%0 Journal Article %A Woiwod, A. J. %A Proom, H. %T Identification of Characteristic Extracellular Ninhydrin-Positive Substances Produced by some Bacteria %D 1950 %J Microbiology, %V 4 %N 3 %P 501-507 %@ 1465-2080 %R https://doi.org/10.1099/00221287-4-3-501 %I Microbiology Society, %X SUMMARY: When certain species of bacteria are grown in an acid-hydrolysate of casein medium, ninhydrin-positive substances which were not present in the un-inoculated medium appear on chromatograms of the culture filtrates. Shigella paradysenteriae and Escherichia coli produce γ-aminobutyric acid by decarboxy-lation of glutamic acid. The substance produced by Serratia marcesens resists acid hydrolysis, gives a positive Sakaguchi reaction and matches arginine on two-dimensional chromatography. The substances produced by Clostridium sporogenes, Cl. bifermentans and Cl. sordellii, but not by any of the other species of Clostridia examined, are δ-aminopentanoic acid, probably derived from proline, and α- and γ-aminobutyric acids produced by unknown mechanisms. Proteus vulgaris and Clostridium tetani each produce two polypeptides containing a high proportion of amino-acids in the groups valine/methionine and leucine/isoleucine. These two pairs of polypeptides are similar in R F value and gross amino-acid composition. Staphylococcus aureus produces α-aminobutyric acid which may be derived from threonine. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-4-3-501