Open AccessImproved Properties of Bacillus coagulans β‐Galactosidase through Immobilization
Author(s) -
Batra N.,
Singh J.,
Joshi A.,
Sobti R. C.
Publication year - 2005
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.200520103
Subject(s) - calcium alginate , chemistry , chromatography , bacillus coagulans , calcium , hydrolysis , cellulose , immobilized enzyme , lactose , enzyme , biochemistry , organic chemistry , fermentation
Thermostable β‐galactosidase from Bacillus coagulans RCS3 was purified by successive column chromatography using DEAE‐cellulose and Sephadex G‐50. Immobilization of the purified enzyme was studied with DEAE‐cellulose and calcium alginate. The efficiency of β‐galactosidase retention was 87 % with DEAE‐cellulose (17 mg protein/mL of matrix) and 80 % with calcium alginate (2.2 mg protein/g bead). Comparative studies of immobilization displayed a shift in the optimum temperature from 65 °C to 70 °C provoked by DEAE‐cellulose, although no effect was observed with calcium alginate. The heat inactivation curve revealed an improvement in the stability ( t 1/2 of 14.5 h for the immobilized enzyme as compared to 2 h for the free enzyme at 65 °C) in a calcium alginate system. This immobilized enzyme has a wide pH stability range (6.5–11). β‐Galactosidase immobilized by DEAE‐cellulose and calcium alginate allowed a 57 and 70 % lactose hydrolysis, respectively, to be achieved within 48 h after repeated use for twenty times.