Effect of Phenobarbitone on the Requirement of Lactobacillus leichmannii for Vitamin B₁₂

Abstract

WHEN sodium phenobarbitone (2 mgm. per ml.) is added to the medium used in a modified method for the microbiological assay of vitamin B₁₂ with Lactobacillus leichmannii as test organism, an increase occurs in the amount of growth produced by small amounts of vitamin B₁₂ ¹. This communication describes results which suggest that phenobarbitone has a specific vitamin B¹²-sparing action under the experimental conditions previously described¹. The strain of Lactobacillus leichmannii used was supplied by the National Collection of Industrial Bacteria, and is derived from the American Type Culture Collection strain No. 4797.