge, and the ability to apply that knowledge to your riding, less and less will you be forced to dismount and perform the often-comedic routine of descending a steep section pushing your bike with all the grace and dexterity of Bambi on a frozen pond.

Drop offs put both your physical and your psychological skill set to the test. Understanding the physical elements of your riding is one thing, having the nerve to apply them when psychologically challenged is another. Flight based responses (as we have identified in other issues) are instinctive but wont necessarily help. Learned responses required to master steep terrain can quickly be developed to replace ‘gut instincts’. Gut instincts are reactions to the perceived threat and danger you face but have little to do with the dynamics of riding a bike and good technique.

Although gradients, trail surfaces and technicality of sections will vary greatly the underpinning principles that will enable you to tame them will not. The same core principles and skills elements will need to be considered for every ‘drop off’. The degree to which these skills are applied might change, margins for error may narrow and penalty for failure may rise but the thinking behind the techniques, the physics, will not.

Underpinning Principles: Under-rotation

We have already identified the principle of under-rotation in an earlier issue (issue 2) and seen how understanding this concept will help with various aspects of riding. Although beneficial to your riding in a general sense, applying this principle either knowingly or unknowingly is crucial when it comes to riding ‘drop offs’.

To recap, under-rotation is concerned with how your mass interacts with the bike - your mass should be driving the bike not simply balanced on top of it. If the bike stalls or checks against terrain, pitches forward sharply, or is slowed by you applying the brakes, you need to consider what will happen to your mass. You do not want it to fly up and over bike. Set up your core connection with the bike correctly and you will allow your mass only to push down, into and through the bike. Under rotation will not only ensure that you keep the bike between you and the ground but will help drive the bike though a section, gain traction, brake with confidence and control where necessary, or pump for power and speed. It is a fundamental principle that needs to be applied.

‘Under rotation is not a case of simply getting your weight ever further back on the bike and seeing it as such (or refuting it’s importance because you don’t understand this) this is a mistake that will leave you wanting.’

We will look at how various core skills contribute to this later in the article but as a recap consider the following:

On the flat your with cranks level (and heels dropped) feet will be equally distanced fore and aft of the bottom bracket. Keeping equal pressure on each foot is key to a balanced position on the bike. Your hips slightly rear of the bottom bracket and your shoulders slightly in front of that point will mean that you core mass is centered. As terrain steepens you are going to have to shift your body position to keep that equilibrium. It is easy to allow your body to rotate too far forward as the nose of the bike drops into a descent. If this happens your mass will be driven towards the front of the bike and the potential pivot point of the front hub. Once hips overtake your feet your legs no longer bear so much of your weight and you cannot push force down, into and through the bike effectively. You will have gone from driving the bike to being conveyed by it - any attempt to control your speed is going to put much more pressure on your arms / hands (they are all that is left from stopping you overtaking the bike) and restrict your ability to control your speed dramatically. Your centre of gravity will be raised from the low point of the bottom bracket to a high point above the bars, which is a long way from ideal. As your bike reaches the bottom of a drop off and the compression at the front end is at it’s maximum you’ll struggle to stop your mass getting driven even further to the front of your bike or beyond it. There are times shifting your weight forwards is desirable and necessary for sure, but it should be a conscious decision to so and controlled rather than simply slumping or being thrown there because momentum and poor core understanding have combined to pin you there. Dropping the wrist will help to ensure that when weight is pushed forward it travels down and through the bars not simply on top of them and help to drive the bike.

Underpinning Principles: Projection

Again this is a principle that needs to be understood and applied to all aspects of riding but as things get suddenly steeper there is more to do and it is important not to get caught up in the moment but be thinking and making decisions further ahead of the bike. Your thinking should be done before your ‘doing’. Knowing what you want to be doing way before you need to do it will have positive connotations both physically but also mentally. It will allow you as a rider to keep calmer and be more considered in your approach rather than riding by the seat of your wont find much decision making capacity down there! Riding blind into a drop off having not seen it before you are indeed going to have to make some pretty quick decisions and that may be as you are passing the point of no return but that is still not an excuse to stare down the barrel of your forks and try and affect an outcome that is already inevitable. You don't need to have seen the exact nature of the drop as you ride in if you have already developed good muscle memory and trained your body to react in a certain way when presented with a certain scenario. A successful outcome relies on having experienced similar terrain and to a certain degree developed a level of ‘unconscious competence’. If you are not happy that you will react with enough speed and in the right way to a section that lies ahead you should consider having a look at it first. When approaching a drop off, by it’s very nature you may not be able to see the section. Controlling your approach speed might give you enough time to make your decisions (or stop before the point of no return) alternatively you may chose to take a look at it first before riding in.

Projecting ahead of the bike does not always require you to be on it!

You and Your equipment

As ever if your bike lets you down it will effect your performance. Of particular relevance when dealing with drop offs is your ability to control your speed, shift your weight and deal with compression as you hit the transition. With that in mind correctly performing brakes are going to be important. A brake in need of a bleed may well work sometimes and others fail you leaving the lever clamped to the bar but not the callipers to the rotor. A brake that does not work at all is arguably less danger than one that works intermittently. If you know it wont stop you, you are not going to attempt a section which requires it, if it fails you when you decide you need it, trouble will not be far way. Equally important is your ability to employ the brake from the position you are in without the need to roll your wrists forwards which will weaken you core interaction with the bike and can lead to over rotation and less ability to deal with compression. You need to be able to still reach your levers with a dropped wrist when the bike becomes inverted to some degree. Raising the level position SLIGHTY will allow this. Just to be clear that does not mean they should be parallel to the ground but slightly raised from 45 degrees and easy to reach when the bike pitches forward and you shift slightly rearwards.

Saddle height can infringe your ability to move freely around the bike. As the bike rotates forward you need to be able to allow the saddle to pass between your legs and not rotate you forwards at the same rate. If your saddle is too low and you may feel less stable additionally when it comes to pedalling you will suffer big time. A dropper post will allow you to quickly adjust your bike to the terrain but finding an optimum point where pedalling is not compromised too greatly but freedom of movement is maintained is the ideal. A by product of riding with a dropped heel means you can get full leg extension when pedalling but have good clearance when standing on level cranks.

The saddle is not the only thing that can restrict movement. A low hanging baggy short might let everyone know who makes your underwear, it may make you ‘feel down with the kids’, but if they snag on the nose of your saddle as the bike pitches forwards it will cause issues. Equally if it stops the saddle passing back through your legs as the bike levels off at the bottom you’ll create problems for yourself. Stuck too far forward on the way down or hanging too far out the back when pass through the transition are both problems easily avoided. Don’t let your clothing result in you becoming quite literally a fashion victim. As far as I am aware, looking ‘cool’ doesn’t guarantee a shorter waiting time for an x-ray.

Suspension is going to get a work out. Your forks will be put through their paces. Experimenting with compression rates and rebound will allow you to fine tune your performance. To soft and forks can bottom out too early, running them to rigid and you are not going to get much assistance from them and they will compensate less for any shortcomings in technique and correct body positioning. Don’t forget as vital as the bikes suspension set up is, you the rider can use the 18 or so inches of travel that arms and legs allow to good effect, but you must stay supple - as with any technical section getting ‘tight’ is going to cause problems.

As alluded to time and time again, your feet are your primary point of contact and losing contact with your pedals will have serious repercussions, as terrain gets steep. Generally your heel should be dropped and unless pedalling or cornering, cranks should be level. As the bike rotates away from you keeping heels dropped will ensure your mass stays where you want it and your feet stay planted to your pedals. An added benefit is that as the rear wheel wants to move up and over bumps a dropped heel will encourage you to suck up the back wheel rather than be rotated forward. It will also allow you to push into the bike and counter momentum that will potentially start to push you forward as you try and control your speed. On a steep slope your wheelbase is effectively shortened dramatically so the margin for error in terms of getting too far forward is narrowed. Keeping your heels dropped (and hips behind them) allows you to use your legs to control and deal with the forces of momentum. It will help to ensure that your mass contributes positively to the braking process rather than simply overtaking the bike. Up on your toes, heels raised, you are asking at worst to be rotated forward to a point of no return. Even if you don’t get beyond the point of no return you will be putting far too much burden on your hands and arms. If you are in doubt think which is easier, a push up or squat? With your weight remaining through your feet you are far less likely to find yourself gripping on ever tighter. Gripping too hard to control over rotation will lead to a general tensing of the arms and thus deaden your body’s natural suspension.

The final consideration with footwork is maintaining a level crank. As the bike rotates forward and you shift clear of the saddle it is easy to end up with rear foot dominance and as a result more weight rocks onto your back foot. Your trailing foot will then drop from the level position to a lower point. As the front wheel pitches down you do not want a pedal catching on the lip of the drop. As you rotate back increase the pressure on your lead foot so as to keep your cranks level. Your rotation backward and down is around the pedal axles not the bottom bracket.

Body Position

You are going to have to allow the bike to rotate forward into the drop off. Rotating forward at the same rate might be okay if:

  • You are not planning anything in the way of speed control.
  • The transition at the bottom is not too severe, more rounded rather than a sharp change.
  • The trail surface is smooth and front wheel’s progression is not going to be hindered by roots, rocks, etc.
  • You simply enjoy the pain associated with face planting.

Assuming all those boxes are not ticked you will need to allow the saddle to pass between your legs but it is not a case of extending as far back as your limbs will allow. Push so far back that your legs are fully extended and locked out and they wont be much use in terms of energy management. On top of this, when the bike levels off at the bottom you are going to struggle to get centred on the bike quickly enough and risk looping out. Once you have cleared the saddle it is more a case of softening the legs bringing your weight down as well as back. Hunkering down above the rear hub will allow you to deal with the bumps on the way down, control your speed and get central more easily as the bike levels off. Just clear of the saddle you can even afford to bring your upper body forward if desired - it should not feel that you are backing off from the trail by extending as far back as possible.

Speed Control

If every second is being counted then you will be trying to ride the section a fast as possible, less braking means less chance of overtaking the bike. If we do want to control our rate of acceleration however, then good braking technique is crucial. Remember that it is easier to affect your rate of acceleration than your rate of deceleration. Once panic sets in there is likely to be snatching at brake levers rather than any progressive braking. When gut instinct takes over (flight based responses) you are more likely to tighten up on the bike, more likely to drop your head and think only about the current situation and not think ahead of the bike. No doubt the bike is going to accelerate as you enter a steeper section or drop off. If it is a near vertical entry you are going to have to go with the flow to a degree but that does not mean just letting go and hoping for the best. Controlling the entry speed is a good idea. Go in too fast and you may well exceed the speed you are comfortable with and freeze up, tighten up or lose your nerve all together. On the other hand if your slow speed balance skills are not great going in too slowly will cause more problems than it solves. Wobbling from side to side at the lip is not ideal and will make sticking to your preferred line difficult. If you are approaching too slowly and find yourself wobbling it is probably a sign that you are not all there in terms of the psychological aspects of riding that drop off. Finally when it comes to speed control getting the balance between front and rear brake is important. On a steep enough slope (and certainly a drop off) a locked back brake alone will not slow you down in fact wont even stop you accelerating, all it will do is bounce around behind you at the mercy of every root and camber. This will send far more shockwaves through the bike bouncing you around more. Much of the speed control is going to come from correctly using your front brake. Locking this up is definitely not a good idea but certainly you will need to be using it. Overall you should be expecting your speed to increase through the section (like any other) so don’t panic when it does - keep a cool head and remember controlling your acceleration is one thing and more than possible - stopping is not.

The Psychological Factors

Commitment must be there at the entry point (this is not the lip but well before), it must remain high through the section and beyond, losing your nerve as the front wheel drops will have a very negative impact and invariably that will result in being parted from your bike. Confidence can rise and fall faster than a lift in the Empire State Building. Build confidence by building up the size and severity of drops. Success and repetition are the sure fire ways to keep confidence on the up. On the days you are less confident or when pushing yourself to new levels of technicality think through the section and ultimately if it doesn’t feel right save that drop for another day. ‘Giving it a go’ is not a positive frame of mind, don’t just think you can do it - know you can.

Controlling the emotions and not resorting to flight and flight responses is crucial - you will need to move dynamically and fluidly on various axis. Stay fluid, don’t hold your breath or brace yourself as if you are about to crash.

‘Get tight with fright and it could well be good night’.

Concentration as ever will require you to keep mentally as far ahead if the bike as possible. Think ahead, look ahead, don’t get drawn into the now. Look for positive outcomes - where you want to be, not where you do not.

As a rider you should ride into a section because you want to and are ready to both physically and mentally. Ride it because you want to not because your mate wants you to. A&E departments are often frequented by riders that were looking to save face... Only to find that the outcome was quite the opposite!

As with all techniques work on correctly applying your physical and psychological skills on drop offs within your capability where you can focus on technique over terrain and build up towards the steeper and more technical once you are happy that the foundations are strong. Riding drops and getting them right is a great buzz. It will open up a far wider range of trails particularly those off the beaten track, free from risk assessments and HSE guidelines. Developing your skills will add to your freedom to roam, so enjoy the ride and most importantly... Don’t forget the odd whoop of delight when you pin that drop off!

This technique article was in Issue 14 of IMB.

By Richard Kelly

Problems? Ask Below


How do you change the clip length on a TikTok?

Part 1 How to Adjust Length of Uploaded Clips on TikTok Launch TikTok on your phone and tap the “Upload” option to the right of the record button. Select the video you want to upload to TikTok and click “Next”. Use the slider at the bottom of the screen to trim the video to the length you’re comfortable with.

How do you change the length of multiple uploaded clips on TikTok?

Trim the TikTok Video Recorded Now Now you can tap on the REC button to take a video. Step 2: After that, you should tap the Adjust Clip button, and a bar will appear at the bottom. Just drag the slider on both sides to adjust the TikTok video length easily.

How do you adjust clips on TikTok 2021?

a)Trim a Video Captured via TikTok Step 3: On the right side of the screen, you will see some options like Filters, Adjust Clips, Voiceover, and a Dropdown icon. Tap on Adjust clips, all your recorded clips are available for trimming and further editing as reshooting clip or deleting.

What is the max length of TikTok video?

In 2017, TikTok bumped up the video length to 60 seconds. That began to increase the amount of time people spend on the app. By 2018, TikTok had over 300 million users. Since then, TikTok began testing longer uploads and extended the maximum video length to three minutes in July 2021.

Why are TikTok songs so short?

Since TikTok doesn’t allow you to combine multiple pieces of music directly, or repeat, reverse music, the most direct way to make music longer on TikTok is recording videos longer than 15 seconds. Change the duration to 60 seconds and record yourself or your performance.

How do you extend a song on TikTok?

Tips: If the music is longer than the TikTok video, drag the end of the audio clip on the timeline until it matches the length of the video. If the music is shorter than the TikTok video, hit Ripple Delete and choose Time Stretch. Next, drag the end of the audio clip until it matches the length of the video.

How do you get the 3 minute option on TikTok?

Go to the TikTok application and run it. Proceed to the camera display where you can choose between ’15s,’ ’60s,’ or ‘3m’ from a swipe across menu directly above the huge red record button when you’re on the camera interface.

How do I trim a TikTok video draft?

Go to your profile page, and tap on the ‘Drafts’ folder. Tap on the draft you want to edit to open it. If you want to edit the video itself, click ‘Back’ in the top left corner. From here you’re able to add new clips, music, filters, voiceovers and more.

Why can’t I make 3 minute videos on TikTok?

Previously, TikTok videos could be up to 3 minutes in length following a change in July 2021. Before that, the limit was 60 seconds after initially expanding from 15 seconds.

Why are some songs on TikTok only 15 seconds?

Google search has only revealed that TikTok has licensing restrictions that only allow 15 seconds, but there are TONS of songs available for 60 seconds. The longer you keep people watching the better the algorithm likes you (allegedly), so it’s smart to keep people on for as long as possible.

How do you stitch longer than 5 seconds?

Press the “Stitch” button. Select up to five seconds from the video. You can trim the clip to your preferred duration. Record your addition to the Stitched clip.

How do I lengthen a video on my Iphone?

Open the Photos app and tap the video that you want to edit. Tap Edit. Move the sliders on both sides of the video timeline to change the start and stop times. To preview your trimmed video, tap the play button . Tap Done, then tap Save Video or Save Video as New Clip.

How do you trim a video on TikTok 2022?

Whether you are using TikTok on an iPhone or Android phone, you can use CapCut to trim a video for TikTok with ease. Step 1: Go to App Store or Google Play to free install the video trimmer on your device. Open CapCut, tap on the new project, and then load the video you want to cut into the app.

Can’t stitch more than 5 seconds on TikTok?

What is this? You’ll be able to take a video on TikTok and give it a new ending. However, you can only Stitch up to five seconds of any individual video. A TikTok Stitch attributes the original content creator so no one can claim the clip as their own.

Can you only stitch 5 seconds?

You can trim the clip how you like but you can only select up to five seconds from the video.


Mir Tour's point of view on the subject of corona vaccination

It has been a good two years in which the corona pandemic has repeatedly imposed restrictions on our society and us travellers. We at Mir Tours are very happy about the general vaccination offer and wish/hope that sometime in spring 2022 the worst will be behind us and we can travel in all directions again.

In the few months that we were able to go on tour in 2020 and 2021, we obviously learned a lot. Our attitude to the subject is based on this, and on the legal and travel regulations as well as scientific findings.

Since around late summer 2021 we have seen that full vaccination and appropriate boosters are necessary if we want to travel smoothly. In many countries, only fully vaccinated or boosted people are allowed to enter without quarantine. These 5-14 days can rarely be included in the travel plan. In Western European countries, where you don't have to fear border controls, a digital vaccination certificate, usually with a booster, is required to be able to visit a restaurant, café or museum.

Increasingly, there are inquiries from interested parties and participants: "I hope you only take vaccinated people on tour!?"

This is how we come to the interpersonal and the risk of bringing the unvaccinated into a travel group. Scientific studies show that unvaccinated people become infected faster and pass on the virus twice as long as vaccinated infected people. Does that mean a separate taxi for the unvaccinated because no one wants to ride with them? A side table while eating? That harbours the potential for conflict.

In general, when we travel, we say that everyone can join us. However, we are currently excluding those who have voluntarily not been vaccinated from participating in a trip.

We are open to people who have not been vaccinated involuntarily, provided that the logistics on site allow it and they can show a doctor's certificate. This group currently makes up 2% of the participants. An example is Mr. B. He has a medical exemption, sometimes stays in the vehicle for a program item, is regularly tested and expects the okay from his doctor for an imminent vaccination that his body can tolerate. Because of the entry controls, he therefore prefers destinations within the Schengen area and Germany.

All booked persons will receive a Corona questionnaire from the booking department with the participant documents. In arranging and delivering the Services, we need to know that you can participate. It should also not happen again that an already small group loses participants because the unvaccinated are suddenly not allowed to enter the country, which then calls into question the economic viability of the trip.

Even before Corona, everyone who regularly travels long distances had to meet certain vaccination requirements. With well over 9 billion vaccinations, the safety and effectiveness of a vaccination against the corona virus is beyond question, especially since the possibility of a life-threatening course is prevented.

Stay healthy and protect yourself by vaccination, wearing a mask and keeping your distance.

Your Mir Tours Team


Cyanobacteria are a wide class of photosynthetic organisms that have been recently proposed as potential sources of materials (membranes, complexes) from which photoexcited electrons can be extracted to produce electrical current and renewable fuels1,2,3. Different species of cyanobacteria living in a wide range of habitats, were responsible for the original formation of the Earth’s oxygen enriched atmosphere, and continue to serve as a major source of primary production and oxygen evolution4. In cyanobacterial photosynthesis, the major photosynthetically relevant light absorbing pigment is chlorophyll (chl) a, which has maximal absorbance at 420–460 nm and 670–700 nm. The phycobilisome (PBS) antenna complex additionally absorbs between 550–680 nm. Photosystem I (PSI) also contains a minor antennae complex that has been shown to be red-shifted to ~710–730 nm5,6,7,8. The energy is efficiently transferred from the antennas to the Photosystem II (PSII) and PSI reaction centers (P680 and P700, respectively)9,10,11. In this light-driven process, electrons from water are sequentially transferred through a series of redox species to finally reduce NADP+ to be used for carbon fixation12,13 (Fig. 1). A proton-motive gradient is created between the thylakoid membrane lumen and the cytoplasm, resulting in proton-coupled electron transfer, which serves as the driving force for ATP production.

Fig. 1
figure 1

The electron flow of the photosynthetic process and respiration metabolism in cyanobacteria. The scheme was drawn based on the data described in references 12–21. Filled black arrows mark the respiration metabolism. Unfilled arrows indicate the photosynthetic and additional electron flow processes. Double arrows mark additional steps not shown for clarity. G3P is glyceraldehyde 3 phosphate, and TCA stands for tricarboxylic acid cycle. The membrane soluble plastoquinone (PQ) functions as an acceptor of residual electrons of the glycolysis and the TCA cycle, as well as an essential mediator of the photosynthetic electrons between PSII and the b6f complex. Dashed lines indicate the site of action of inhibitors of the photosynthetic or respiratory, used in this work

In the dark, cyanobacterial cells oxidize carbon sources via the respiratory system. For example, glucose is oxidized to acetyl CoA in the glycolytic process. Acetyl CoA is further oxidized in the tricarboxylic acid (TCA) cycle. These processes produce ATP, NADH, and FADH2. NADH and FADH2 are oxidized during oxidative phosphorylation to consume oxygen and produce CO2 and ATP14,15,16. Cyanobacteria lack the separation afforded by eukaryotic organelles, and it has been previously shown that electrons can flow between the photosynthetic and respiratory systems via redox active molecules17. For example, quinones from the photosynthetic plastoquinone (PQ) pool can oxidize NADH and FADH2, both products of glucose oxidation17,18,19,20,21 (Fig. 1).

Various attempts have been made to extract electrons from photosynthetic systems for the purpose of solar energy conversion (SEC)19,22,23,24,25,26,27,28,29. In some studies, isolated photosystems (PS) have been used within a bio-photoelectrochemical cell (BPEC) to produce electric power30,31,32,33,34. With isolated PS, an exogenous electron acceptor has to be used as a mediator (when utilizing PSI or bacterial reaction centers, an exogenous donor is also required) and the PS has to be fixed to the electrode, for instance by the presence of an immobilized mediator or a redox polymer24,25,31,34. In the case of PSII, water can serve as the electron donor, dependent on the stability of the oxygen evolving complex (OEC). One of the main problems with using isolated photosynthetic complexes for SEC is the relatively short lifetime of the biological components of the system, due to damage caused by radicals formed within the reaction centers35,36. Combined membrane systems have an evolutionary benefit for energy conversion that has recently been identified as a characteristic that could improve artificial photosynthetic SEC systems35. The use of living cells could mitigate this problem due to the presence of repair systems that can replace photo-damaged photosynthetic proteins. However, extracting electrons from living organisms is potentially more complicated as it may require an exogenous electron carrier (mediator) that can penetrate the cell wall and membrane, such as ferricyanide, cytochrome, or 2,6-dichloro-1,4-benzoquinone (DCBQ)23,27,36,37,38,39. To overcome this difficulty, cyanobacterial cells have been grown or dried on an electrode to extract an electric current by direct contact1,28,40,41. However, when such direct contact is utilized, the electric current is limited, as it will likely be generated from only a single layer of cells.

Here, we describe the construction of a BPEC in which live cyanobacteria produce a significant photocurrent that is derived from electrons of the respiratory and photosynthetic systems, without the need for exogenous electron donors or mediators. The resulting current was utilized for the production of molecular hydrogen on the cathode at a bias voltage of 0.65 V.

Results and Discussion

Production of a significant current by living cells

Cyanobacterial cells, Synechocystis sp. PCC 6803, were gently treated with a microfluidizer (herein called iSyn, see methods), and applied by gravity onto the graphite electrode. A platinum wire serves as the cathode while an Ag/AgCl/3 M NaCl electrode is used as a reference in all measurements (BPEC, Fig. 2a). When we measured current over time (chronoamperometry, CA), at an applied potential of 150 mV (vs. Ag/AgCl/3 M NaCl) (standard working potential obtained from the IV curve (Supplementary Fig. 1A), for all CA experiments unless mentioned otherwise), a dark current of 5 ± 1 µA cm−2 was obtained, probably directly from the respiratory system, as previously suggested36,37 (Fig. 2b, initial 100 seconds). Upon illumination, the current increased to the maximum stable current of 36 ± 4 µA cm−2. Accordingly, the net produced photocurrent was 31 ± 4 µA cm−2. Upon return to dark, there was a slow decline in the measured current. We noticed that the addition of the photosynthetic electron flow inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), resulted in a significantly faster increase in the photocurrent, reaching the maximum value in about 3 min, as compared to about 13 min in the absence of DCMU (Fig. 2b). Thus, DCMU was used for all electrochemical measurements unless mentioned otherwise. Cyclic voltammetry (CV) of the iSyn indicated the presence of a redox active species with an anodic peak at 50 mV (vs. Ag/AgCl/3 M NaCl) and a cathodic peak at −70 mV (vs. Ag/AgCl/3 M NaCl). The anodic current was significantly increased during illumination to present a quasi-reversible voltammogram, suggesting a photo-induced catalytic reaction mediated by a redox species (Fig. 2c). Optimization experiments show that increasing the amount of cells increases both CV (Supplementary Fig. 1B) and CA (Supplementary Fig. 1C) values up to a plateau of 150–225 μg chlorophyll. Since no external mediating electron transfer molecules were added to the BPEC, we conclude that the source of the redox species identified in Fig. 2c is from within the Syn cells. The characterization of this mediator will be described in detail below.

Fig. 2
figure 2

Gently treated Synechocystis cells generate an enhanced photocurrent using an endogenous redox mediator. a Schematic drawing of the bio photo-electrochemical apparatus with the iSyn settled on the working electrode (WE). The counter electrode (CE) is platinum, and the reference electrode (RE) an Ag/AgCl/3 M NaCl. All electrodes are connected to the potentiostat (P). b Chronoamperometric measurements at 150 mV (vs. Ag/AgCl/3 M NaCl) for iSyn in the presence (blue) or absence of DCMU (red). The yellow up arrow indicates light on (the initial 100 seconds show the dark current) and the black down arrow indicates light off. c Cyclic voltammograms of iSyn, illuminated (solid blue lines) or in the dark (dashed blue lines). Buffer lacking iSyn shows no redox activity (black solid line). Measurements recorded at a rate of 5 mV s−1

We noticed that there was a negative correlation between the pressure used during the treatment performed on the cells and the measured current (Fig. 3a). The highest current was obtained when the lowest possible pressure of the microfluidizer was used (Fig. 3b). Lower currents were obtained when using untreated cells (Syn) or cells that were osmotically shocked (OsSyn). Membrane fragments obtained from cells that were completely disrupted at higher pressure with a French Pressure cell (mSyn) did not produce measureable currents (Fig. 3a). The microfluidizer treatment (iSyn) resulted with a higher anodic peak in the dark, compared to OsSyn and Syn (Supplementary Fig. 1D), whereas membrane fragments did not show any anodic peak (Supplementary Fig. 1E) indicating the absence of the redox species (see methods for all preparations). iSyn appear to retain their cellular structure and remain clumped together as visualized by scanning electron microscopy (SEM) and florescent microscopy (Fig. 3c, Supplementary Fig. 2A, respectively). To further investigate the state of the iSyn preparation, we utilized confocal fluorescence microscopy. Syn, OsSyn, and iSyn appeared in the microscope to retain PBS functional integrity. Treatment of the same cells using higher pressures (mSyn) produces aggregated membranous material, lacking the PBSs (Supplementary Fig. 2A-C), which are soluble and spontaneously released from the membranes9. The major difference between the Syn and iSyn is that the latter are clumped together in large clusters (Fig. 3c, Supplementary Fig. 2A). In the OsSyn preparation, cells are seen to form smaller clusters of two or three cells with the same appearance of fusion (Supplementary Fig. 2A). To determined cell viability, we prepared cells as described above, and illuminated them for 30 min in the BPEC under standard conditions. We then removed the iSyn from the BPEC by simple washing. The growth rate of the iSyn was then compared to the growth rates of either untreated Syn or non-illuminated iSyn in new growth media. All cells had similar growth rates (Fig. 3d and Supplementary Fig. 3a). To further determine cell viability, we performed a colony formation test (Supplementary Fig. 3B). We applied an amount of Syn, iSyn, or membranes (mSyn) containing the same amount of chlorophyll onto a growth plate, and followed the growth of the colonies. Syn and iSyn grow at a similar rate, 364 ± 98 and 280 ± 68 colonies per femtograms of Chl a to Syn and iSyn, respectively, whereas mSyn contains much smaller amount of living cells (11 ± 3). These results indicate that the application of mild pressure did not harm the ability of Synechocystis cells to multiply and divide. iSyn were also shown to photosynthetically evolve O2 at a similar rate to Syn cells (O2 evolution of 392 ± 53, 464 ± 60 nmol O2 µg chl−1 h−1 for iSyn and Syn, respectively). We thus suggest that iSyn are living, yet modified and/or clustered cells and that the change that occurs to the cells does not modify the biological energy transducing systems.

Fig. 3
figure 3

iSyn are living, modified, and clustered cells. a CA measurements of Synechocystis cells (Syn, green), cells undergone a mild osmotic shock treatment, (OsSyn, Orange), cells undergone a gentle pressure treatment (iSyn, blue), and thylakoid membranes (mSyn, red). b CA measurements of cell undergone treatment with microfluidizer at 0, 15, 30, and 95 psi, as indicated in the figure. c SEM image of iSyn (right) and Syn (left) on graphite. Scale bars are 2 μm. d Growth curve of Syn (green), iSyn (black) and iSyn that were illuminated for 30 min in the BEPC (blue) in liquid medium. The vertical lines show the standard deviation (= 5)

The combined activity of two pathways generates the current

The photocurrent in the presence of DCMU could be explained by two alternative pathways. In the first one, the electrons are derived from water oxidation and are transferred to putative endogenous mediator(s) prior to QB, before the binding site of DCMU at QB, similar to the electron transfer from PSII to silicomolybdate42,43. The second possibility is that DCMU inhibits the activity of PSII, including the water oxidation complex. In such a case, a light-driven electron source must be located further downstream of the QB site, and could involve the PQ pool, cytochrome b 6 f, and finally PSI, as the site of photoactivity. A stable photocurrent that is not a result of PSII activity can only exist if there is an alternative source of electrons to PSI. Such a possible source could be the respiratory system that is linked to the photosynthetic apparatus in cyanobacteria14,17,18,19,20,21 (Fig. 1). To differentiate between these possibilities we repeated the electrochemical experiments with a non-autotrophic mutant of Synechocystis sp. PCC 6803, where the psbA genes (encoding the D1 protein) have been deleted, thus leading to a non-functional PSII (ΔpsbA)43,44 (Supplementary Fig. 4A). CA measurements displayed a photocurrent that is similar to that obtained with iSyn (Fig. 4a). Moreover, the iSynΔpsbA cells look similar to iSyn cells (Supplementary Fig. 4B) and require the same preparation for optimal photocurrent as iSyn does (Supplementary Fig. 4B-D). The iSynΔpsbA cells also contain the same redox mediator (Supplementary Fig. 4D). Another proof of the lack of involvement of PSII in the electron transfer pathway in the BPEC was to inactivate the OEC of PSII by incubation with Tris buffer. In the Tris treated iSyn similar photocurrents were obtained (Supplementary Fig. 5A-B). Taken together these results indicate that the electron path is from the respiratory system, through PSI and to the electrode.

Fig. 4
figure 4

iSyn photocurrent to the BPEC involves both photosynthetic and respiratory systems. a CA measurements for iSynΔpsbA. b Action spectra: the obtained photocurrent was normalized to the photon energy input (external quantum efficiency) at different wavelengths. The external quantum efficiency of iSyn is shown in blue and that of iSynΔpsbA in red. A new measurement with fresh cells was used for each wavelength. c CA measurements for iSynΔpsbA without (red) and with (green) the addition of iodoacetate and in the presence (full line) or absence (dashed line) of glucose. d CA measurements for iSyn without (blue) and with (green) the addition of iodoacetate or in the presence (full line) or absence (dashed line) of glucose in the buffer

To further support the notion that the photosystem deriving the photocurrent is PSI and not PSII, we measured the action spectrum of the photocurrent production. To this end, we measured the photocurrent as a function of the wavelength and calculated the external quantum efficiency (EQE) at each wavelength (Fig. 4b). The EQE in both iSyn and iSynΔpsbA was evident at all wavelengths of visible light with an increase at 700 nm suggesting the importance of the participation of PSI in the activity. Together, these results demonstrated that PSI and not PSII is the photosystem that drives the photocurrent when iSyn cells are illuminated in the BPEC.

As already indicated above, the lack of the water oxidation activity of PSII in the iSynΔpsbA indicates that there must be an alternative electron donor. Studies suggest that electron transfer between the respiratory system and the photosynthetic system may occur via the plastoquinone (PQ) pool14,18. To investigate this, we performed experiments in the presence of glucose. Glucose is known to be uptaken by Synechocystis cells, providing energy for growth in the dark or for growth of non-photosynthetic mutants43,44. Addition of glucose significantly extended the period of the production of the highest current (Fig. 4c). Furthermore, iodoacetate, which blocks the respiratory path at the site of glyceraldehyde-3-phosphosphate dehydrogenase activity (Fig. 1), significantly inhibited the photocurrent (Fig. 4c), supporting the suggestion that the respiratory system is the main electron donor.

The above measurements support our hypothesis that under these conditions a respiratory-PSI electron transfer pathway exists in the ΔpsbA mutant. In a fashion similar to that seen for iSynΔpsbA, iSyn also exhibits extended photocurrent lifetime in the presence of glucose (Fig. 4d and Supplementary Fig. 5C-D), and the photocurrent is decreased in the presence of iodoacetate (Fig. 4d), reaffirming that the major electron source is the respiratory system. Together, the results so far uncover an electron transfer pathway in which electrons derived from the respiratory pathway reduce PSI that can further photo-reduce the electrode in the gently treated Synechocystis live cells.

The mediator is a small diffusive soluble molecule

Electrochemical experiments show a slow increase and slower decline in the photocurrent (Fig. 2b). Moreover, the potential difference between the anodic and cathodic peaks in the voltammogram (Fig. 2c) suggests that the current in the BPEC is mediated by a diffusive soluble molecule. Cyanobacterial cells contain both small redox active proteins, as well as metabolites that undergo redox reactions. We introduced a single layer synthetic membrane with a nominal molecular weight cut-off of 3 kD between the iSyn and the electrode (Fig. 5a) and performed CV measurements under light. These show the same anodic and cathodic peaks in the presence of iSyn as without the membrane, suggesting the mediator can diffuse through a 3-kD membrane and is thus most likely not a protein.

Fig. 5
figure 5

iSyn electron transfer to the BPEC is via a diffusive endogenous mediator. a CV in the light for buffer (black) and the iSyn (blue) separated by a 3 kD dialysis membrane on the graphite electrode. b CV of supernatant fraction from centrifuged iSyn cells separated by filtration through 3 kD cut-off centricon. Filtrate (solid blue line), retentate (dashed blue), and buffer (black). c Illustration of the scanning electrochemical microscopy setup. iSyn settled on the working electrode (WE) electrode. The counter electrode (CE) is platinum, and the reference electrode (RE) a Ag/AgCl/3 M KCl. The tip is a carbon-based microelectrode with a mixture of bilirubin oxidase (BOD) embedded in an Os-complex modified polymer matrix. All electrodes are connected to the bipotentiostat. d CA of the iSyn (blue) and the BOD tip current (red) measuring the oxidation of the mediator at a distance of 30 µm from the graphite electrode

To further isolate the mediator, iSyn were illuminated followed by centrifugation. The supernatant was then filtered through a 3 kD ultrafiltration device and CV measurements were performed on both the filtrate and retentate. These measurements show that only the filtrate contains a redox active species while the retentate has no redox active component (Fig. 5b). This indicates that the mediator is a water-soluble molecule that passes through the 3-kD filter. Similar experiments performed on dark exposed iSyn (Supplementary Fig. 6A) showed the presence of a redox peak but with a smaller area, suggesting that illumination increases the release of the mediator from the cells. In addition, the redox behavior of the mediator is inactivated after 10 min incubation at 60 °C (Supplementary Fig. 6B). We suggest that the redox molecules could be a soluble quinone, a flavonoid44,45 or a small peptide that is temperature sensitive.

Scanning electrochemical microscopy (SECM) was used to exclude the possible release of O2 under irradiation and proved the existence of a soluble mediator in accordance with the CA measurements. SECM measures the local current on a microelectrode tip precisely positioned above the evaluated sample. SECM can be used to measure local electrochemical reactions over an evaluated sample or to efficiently collect reaction products with the tip placed in close proximity to the analyzed surface, for example, it was previously used to measure oxygen production by n-type semiconductor-based photo-anodes for water splitting45,46. The SECM experiment was performed by placing the tip microelectrode above the center of the cells at ~30 µm from the graphite electrode surface with iSyn deposited on top (Fig. 5c). As SECM probe we used a carbon-based microelectrode modified with bilirubin oxidase (BOD) embedded in an Os-complex modified polymer matrix47,48. The electrode was polarized at 0 mV (vs. Ag/AgCl/3 M KCl) for the steady-state reduction of O2. To decrease the background current related with the reduction of O2 naturally present in solution, Ar was bubbled into the buffer for 15 min before the measurement and continuously, gently, bubbled during the measurement. The obtained results in the SECM measurements clearly demonstrate the absence of any cathodic current related to the collection of O2 evolved from the sample. Furthermore, a considerable shift in the recorded current at the microelectrode toward more positive values was observed under irradiation and following a clear correlation between the sample current and the tip current under dark and light conditions (Fig. 5d). The shift in current at the SECM probe can then be attributed to the oxidation of the soluble mediator at the tip microelectrode that is polarized at a more negative potential than the redox peak observed for the mediator in previous experiments (Fig. 2c). Further measurements at a tip potential of −200 mV (vs. Ag/AgCl/3 M KCl) indicate a reduction of the mediator in the light (Supplementary Fig. 6C). SECM measurements confirmed that the mediator diffuses from the iSyn through the solution to the tip. Thus, we can conclude that there is a water-soluble electron carrier that mediates between the iSyn and the electrode.

Finally, in an attempt to identify the electron carrier mediator if it is a metabolite, we carried out a metabolic profiling49,50 of Syn, iSyn, and iSyn that were illuminated in the BEPC. No significant change between the different samples profile was detected, suggesting that the gentle treatment does not cause a significant change in the amount of a metabolite but rather the release of the mediator to the medium or the outrace of the cells (Supplementary Fig. 7 and Supplementary Table 2).

DCMU has a unique effect in the iSyn BPEC

In the presence of DCMU, the maximum current is reached faster and the current is slightly enhanced (Fig. 2b, Supplementary Fig. 8A,B). However, the photocurrent lifetime is prolonged by the presence of added glucose in either the presence or absence of DCMU (Supplementary Fig. 8C), suggesting that DCMU affects the electron flow but not the stability of the photocurrent. Counter-intuitively, the presence of DCMU was found to be crucial for the photocurrent production by the iSynΔpsbA, since in the absence of DCMU the photocurrent drops to 14% of the photocurrent obtained in the presence of DCMU (Supplementary Fig. 8B,D). Thus, even though iSynΔpsbA lacks the well-studied PSII-binding-site of DCMU, the addition of the herbicide has a dramatic effect and actually was essential for the production of the 20–30 µA cm−2 current obtained with iSynΔpsbA even without DCMU (Supplementary Fig. 8D). The effect of DCMU in the iSynΔpsbA strongly indicates that DCMU has secondary binding sites with Synechocystis cells that have not yet been characterized. Moreover, DCMU increase the release of the mediator (Supplementary Fig. 8E) and as a results increases the photocurrent and decreases the time it takes to reach the maximum photocurrent (Fig. 2b, Supplementary Fig. 8C). Our results suggest that DCMU affects the production of the photocurrent in both iSyn and iSynΔpsbA at secondary site(s) by either inhibiting forward electron flow within the respiratory system, or by enhancing the release of the mediator.

Hydrogen is produced in the BPEC

As no external redox components were added to the BPEC, we presumed that protons are reduced to molecular hydrogen at the Pt cathode. To measure hydrogen production, we built a gas-tight BPEC connected directly to a gas-chromatograph (GC) (Fig. 6a). The gas actively diffuses via ducts and is pumped into the GC, hence there is a short delay in the gas measurement. Figure 6b shows the H2(g) production over time measured using this configuration applying a voltage of 650 mV between the anode and cathode. The lack of H2(g) production in the absence of light and/or iSyn (Supplementary Table 1) indicates a correlation between the light-current and the H2 production. During the 2 h of illumination an average of 3.5 µmol H2(g) mg Chl−1 h−1 is produced at a Faradaic efficiency of ca. 36%. The low Faradaic efficiency is most likely the result of molecular oxygen in the buffer, indicated by higher Faradaic efficiency in the absence of oxygen (Supplementary Fig. 9), or the mediator reduced on the cathode in addition to proton reduction.

Fig. 6
figure 6

Hydrogen is evolved on the cathode at a lower voltage than in water electrolysis. a Schematic drawing of the working setup for the hydrogen evolution measurements. The CA was measured at 50 mV (vs. Ag/AgCl/3 M NaCl) which corresponds to a voltage of 650 mV between the anode and cathode. b Simultaneous CA measurement of photocurrent (blue) and GC measurement of hydrogen production (red) measured as a function of time for the iSyn at 50 mV (vs. Ag/AgCl/3 M NaCl). c Schematic drawing of the electron flow from carbohydrates (internal or external) via the respiratory, light-driven activity of PSI, and an endogenous diffusive mediator to form hydrogen gas. The multiple electron transfer steps between the PQ and PSI are shown for simplicity as multiple curved arrows

In this study, we show light-driven current and hydrogen production with mildly treated live Synechocystis sp. PCC 6803 on a graphite electrode. The simple treatment makes the electron transfer possible from the cells to the electrode. This is the first time CV measurements indicate the existence of an endogenous mediator that can exit the cells’ membranes in mildly treated live cyanobacteria50,51. The electron extraction, by the intrinsic mediator, is photo-driven by PSI (Fig. 6c) that is reduced by the respiratory system, explaining the enhancing effect of glucose addition. In the absence of externally added glucose, the current originates from the internal carbohydrate pool produced during the growth phase. Whether PSI reduces the mediator directly or through other components of the photosynthetic electron transfer chain has not yet been ascertained. It is important to note that current is obtained from non-treated cells as well, however at much lower rates. This reiterates that the role of the treatment is to augment the amount of released mediator, and not the inducing of any modification to either of the two biological systems. During the review process of this article, a manuscript suggesting mediator dependent electron transfer in cyanobacteria was published.52,53 In this work, porous translucent electrodes were used in a BEPC cell containing Synechocystis cells to obtain electric currents that were higher than obtained in nonporous electrodes but significantly lower than reported in this work using iSyn and graphite electrode.

The use of iSyn instead of thylakoids may have the potential to utilize physiological repair mechanisms during the operation of the BPEC. This system, based on live Synechocystis and an endogenous mediator, can further be used to study extraction of electrons from live cells and with some future modifications can be used to generate photocurrent for a long time by cell rejuvenation.

In the recent past, utilization of biological systems for environmentally clean energy production has been offered as an attractive alternative to the use of fossil fuels. Our results presented here show that Cyanobacteria offer a unique opportunity to fully utilize the potential of biological energy conversion systems. We have shown here that in these live cells, electrons released during the reactions of the respiratory system can be “pumped” back to higher energy by the photosynthetic system, enabling both sustained current and the reduction of hydrogen at lower added bias. Indeed, coupled with other innovative uses of the solar spectrum24 we believe that the cyanobacterial system can serve a true paradigm for clean bio-energy production.

Preparation of mildly treated cells of Synechocystis

Cells of a late log phase culture (OD750 = 1.0–1.5) that was grown as previously described in Larom et al.38,39 were centrifuged for 10 min at 15,200× g in a SLA-1500 rotor and resuspended in Buffer A (20 mM Tris pH 8, 400 mM NaCl and 15 mM MgCl2). The cells were then passed twice through a microfluidizer (Microfluidics Corporation) under a pressure of 10–15 psi. The cells were centrifuged for 20 min at 27,660× g and the cell pellet was resuspended in 100 mM phosphate buffer (pH 6). The final concentration of chl a was determined in 80% (v/v) acetone according to Arnon53,54. The final chlorophyll concentration of all samples was 0.6–1.3 mg chl ml−1.

Preparation of all other Synechocystis samples

Thylakoid membranes (mSyn) were isolated in a fashion similar to the iSyn preparation; however, a French pressure cell (Sim Aminco Spectronic Instruments) operating at 1500 psi was used instead of the microfluidizer, followed by centrifugation for 2 min at 600× g in order to pellet unbroken cells and 20 min centrifugation at 27,660× g to pellet the thylakoids. For mSynΔpsbA preparation, we used the microfluidizer at high pressure of 90 psi circulating for 28 pulses. Untreated cells (Syn) were pelleted and resuspended in phosphat buffer (pH 6). Osmotic shocked cells (OsSyn) were resuspended in buffer A and pelleted after 20 min and resuspended in phosphate buffer (pH 6). The cells treated with different pressures were prepared similar to iSyn, but under higher pressure in the microfluidizer step. The final concentration of all samples was 0.6–1.3 mg chl ml−1.

Electrochemical measurements

Electrochemical measurements were performed either at the Solar Simulation Lab (Viterbi Faculty of Electrical Engineering, Technion) using a Zennium electrochemical workstation (Zahner Elektrik) and a solar simulator light source (Oriel Sol3A), or at the Hydrogen Lab (Grand Technion Energy Program) with an nStat multichannel potentiostat (Ivium) and a Xenon lamp solar simulator (Abet). For some measurements, we used a Palmsens3 (Palmsens) potentiostat and A1 light line (Sciencetech). All measurements were carried out in a three electrodes configuration under the illumination of one solar unit (1SU). Graphite (Graphite Store, pn#bl001230) was used as a working electrode, a Pt electrode (ALS) served as the counter electrode and a Ag/AgCl/3 M NaCl as a reference electrode (ALS). For each measurement, a sample containing 150 µg of chl a was placed on the 1.8 cm diameter graphite electrode. The sample was not stirred or replaced during the measurement. The medium was phosphate buffer (100 mM phosphate, pH 6) containing 100 mM NaCl. When indicated, 150 µM of DCMU was added. For the ΔpsbA mutant, chlorophyll amount of 50 µg was used. For the relevant electrochemical measurements, 6 mM of D-glucose in the absence or presence of 5 mM iodoacetic acid (sodium salt) were added.

Quantum efficiency measurements

The EQE of the BPEC containing iSyn (150 µg chl) was measured at a potential of 150 mV (vs. Ag/AgCl/3 M NaCl). The iSyn cells were illuminated with monochromatic light obtained by coupling a white light source to a monochromator (Cornerstone CS260) with a spectral bandwidth of 10 nm. Fresh cells were used in each measurement, and the maximum photocurrent was recorded. The photon flux was obtained from the light intensity measured by a power meter (918D High Performance Photodiode Sensor), and the EQE was calculated according to equation 1:

$${\rm EQE} = \frac{{{\mathrm{Maximum}}\,{\mathrm{photocurrent}}\,/\,q}}{{{\mathrm{Photon}}\,{\mathrm{flux}}}}$$

where q is the electron charge.

When analyzing iSynΔpsbA we used 50 µg chl for each measurement and the bandwidth was 20 nm.

Oxygen evolution measurements

For measurement the photosynthetic activity by analyzing the rate of oxygen evolution, the cells (10 µg chl a) were placed in phosphate buffer (pH 6) in a final volume of 1 ml. A volume of 3 mM 2,6-dichloro-1,4-benzoquinone (DCBQ) was used as an electron acceptor and oxygen evolution was determined using a Clark-type electrode (Hansatech). Following preincubation in the dark for 2 min, the cells were illuminated with a white light halogen projector lamp (MRC) for 1 min and the increase in oxygen concentration was digitally measured.

Gas chromatography experiments

Hydrogen measurements were performed in the Hydrogen Lab (Grad Technion Energy Program) using an Agilent 7890 A GC system (Agilent technologies) with a molsieve 5 Å column, 10 ft*1/8”*2 mm (Agilent technologies) to determine H2 production. Gas from the BPEC was continuously pumped to the GC. The applied potential on the working electrode was 50 mV (vs. Ag/AgCl/3 M NaCl). The bias between the anode and cathode measured by a voltmeter (m832, Mastech) was 650 mV. Calibration was performed by measuring known amounts of hydrogen directly injected to the GC.

Scanning electron microscopy

The morphology of cellular samples was characterized by high-resolution scanning electron microscopy (SEM) (Ultra PLUS, Zeiss). Further experimental details are found in the figure legend.

Purification of the mediator

iSyn cells, correspond to 400 µg chlorophyll from the stock solution, were illuminated for 5 min (without DCMU) in a 1.5 ml tube and then centrifuged (5417 R, Eppendorf) for 1 min at max speed. The supernatant was collected, the pellet was resuspended in 250 µl Phosphate buffer, centrifuged again, and the supernatant was collected. Filtration was performed using 3 kD (Vivaspin 500, Sartorius Stedim biotech) and centrifugation (5417 R, Eppendorf) for 1 h at 14,000× g. Heat inactivation was performed in a block heater (SKS Biomedical instruments) at 60 °C for 10 min.

Scanning electrochemical microscopy

SECM experiments were performed using a Ag/AgCl/3 M KCl double junction reference electrode, a Pt cylindrical mesh as counter electrode, and a BOD modified carbon microelectrode as electrochemical probe. The BOD modified tip was fabricated following a previously reported procedure54,55 by modifying a carbon-based microelectrode with a mixture of BOD embedded in an Os-complex modified polymer matrix47,48. The SECM setup is schematically shown in Fig. 5c and is based on a previously described system46,47 consisting of three stepmotor driven micrometer screws (Owis) for positioning of the SECM tip in x-, y-, and z-directions, a bipotentiostat (PGU-BI 100, Jaissle), and a control software programmed using Visual Basic 6.0. A 150 W Hg–Xe lamp (LC8, Hamamatsu photonics) was used for irradiation of the sample at an incident light intensity of 55 mW cm−2 (visible light). The sample was placed in a Teflon SECM cell sealed with an O-ring exposing an area of about 0.385 cm2. The tip was positioned in close proximity (~30 µm) to the analyzed sample by recording z-approach curves in air-saturated buffer before adding the iSyn. The BOD modified tip was polarized at 0 or - 200 mV (vs. Ag/AgCl/3 M KCl). During the measurement, a given potential of 150 mV (vs. Ag/AgCl/3 M KCl) was applied to the sample. Both the tip and sample current were recorded during light and dark periods. For the SECM measurements, we used frozen/thawed iSyn cells. After preparation of the cells as described above, dimethyl sulfoxide was added to the cells, prior to flash-freezing in liquid nitrogen. iSyn was later thawed on ice and used for the SECM experiments.

Procedures for PBS spectroscopic measurements, confocal imaging, Tris treatment, colony formation test, and metablomics profiling were detailed in Supplementary Methods.

Data availability

All data presented in this paper can be obtained from the corresponding authors upon reasonable request.