1961 Volume 7 Issue 3 Pages 145-154
1. Lysine accumulation by various auxotrophs was found. Especially a large quantity of lysine was accumulated by homoserine-less mutant of glutamic acid producer, previously named Micrococcus glutamicus. All homoserine-less mutants tested including Bacillus subtilis and E. coli showed lysine accumulation. Considerable lysine accumulation occurred with mutants such as threonine-less, isoleucine-less, leucine-less and both isoleucine and leucine-less mutants.
2. Lysine accumulation by homoserine-less mutant of M. glutamicus was studied rather in detail. Lactic acid accumulated in place of lysine in excess of homoserine or threonine and biotin in media. In sufficient concentration of biotin and a proper amount of requiring amino acids, lysine accumulated. In low biotin concentration the tendency of glutamic acid accumulation was recognized.
3. Homoserine and threonine inhibited specifically the lysine accumulation from glucose and ammonia by washed cell suspension of homoserine-less mutant of M. glutamicus. The action of these amino acids was suggested to he inhibition of enzyme action rather than enzyme formation.