The Microbiological Assay of Riboflavin and Nicotinic Acid in Urine

Abstract
Lactobacillus helocticus (casei [epsilon]) [L. helveti-cus (casei E)] NCTC No. 6375 requires riboflavin for its growth and the amt. of growth as measured by the quantity of lactic acid which appears in the medium, is proportional to the amt. of ribof lavin present, provided that all other requirements are optimum. A technic was worked out by which the riboflavin content of urine could be assayed. Similarly L. arabinosus 17/5 NCTC No. 6376.,could be used for the assay of nieotinic acid in the urine.