RESPONSE OF THE ENTOMOPATHOGENIC FUNGI BEAUVERIA BASSIANA AND METARHIZIUM ANISOPLIAE TO MOLASSES MEDIA FORTIFIED WITH SUPPLEMENTS

Abstract

The comparative response of the entomopathogenic fungi (EPF) Beauveria bassiana (Balsamo-Criv.) Vuill. and Metarhizium anisopliae Metch. to calcium chloride, chitin, lactic acid and polyethylene glycol 6000 (PEG) used as supplements in molasses media was evaluated. The supplements were incorporated into broth or agar media at different concentrations and three parameters, viz. biomass, radial growth and spore output were assessed. At a concentration range of 0.5-3.0%, calcium chloride significantly enhanced biomass, indistinctly altered radial growth and significantly increased spore output of B. bassiana. The supplement indistinctly affected biomass and radial growth but significantly enhanced spore output of M. anisopliae. Chitin (0.1-0.6%) significantly reduced biomass, did not affect radial growth and significantly reduced spore output of B. bassiana. In the case of M. anisopliae, chitin significantly enhanced biomass and radial growth at the higher concentrations but did not affect spore output. Lactic acid (0.5-3.0%) significantly enhanced biomass, reduced radial growth at higher oncentrations and reduced spore output at medium concentrations in B. bassiana. The supplement positively influenced biomass of M. anisopliae at higher concentrations, significantly reduced radial growth at all concentrations and indistinctly reduced spore output. PEG (1-6%) significantly enhanced biomass, favored radial growth and significantly, yet uniformly, promoted spore output in B. bassiana. In M. anisopliae too, PEG enhanced biomass at 2% and higher concentrations, did not affect radial growth and significantly favored spore output at the highest concentration. In correlation analysis of parameter response and supplement concentration, biomass showed significant positive correlations only for lactic acid and PEG in B. bassiana but for all supplements in M. anisopliae. Radial growth showed significant negative correlations for chitin and lactic acid in B. bassiana but lactic acid alone in M. anisopliae. Spore output showed significant negative correlation for chitin in B. bassiana but significant positive correlation for PEG in M. anisopliae. Based on the positive relationship and degree of response over that in control, alcium chloride and PEG emerged as the best supplements that can be used with molasses media for increased output of both B. bassiana and M. anisopliae in mass cultures.