Sunday, July 24, 2011
Grand Ballroom, 5th fl (Sheraton New Orleans)
A cellulase-producing filamentous fungus was isolated from a wood sample collected in Thailand. The fungus, isolate KK21.1, produced neither asexual nor sexual spores when routinely cultured. However, ITS sequence comparison indicated its relationship with an unidentified leaf litter Ascomycetous fungus and a number of Coelomycetous fungi including Rhizopycnis and Phoma. When grown in Cellulase Production Medium at room temperature for 15 days, the fungus produced filter paperase (FPase), carboxymethyl cellulase (CMCase) and β-glucosidase activities at 0.58, 2.42 and 0.67 U.ml-1, respectively. Optimum temperatures of the isolate KK21.1 FPase, CMCase and β-glucosidase were at 50-60, 50-70, and 50°C, respectively. Both CMCase and β-glucosidase were thermosensitive whereas FPase was relatively stable at 70°C, with approximately 65 % of activity remaining after 3 hours. FPase and CMCase showed good activity at mildly acidic pH (pH 6-7) whereas β-glucosidase appeared acidophilic, with a broad optimal pH from pH 3-7. This study raises the importance in biomass turnover by the probably large number though obscure non-sporulating fungi.