Kinetic studies on exploring lactose hydrolysis potential of β galactosidase extracted from Lactobacillus plantarum HF571129

摘要: A novel intracellular β-galactosidases produced by Lactobacillus plantarum HF571129, isolated from an Indian traditional fermented milk product curd was purified and characterized. The is a hetrodimer with molecular weight of 60 kDa (larger subunit) 42 kDa (smaller subunit), as estimated sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). enzyme 7.23 fold ultrasonication, ultrafiltration filtration chromatography overall recovery 30.41 %. optimum temperature for hydrolysis its preferred substrates, o-nitrophenyl- β-D-galactopyranoside (ONPG) lactose, are 50 °C (both), pH these reactions 6.5 7.5, respectively. showed higher affinity ONPG (Km, 6.644 mM) compared to lactose 23.28 mM). Galactose, the end found be inhibited (47 %). activity drastically altered metal ion chelators EDTA, representing that this metalloenzyme. activated larger extent Mg(2+) (73 % at 1 mM), while concentrations Na(+) (54 % 100 mM), K(+) (16 % 100 mM) urea 100 mM). thermal stability study indicated inactivation energy Ed = 171.37 kJ mol(-1). Thermodynamic parameters such ∆H, ∆S ∆G, were determined function temperature. About 88 % hydrolyzed room within 1 h. suggested obvious superiority in industrial conversion process.