The production of alkaline protease was investigated in submerged cult
ure of Bacillus mycoides. The optimal conditions for enzyme production
were pH 9.0, 3% (w/v) dextrin as carbon source, (NH4)(2)SO4 (0.1%, w/
v) and peptone (0.1%, w/v) as nitrogen sources and KH2PO4 at 1.0 g/l.
The enzyme was immobilized on various carriers by different methods of
immobilization including physical adsorption, ionic binding covalent
binding, and entrapment. The enzymes prepared by physical adsorption o
n chitosan, ionic binding on Amberlite IR-120, covalent binding on chi
tin, and entrapment in 2% crosslinked polyacrylamide had the highest a
ctivites. The optimal reaction temperature of the immobilized enzymes
was shifted from 50 to 55 degrees C. The thermal and storage stabiliti
es of the free enzyme were significantly improved by the immobilizatio
n process. (C) 1998 Elsevier Science Ltd. All rights reserved.