Three separate systems were used to pulse glucose to starved E. coli. The spin flask system (i) and plate reader system (ii) provided glucose pulses at defined frequencies. In the real-time metabolomics configuration (Link et al, 2015), another pump circulated culture and injected 2 µL of culture directly into a time of flight (QTOF) mass spectrometer every 10-15 s from the spin flask system. A microfluidic platform (iii) reproduced the pulse feeding and tracked division events. A pulsing period is defined as the time between the start of successive glucose medium exposures. During each pulse, glucose medium was flowed for 10 seconds, and the no glucose buffer was flowed in the intervening period 