The Influence of Amino Acids and Proteins on Nitrogen Fixation by Azotobacter Chroococcum

Microbiology of Soil

“…Alcoholic yeast extract (0.5 to 7 per cent) was found by Schroeder (59) to increase growth in pro portion to the amount of the extract used. Greaves et al (60) added tyrosine, DL-isoleucine, hydroxyproline, and L-histidine to synthetic mannitol base medium and obtained greatly increased fixation of nitrogen by A. chroococcum. Casein and albumin acted similarly but gelatin decreased the fixation.…”