Artturi Ilmari Virtanen (1895-1973) was awarded the 1945 Nobel Prize in Chemistry for his research and inventions in agricultural and nutrition chemistry, especially for his fodder preservation method. The method, patented in 1932, was a kind of silage â€“ fodder converted into moist and juicy livestock feed by anaerobic acid fermentation -- that improved the storage of green fodder. The process included adding dilute hydrochloric or sulfuric acid to newly-stored grain, which stops harmful fermentation. He also isolated numerous compounds from fodder plants, including new amino acids and organic sulfur compounds, many of which proved to be important for the nutrition of man and domestic animals. Virtanen also established the necessary role of cozymase â€“ the active component of zymase, a yeast enzyme that makes sugar ferment -- in lactic and propionic acid fermentations and in sugar phosphorylation. He elucidated the first bacterial sugar fermentation involving the conversion of dioxyacetone to glycerol and glyceric acid in the presence of phosphates. Virtanen also investigated the biological mechanisms of nitrogen fixation in the root nodules of leguminous plants. He showed that the red pigment leghemoglobin was a key component of fixation. The asteroid 1449 Virtanen, discovered by renowned Finnish astronomer and physicist YrjÃ¶ VÃ¤isÃ¤lÃ¤, was named after Virtanen.