Autolysis and intracellular enzyme release from cheese related dairy lactobacilli

Abstract

The ability of Lactobacillus helveticas, Lb. delbrueckii; subsp. bulgaricus, Lb. delbrueckii subsp. lactis, Lb. casei, Lb. plantarum, Lb. fermentum and Lb. brevis to lyse under various conditions of temperature, sodium chloride concentration and pH was investigated. Intracellular enzymes released from the cells in vitro and in a cheese system were also considered. A temperature close to the optimun temperature for growth, a pH varying from 5.5 to 6.5 and a sodium chloride concentration varying from 0.5 to 1.0 M as well as a freezing and thawing treatment seem to be the optimal conditions for cell autolysis. Enzymes release in vitro and in the cheese were found to be related to the rate of autolysis of the cells. © Inra/Elsevier, Paris.