OBSERVATIONS ON THE USE OF LACTOBACILLUS LEICHMANNII 4797 IN THE MICROBIOLOGICAL ASSAY OF VITAMIN Blz

Lactobacillus leichmannii (ATCC 4797) was reported by Skeggs et al. (1) to grow in an otherwise complete medium in response to increasing amounts of the “animal protein factor.” The reports of Ott ef al. (2) and Emerson (3) have demonstrated the probable identity of crystalline vitamin Blz with the “animal protein factor.” The use of another strain of L. leichmannii (313) in the microbiological assay for vitamin Blz has been reported by Hoffmann et al. (4), and subsequent investigations have shown that strain 4797 of L. leichmannii also responds to crystalline vitamin Blz. In the course of our investigations of crystalline vitamin Blz in the nutrition of L. leichmannii, the various modifications in the basal medium and testing conditions that are described in this paper have been developed.