Comparative Metabolism of the R and S Variants of Lactobacillus plantarum (Orla-Jensen)

Abstract

By the dissociation of rapidly growing cultures of the S type of L. plantarum on glucose agar containing 4% NaCl, an R variant was obtained which failed to produce titrable acid in glucose broth after 1-8 days incubation at 37[degree] C. After prolonged incubation (8-26 days), detectable quantities of acid were found. The S variant utilized glucose and produced lactic acid in glucose broth in 8 days; the R variant did not. "Resting" cell suspensions of the S variant fermented arabinose, glucose, lactose, and raffinose; while the R type did not. The R variant grew in carbo-hydrate-free broth and peptone solns.; the S type failed to grow in these media. The R variant grew in alcoholic extracts of peptone with or without glucose; the S variant grew in these solutions only in the presence of glucose. The R variant grew sparingly in neutral casein solns.; the S type did not.