Isolation, optimization, and partial purification of amylase from Chrysosporium asperatum by submerged fermentation

A potent fungus for amylase production, Chrysosporium asperatum, was isolated from among 30 different cultures obtained from wood samples collected in the Junagadh forest, India. All of the isolated cultures were screened for their ability to produce amylase by submerged fermentation. Among the selected cultures, C. asperatum (Class Euascomycetes; Onygenales; Onygenaceae) gave maximum amylase production. In all of the different media tested, potato starch was found to be a good substrate for production of amylase enzyme at 30 degrees C and pH 5.0. Production of enzyme reached the maximum when a combination of starch and 2% xylose, and organic nitrogen (1% yeast extract) and ammonium sulfate were used as carbon and nitrogen sources, respectively. There was no significant effect of metal ions on enzyme activity. The enzyme was relatively stable at 50 degrees C for 20 min, and no inhibitory effect of Ca+2 ions on amylase production was observed.