Nutrition research with lactic acid bacteria: a retrospective view.

From the above discussion, it is apparent that one or another of the lactic acid bacteria requires each of the B vitamins required by animals and that assay methods developed during study of nutrition of bacteria and yeasts have played a large role in the initial or independent discovery, isolation, and characterization of vitamins, vitamin derivatives, and functionally similar substances. Clear examples include biotin, biocytin, lipoic acid, nicotinic acid, pantothenic acid, pantetheine, folic acid and tetrahydrofolic acid (and their derivatives), pyridoxal, pyridoxamine, and pyridoxamine phosphate. Improved assay methods that use these organisms also have provided much of the currently available information concerning distribution and stability of the vitamins in natural products, while quantitative inconsistencies between assays, when traced to their origin, have frequently revealed previously unknown metabolic precursors, products, or functions of the vitamins and have provided explanations of the mechanisms by which certain peptide growth factors act. Extension of such studies to organisms that cannot yet be grown in media of known composition should provide additional insights into currently obscure areas of nutrition.