Catalase production influences germination, stress tolerance and virulence ofLecanicillium muscariumconidia

Catalases are the most important enzymatic systems used to degrade hydrogen peroxide (H2O2) into water and oxygen, thereby lowering intracellular hydrogen peroxide levels. Entomopathogenic fungi display increased catalase activity during germination and growth, which is necessary to counteract the hyperoxidant state produced by oxidative metabolism. We studied the influence of five different hydrocarbons on catalase production by Lecanicillium muscarium to determine the importance of catalase induction in fungal germination, stress tolerance and virulence. Conidia produced by colonies grown on different hydrocarbons showed higher rates of catalase activity compared to the control and the catalase activity of conidia produced on n-octacosane was three times higher than the activity of the control. This increase in catalase activity was accompanied by a higher level of resistance to exogenous hydrogen peroxide and a reduction in the germination time. Our study has helped to identify that increased catalase activity improves the germination and tolerance to different antioxidant stress response of L. muscarium.