Abstract
Bacillus sp. KSM-635, which was isolated from soil, constitutively produced an alkaline carboxymethyl cellulase (CMCase) in quantity. Maximum cell growth was observed at an initial pH between 9 and 10, and no growth occurred below pH 8, thus illustrating the alkalophilic nature of this organism. Higher production of the CMCase required the presence of sugars (e.g., fructose, sucrose, maltose and mannitol) and complex nitrogen, with an initial pH of 8-9.
The CMCase, partially purified by precipitation with ethanol, showed an optimum pH for activity of 9.5 and an optimum temperature of 40°C, in glycine-NaOH buffer. It showed strong activity toward CMC, but very little activity toward p-nitrophenyl-β-D-glucoside or cellulosic substrates showing high crystallinity. Activity toward p-nitrophenyl-β-D-cellobioside was detected at pH 7, but it amounted to less than 2% of the maximum CMCase activity. Characteristically, the alkaline CMCase activity was not affected by various laundry components, such as surfactants, chelating agents and alkaline proteinases.
