Influence of environmental factors on lipase production by Lactobacillus plantarum

A strain of Lactobacillus plantarum, DSMZ 12028 (Deutsch Sammlung von Mikro organismen und Zellkulturen), isolated from a Portuguese dry fermented saus age, "chourico", was found to produce true lipase, producing free fatty aci ds from triolein (olive oil). This enzymatic activity was found in whole ce lls, but was negligible in comparison to lipolytic activity in culture supe rnatant. Therefore, only extracellular activity was studied. The effect of pH, temperature and glucose concentration on extracellular lipase productio n was studied in continuously stirred tank reactors, the first time this te chnology has been used to study the production of this enzyme in lactobacil li. Maximum lipase production was achieved at a pH of 5.5 and 30 degrees C and was kept at a significant level over a wide range of dilution rates (0. 05-0.4 h(-1)); the production of lipase was still significant for low pH va lues, temperature and glucose concentration, conditions that are close to t he ones present during chourico ripening. The effect of glucose concentrati on was also studied in a batch system. The control of lipase production was found to be related both to glucose concentration in the medium and to the growth rate/dilution rate. Glucose concentration was found to be important for fast lipase production, although it did not influence the maximum lipa se activity reached in a batch culture.