Partial purification and characterization of thermostable alkaline β-mannanase from Bacillus sp JB-99 suitable for pulp bleaching

Bacillus sp. JB-99, when grown in a chemically defined medium containing lactose as a carbon source, yielded 3,860U/ml extracellular beta-mannanase, which was high compared to other examined carbon sources. Among the nitrogen sources, yeast extract enhanced the enzyme activity. The enzyme production was growth-associated. The enzyme was optimally active at 65 degrees C, pH 10, and had a half-life of 190 min at 65 C. N-Bromosuccinamide and AgNO3, CuSO4, and HgCl2 strongly inhibited the enzyme, whereas Ca2+ stimulated the enzyme activity. The alpha-galactosidase enzyme production was not found in any of the enzyme assays.