MEDINA Roxana Beatriz
ESTEROLYTIC AND LIPOLYTIC ACTIVITIES OF LACTIC ACID BACTERIA ISOLATED FROM EWE´S MILK AND CHEESE.
KATZ, M.; MEDINA, R.B:; GONZÁLEZ, S.N.; OLIVER, G.
JOURNAL OF FOOD PROTECTION
International Association for Food Protection
Año: 2002 vol. 65 p. 1997 - 2001
In the present work we report on the esterase and lipase activities of lactic acid bacteria Lactococcus, Leuconostoc, Lactobacillus and Enterococcus isolated from ewes milk and cheeses. Esterase activity was studied using a- and b-naphthyl derivative of 2 to 12 carbon atoms and post-electrophoretic detection. The lactic acid bacteria evaluated had intracellular esterase activities, which preferentially degraded the a- and b-naphthyl derivative of 2 to 6 carbon atoms. By studying post-electrophoretic was detected that some strains presented more of one esterase. Lipase activity was studied in intracellular and extracellular fractions using tributyrin, tricaprylin, triolein and milk fat as substrates. The intracellular and extracellular fractions of Leuconostoc mesenteroides O257, Lactobacillus plantarum O236 and Lactobacillus acidophilus O177 were able to hydrolyzed tributyrin. Lactobacillus plantarum O186, Lactobacillus acidophillus O252 and Enterococcus faecium O174, O409, O426 showed lipase activity associated with the intracellular fraction on tributyrin. Lactococcus lactis O233, Lactobacillus plantarum O155 and Lactobacillus casei O190 did not hydrolyze triglycerides. Not all strains that showed esterase activity exhibited high activity on triglycerides. Esterase and lipase activities were species- and strain-specific. Wide variations in activity between strains highlight the need for selecting appropriate starters to produce enzyme-modified cheese as well as in accelerated-ripened cheese.