Pfizer Handbook of Microbial Metabolites 306 



oxytetracycline (Streptomyces rimosiis).-^ The structures of 

 certain other unusual amino acids are listed in this section. 



Production of glutamic acid by streptomycetes on synthetic 

 medium containing glycine has been investigated.-' Yields of 

 extracellular glutamic acid were 0.25-1.75 g. per liter. It was 

 the only amino acid or nitrogenous material present after four 

 and seven days, but after ten days some alanine, phenylalanine, 

 aspartic acid and glycine appeared. Strains examined were: 

 Streptomyces anmilatus, S. aureofaciens, S. fradiae, S. olivaceus 

 and S. rimosus. 



The high proportions and amounts of L-glutamic acid syn- 

 thesized by microorganisms have led to the development of an 

 economical process for its commercial production. Certain mi- 

 crococcus and bacillus species produce more than a 20% yield 

 (molar basis) from the glucose supplied.-^ A similar yield of 

 valine has been reported.-"' 



L-Lysine is also produced commercially by a direct process 

 (micrococcus, bacillus)-'* and by a two-stage process (Escher- 

 ichia coli, Aerobacter aerogenes),-' 2,6-diaminopimelic acid be- 

 ing the intermediate in the latter case. 



Tryptophan production by E. coli and by Salmonella typhi has 

 been reported as small unless indole is added.-'' The indole 

 apparently competitively inhibited tryptophanase. Many mi- 

 croorganisms are able to synthesize tryptophan from indole and 

 serine. 



A survey of 20 genera, 72 species and 334 strains of aerobic 

 bacteria for amino acid accumulation revealed no marked tax- 

 onomic difference except that facultative aerobes such as escher- 

 ichia, aerobacter and bacillus species were superior to obligatory 

 aerobes such, as pseudomonas. Production and accumulation 

 were more dependent on strain and conditions.-" 



The biosynthesis and metabolic interrelationships of amino 

 acids can be considered here only in briefest summary because 

 of the breadth and complexity of the subject. More thorough re- 



22 F. A. Hochstein, /. Org. Chem. 24 679 (1959). 



23 D. Perlman and E. O'Brien, /. Bad. 75 611 (1958). 



-^ Toshinobu Asai, Ko Aida and Kunio Oishi, Bull. Agr. Chem. Soc. 

 (Japan) 21 134 (1957). 



25 Zenjiro Sugisaki, Nippon Nogei-kagakii Kaishi -54 153 (1960). 



2" Shukuo Kinoshita, Kiyoshi Nakayama and Sohei Kitada, J. Gen. 

 Appl. Microbiol. 4 128 (1958). 



27 Lester E. Caslda, Jr., U. S. Patent 2,711,396 (1956). 



2sp. Fildes, J. Gen. Microbiol. 15 636 (1956). 



2" Hiroshi lizuka and Kazuo Komagata, Nippon Nogei-kagashu 

 Kaishi 34 27 (1960). 



