[beta]-Galactosidase of the Extreme Thermophilic Anaerobic Bacterium Thermoanaerobium sp. 2905 and Its Immobilization

The composition of a nutrition medium for cultivating the extreme thermophilic anaerobe Thermoanaerobium sp. 2905 was optimized, which enabled the bacterial β-galactosidase production to be substantially enhanced. Xylan and ammonium phosphate were selected as optimal carbon and nitrogen sources, respectively. The enzyme was purified fivefold by precipitation of the aqueous cell extract with alcohol (1 : 1, v/v), and a crude preparation with a specific activity of 46 U per mg protein was obtained. Cells of the extreme thermophile were entrapped in natural or synthetic latex.[PUBLICATION ABSTRACT]