Some factors affecting cellulase production and activity by a thermotolerant aspergillus terreus R -4 from filter mud

ABSTRACT

The growth and cellulase production by the thermotolerant Aspergillus terreus R-4 grown on filter mud [FM] waste, as the sole carbon source, were optimal when the culture medium was composed of [g/I] FM, 25; casein, 4; KH[2]PO[4], 2; MgSO[4]. 7H[2]O, 0.5; NaCl, 2. The effect of adding various substrates in presence of FM was examined. The supplementation of glucose [5 g/I] to the fermentation medium stimulated maximal cellulase activity, but higher concentrations of glucose repressed production of cellulases. The optimal conditions for CMCase, FPase and cellobiase were at pH 4.8 and 60°C. The cellulolytic enzymes produced by A-terreus R-4 were stable over a wide range of pH values. Enzyme activity was assayed after exposure to elevated temperatures for 15 min and its thermal stability was determined