Strain improvement of a fungus producing chitinase by a chemical mutagen

Microbial chitinases are commercially exploited for their biocontrol properties and generation of usefulproducts from chitinous waste. Availability of highly active chitinolytic enzymes is a major problem. Thepresent study was carried out to improve chitinase production by Aspergillus terreus using a chemicalmutagen, ethidium bromide. The organism was cultivated on lactose- yeast extract medium. Theproduction medium consisting of chitin- yeast extract medium was seeded at 10% level. The wild strainswere exposed to ethidium bromide in the concentration range 1.5- 6.0 ?g/mL. Generally, all the mutatedstrains showed an improved chitinase yield compared to the control. Highest yield was observed withthe strain exposed to 6 ?g/mL of ethidium bromide. The yield was 25.03 % higher compared to the wildstrain. The mutated strain was slimy in nature. Protein content of the mutated strain decreased by 11%.Ethidium bromide at a concentration of 1.5 ?g/mL was considered optional, at which the strain was stablewith increase of 21.80 % in enzyme activity and 4.41% increase in protein content. Increased enzymeyield with decreased non-specific protein could be useful in producing cost effective enzyme.