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.

Insect antagonistic bio-inoculants for natural control of leaf-mining insect pests of French beans

“…Similarly, previous research findings showed that different strains of entomopathogenic fungi and Trichoderma spp. frequently display great genetic and biochemical versatility with the types and amounts of extracellular enzymes secreted noted to depend on the fungal species and strain pathogenicity (Aslam et al, 2010;Mustafa and Kaur, 2010;Fernandes et al, 2012).…”

Phytopathogenic organisms and mycotoxigenic fungi: Why do we control one and neglect the other? A biological control perspective in Malaysia

“…Under suitable ecophysiological conditions, these spores germinate and grow into hyphae, thereby colonizing the insect's cuticle. These hyphae are capable of producing hydrolyzing enzymes, which bore a tunnel through which the hyphae could penetrate into the insects' body cavity, and there proliferate further, thus killing the host (Fernandes, Valério, Feltrin, & Van Der Sand, 2012). Entomopathogenic fungi can grow over a wide range of temperatures, and some strains have the appropriate ecophysiological growth parameters for use in climates such as Malaysia (Borisade & Magan, 2015).…”

Analysis of variation in virulence of Beauveria bassiana against insect pests of pigeonpea using qPCR

“…Several research works have been done on the isolation, identification and purification of extra‐cellular cuticle degrading enzymes from EPF . However, the method described in this paper is of particular value for analysis of variation in virulence of entomopathogens using insect cuticles as substrate.…”