ENTOMOPATHOGENOUS FUNGI DEGRADE EPICUTICULAR HYDROCARBONS OF TRIATOMA-INFESTANS

Studies were undertaken to analyze the ability of entomopathogenous fu ngi to degrade insect hydrocarbons. Strains of Beauveria bassiana and Metarhizium anisopliae pathogenic to the blood-sucking bug Triatoma in festans were grown on hydrocarbon and non-hydrocarbon insect lipid ext racts and on synthetic hydrocarbon-enriched media as the sole carbon s ource. Entomopathogenous fungi were shown to utilize hydrocarbons as t he only carbon source for their growth. Insect-derived hydrocarbons se rved more efficiently as metabolic fuel rather than synthetic compound s of similar structure. [H-3]n-Pentacosane, [11,12-H-3]3,11-dimethylno nacosane, and [C-14]n-hexadecane were catabolized into different amoun ts of polar lipids, free fatty acids, and acylglycerols. In experiment s using the branched alkane, labeled hydrocarbons of different chain l ength than the precursor were also synthesized. Evidence of complete c atabolism was obtained by a significant release of (CO2)-C-14 from [1- C-14]n-hexadecane. (CO2)-C-14 production might be used as a simple met hod to compare hydrocarbon utilization by fungal strains. These data d emonstrate that entomopathogenous fungi are able to transform a variet y of hydrocarbon structures into different lipid products, part of whi ch may be subsequently utilized for energy production and for the bios ynthesis of cellular components. These data are the first evidence of hydrocarbon catabolism and synthesis in entomopathogenous fungi. (C) 1 997 Academic Press.