SummaryThe growth requirement or growth-promoting effect of biotin-vitamers on bacteria and yeasts was investigated. Biotin, dethiobiotin and biocytin (N-e-biotinyl-L-lysine) were shown to be required for growth in a number of bacteria and yeasts. The biological activity of dethiobiotin was relatively higher than that of biotin, but was negative for lactic acid bacteria. Biocytin had high activity for Bacillus subtilis (natto), Debaryomyces japonicus and Hansenula capsulate. The biotin activity of 7-keto-8-aminopelargonic and 7,8-diaminopelargonic acids was low or negligible for bacteria but relatively high for yeasts such as the genera of Endomyces, Endomycopsis and Saccharomyces. Pimelic, pelargonic and pelargonylhydroxamic acids had no growth requirement fo r or growth-promoting effect on any of the bacteria or yeasts tested.

The biosynthesis of biotin-vitamers from various carbon sources by the members of the Enterobacteriaceae as one of the groups of intestinal bacteria was investigated. The biotin-vitamers synthesized in each case included one or more of dethiobiotin (main product), 7-keto-8-aminopelargonic acid, and biotin. True biotin was shown to be syn thesized under aerobic conditions but not under anaerobic conditions by each of several strains belonging to one of the genera, Erwinia, Escheri chia, Proteus, and Serratia, and using culture media containing one of galactose, peptone, Polypepton, or casamino acid. In addition, a biotin precursor, pimelic acid, was also synthesized by several bacteria utilizing carbon sources such as maltose, mannose, galactose, peptone, or casamino acid.