Production of cellulases by a thermophilic fungus, Thermoascus aurantiacus A-131

A thermophilic fungus, strain A-l31, isolated from a soil sample produced cellulases in the culture fluid. The fungus (strain A-131) was identified as Thermoascus aurantiacus Miehe from its taxonomical characteristics. The cellulases of T. aurantiacus A-131 were produced constitutively without cellulase inducers. Moreover, their production was induced markedly by amorphous polysaccharides containing β, 4 linkages such as alkali-treated bagasse and xylan rather than crystalline cellulose. The cultivation of T. aurantiacus A-l31 at 45°C with 4% alkali-treated bagasse led to the production of about 70U/ml of CMCase after 4 days. The thermostability of the cellulolytic enzymes'of T. aurantiacus A-l31 was excellent and virtually no decreases in their activities were seen after preincubation at 60°C for 24 hr.