Pectinase and polygalacturonase production by a thermophilic Aspergillus fumigatus isolated from decomposting orange peels

A thermophilic fungal strain producing both pectinase and polygalacturonase was isolated after primary screening of 120 different isolates. The fungus was identified as Aspergillus fumigatus Fres. MTCC 4163. Using solid-state cultivation, the optimum levels of variables for pectinase and polygalacturonase (PG) production were determined. Maximal levels of enzyme activities were achieved upon growing the culture in a medium containing wheat bran, sucrose, yeast extract and (NH4)(2)SO4 after 2-3 days of incubation at a temperature of 50 degrees C. Highest enzyme activities of 1116 Ug(-1) for pectinase and 1270 Ug(-1) for polygalacturonase were obtained at pH 4.0 and 5.0, respectively.