The Effects of Lysolecithin on the Growth of Lactobacillus casei in Relation to Biotin, Pantothenic Acid, and Fat-soluble Materials with Biotin Activity.

Williams and Fieger (1946) found that Lactobacillus casei could be grown continuously in a medium containing only traces of biotin if oleic acid was present at a suitable concentration. Trager (1947) observed a similar effect with a neutral oil (designated FSF) obtained from hydrolyzed horse plasma. This material, which had some biotin activity for chickens as well as for bacteria, permitted full growth of L. casei even in the presence of enough fresh egg white to inactivate completely any traces of biotin which might have been present in the medium. These results have been confirmed and extended (Williams and Fieger, 1947; Axelrod, Hofmann, and Daubert, 1947; Hofmann and Axelrod, 1947; Williams, Broquist, and Snell, 1947). Lecithin exerts growth-stimulating effects on the lactic acid bacteria (Bauernfeind, Sotier, and Bowff, 1942; Strong and Carpenter, 1942) and can replace oleic acid for organisms requiring this material (Williams, Broquist, and Snell, 1947). It can also replace biotin in the growth of L. casei (Trager, unpublished). Since the effects of lecithin may be supposed to be a result of its oleic acid content, it seemed of interest to investigate the effects of lysolecithin, which differs from lecithin in that it does not contain an unsaturated fatty acid.