BIOTIN BIOSYNTHESIS. I. BIOTIN YIELDS AND BIOTIN VITAMERS IN CULTURES OF PHYCOMYCES BLAKESLEEANUS.

Eisenberg, M. A. (Columbia University, New York, N.Y.). Biotin biosynthesis. I. Biotin yields and biotin vitamers in cultures of Phycomyces blakesleeanus. J. Bacteriol. 86:673-680. 1963.-The addition of pimelic acid to a well-aerated medium resulted in a 10- to 12-fold increase in the biotin production of Phycomyces blakesleeanus. Azelaic acid also stimulated biotin production, but not to the same extent as did pimelic acid. A number of biotin analogues were found to be inactive. Further enhancement of the biotin yield could not be attained by replacing glucose and aspargine by other carbon and nitrogen sources. Replacement cultures, however, proved to be equally as effective as growing cultures under the same conditions. The omission of trace elements reduced the growth and biotin production. The "true" biotin was affected to a greater extent than the "total" biotin. Zinc and iron proved to be the essential trace metals. In the absence of zinc, both the growth and the total biotin production were markedly reduced. The omission of iron affected primarily the biotin production. P. blakesleeanus produces biotin, desthiobiotin, biotin-d-sulfoxide, biocytin, and an unknown biotin vitamer. The latter has been identified as an amino acid by electrophoretic analysis. It is avidin-uncombinable, and does not support the growth of Lactobacillus arabinosus (L. plantarum) or Neurospora crassa.