Karakteristik dan Kinetika Enzimatik β-Galaktosidase Isolat Bakteri AV-1 pada Susu Pasteurisasi

Abstract

Lactose is not found in natural product except from mammary gland. Lactose must be hydrolized into glucose and galactose by β-galaktosidasesenzyme. So that, it is posible to be absorb by intestine. The purpose of this research was determined differences in characteristic and kinetics of β- galaktosidases-enzyme produced by AV-1 selected isolate lactid acid bacteria and Lactobacillus bulgaricus in hydrolyzing pasteurized milk. The optimum condition of AV-1 isolate β-galaktosidase enzyme was on incubation time 25 minute, temperature 43 °C, pH 6.5, with activity 0.182 U/ml, while the optimum condition of Lactobacillus bulgaricus β-galaktosidase enzyme was on incubation time 20 minute, temperature 43 °C, pH 6.5, with activity 0.357 U/ml. The kinetics parameters (Vmaks. and apparent KM) of isolate AV-1 β-galaktosidase enzyme were 0.198 U/ml and 1.314 mM, while the kinetics parameters (Vmaks. and apparent KM) of Lactobacillus bulgaricus’ β-galaktosidase enzyme (as control) were 0.385 U/ml and 1.075 mM. The activity of β-galaktosidase AV-1 isolate statistically was different from Lactobacillus bulgaricus’ (P < 0.05).