Characterization of thermo-tolerant and acid/alkali tolerant β-glucosidase from bacterial isolate M+

Abstract

242-247This study presents isolation and characterization of β-glucosidase (BG) from a bacterial isolate. Enzyme showed maximum activity at 50°C (2200 IU/l), however, relatively good activity (1600-1900 IU/l) was maintained even at higher temperature (60-80°C). Enzyme was thoroughly stable at 50-80°C for 30 min to 1 h and retained activity (75-100%), indicating its substantial thermo-tolerant nature. Maximum activity of BG was found at pH 6 (2200 IU/l), but significantly good activity was also observed at pH 5 (1800 IU/l), 7 (2000 IU/l), 8 (1900 IU/l) and 9 (1500 IU/l). Pb²⁺ caused considerable increase in enzyme activity (47%), while Zn²⁺ caused a little reduction (7%). SDS-PAGE showed a single band of BG (mol wt, 24 kDa)