Esterase and lipase activities of Lactobacillus sanfranciscensis strains used in sourdough fermentation

The esterase and lipase activities of fifteen strains of Lactobacillus sanf ranciscensis were studied. Strains differed in esterase activity which mark edly decreased from beta-naphthyl butyrate to caprylate. Only L. sanfrancis censis C57 had a relatively high activity on beta-naphthyl laurate. Zymogra ms showed that strain C57 possesses two esterase enzymes, one, like all the other strains, active on beta-naphthyl butyrate and another which is activ e on C4 fatty acid ester but also on beta-naphthyl laurate. In contrast to all the other strains, the cell yield and growth rate of L. sanfranciscensi s C57 were moderately enhanced by the addition of 1-monolauroyl-glycerol to the culture medium. All strains showed a very weak lipase activity.