May Beauveria bassiana secreted proteins be virulence factors?
Fungal virulence has been mostly associated with cuticle-degrading enzymes which can be regulated depending on nutrient conditions. However, few studies relate fungal virulence to fungal insecticidal secreted proteins. We report how the ability of secreting these proteins may be linked to conidial virulence which can be affected by nutrient factors. In this study we evaluated: (1) the virulence of the conidia of 4 Beauveria bassiana isolates (EABb 01/110-su, EABb 01/103-su, EABb 01/12-su and EABb 01/88-su) grown on 4 different media; Malt Extract Agar (MEA), Rice (R), Sabouroad Glucose Agar (SGA) and Infected 4th instar Galleria mellonella Larvae (IL), and (2) the toxicity of Fungal Insecticidal Proteins (FIP) obtained from those conidia when inoculating in Adamek’s liquid medium. Conidial suspensions were obtained from the 4 media, assessed on G. mellonella larvae and used for production of FIP which were injected in healthy G. mellonella larvae. In all isolates, probit analysis and p
