Oxidative stress levels in the entomopathogenic fungus Beauveria bassiana growing in very long-chain hydrocarbons

C. HUARTE-BONNET; N. PEDRINI

Mainz

Congreso; 47th Annual Meeting of the Society for Invertebrate Pathology. 2014 International Congress on Invertebrate Pathology and Microbial Control; 2014

Society for Invertebrate Pathology

Broad host range entomopathogenic fungi attack insect hosts via attachment to insect surface, with the subsequent production of degrading enzymes that help penetration through the cuticle.The outermost insect surface is covered by a lipid-rich layer, usually composed of very long-chain hydrocarbons. It is known that B. bassiana is able to grow on straight chain hydrocarbons (alkanes) as a sole source of carbon and energy, but it would have to pay a high cost to do so. The aim of this work was to study the oxidative stress levels in alkane-grown B. bassiana. For this purpose, we analyzed the gene expression pattern of sod1, sod2, and sod3 encoding superoxide dismutases, catA, catB, catC, catD, and catP encoding catalases, and gpx encoding glutathione peroxidase; and the enzymatic activity of SOD, CAT, and GPx in crude homogenates. Fungi grown either in hexadecane (n-C16) or octacosane (n-C28) showed overlapping but differential gene induction, with a concomitant increment in enzymatic specific activities, compared with controls grown in complete medium. These results confirm that high levels of reactive oxygen species are produced in B. bassiana during growth in alkanes, and an antioxidant response is triggered in fungal cells to overcome this drawback.