Production and regulation of extracellular chitinase by Aschersonia aleyrodis (Cordycipitaceae: Hypocreales)

Chitinases are virulence determination factors of entomopathogenic fungi which perform critical functions during degradation of insect cuticle. production of extracellular chitinases by aschersonia aleyrodis (cordycipitaceae; hypocreales) isolate a005 was investigated using different combinations of basal medium components. the effects of different carbon sources on chitinase activity and biomass production by a. aleyrodis were tested in media supplemented with simple or complex carbon sources individually or in combination. maximum chitinase activities (221.59±1.20 mu/ml) as well as maximum biomass production (16.37±1.59 mg/ml) were found in the supernatants from 1.5% n-acetylglucosamine (glcnac) plus 0.8% chitin. the effects of the divalent metal ions (iron and magnesium) on lipase activity were also studied. the divalent metal salts,cacl2,mgcl2 and znso4,inhibit chitinase activity at 10 and 100mm concentration whereas inhibition of chitinase activity by kcl,feso4 and edta was observed at higher concentrations only. the optimum ph for chitinase production was 5.7,and the optimum temperature 25°c. copyright 2012 zoological society of pakistan.