AN UNIFORM MEDIUM FOR MICROBIOLOGICAL DETERMINATION OF THE B-VITAMINS WITH VARIOUS LACTIC ACID BACTERIA

Abstract

A single medium uniformly available for microbiological assay of the B-vitamins with various lactic acid bacteria was described. Test organisms used are as indicated in Table 1 and the constituents of the medium are as listed in Table 2. For use in assays, the appropriate vitamin is omitted from the medium. It has been shown that this medium is applicable to the assays of 11 varieties of B-vitamins with good responses which compare favorably with those obtained by using the assay medium previously reported. The medium was quite transparent even after heat sterilization, and the double strength medium, with the exception of glucose, polysorbate 80 and the synthetic vitamins, could be preserved at least for one month under toluene in the cold without previous heat sterilization. This medium will be useful for the routine microbiological assay of the B-vitamins with various lactic acid bacteria in natural materials.