Comparative microbiological assays of members of the vitamin B complex in yeast and liver extracts

Abstract
The requirements of several spp. of yeasts for 7 members of the vit. B complex were investigated. Several spp. failed to grow appreciably in absence of one or more of these factors, while Kloeckera brevis required 6 of them for growth. The vit. B contents of a number of yeast and liver extracts were estimated by measuring growth responses of several yeasts and the results were compared with those of published microbiologic methods of assay. K. brevis was found satisfactory for assay of pantothenic acid and inositol; Saccharomyces cerevisiae var. ellipsoidesis for pantothenic acid; S. macedoniensis for aneurin; Candida guillermondia for biotin; and Schizosaccharomyces pombe for inositol. A''. brevis was used for assay of pyridoxin but the results were frequently at variance with those given by Neurospora sitophila.