Variability in the production of extracellular enzymes by entomopathogenic fungi grown on different substrates

ABSTRACT

Entomopathogenic fungi are important controllers of pest-insects populations in agricultural production systems and in natural environment. These fungi have enzymatic machinery which involve since the recognition and adherence of spores in their hosts culminating with infection and death of these insects. The main objective of this study was to analyzed extracellular enzyme production of the fungi strains Beauveria bassiana, Metarhizium anisopliae and Paecilomyces sp when cultured on substrates. These fungi were grown in minimal media containing specific substrates for the analysis of different enzymes such as amylases, cellulases, esterases, lipases, proteases (gelatin and caseinase), pectinases and cuticles of Musca domestica larvae and adults. All the assays were performed with and without the presence of dextrose in the culture media. The quantification of enzyme activity was performed by the ratio of halo / colony (H/C) and the results subjected to variance analysis level of 5% (ANOVA) followed by post-Tukey test. All strains were positive for lipase and also they showed a high significant enzyme production for gelatin at concentrations of 4 and 1%. B. bassiana and Paecilomyces sp. were positive for amylase, pectinase and caseinase, and only Paecilomyces sp. showed cellulase activity.