ECONOMIC NATURAL BROTH MEDIA FOR SPORE PRODUCTION OF BEAUVERIA BASSIANA (BALSAMO)VUILLEMIN AND BEAUVERIA BRONGNIARTII (SACC.) PETCH.

Abstract

Commonly available low-cost natural substrates, including agricultural products and byproducts, were evaluated for blastospore production by the entomopathogenic fungi Beauveria bassiana (Balsamo)Vuillemin and Beauveria brongniartii(Sacc.) Petch, two common entomopathogenic fungi in sugarcane ecosystem. Of the resources namely Sesame Seed Cake Extract (SSCE), Groundnut Seed Cake Extract (GSCE), Cotton Seed Cake Extract(CSCE), Coconut Cake Extract(CCE), Rice Bran Extract(RBE), Wheat Bran Extract(WBE), Red gram Husk Extract(RHE) and Jaggery solution tested at three different concentrations viz., 5,10 and 15% infused with 1% peptone and compared with Sabouraud Dextrose Broth(SDB),significant differences in the production of B.bassiana spores among the media, with SSCE (2.81 x 108 /ml) proven better than all other media tested including the standard, SD broth (0.77 x 108 /ml) irrespective of concentration were observed. Economics being a consideration, SSCE(1.94 x 108/ml), GSCE (1.48 x108/ml), CSCE (1.46 x108/ml) , Jaggery (1.39x108/ml) followed by CCE, RBE at 5% concentration are the best alternative media for effective spore production of B.bassiana which can be utilized depending upon availability and season For B.brongniartii spore production, irrespective of concentrations tested many media i.e., CCE( 11.93 x 107 /ml) , RBE ( 11.02 x 107 /ml),WBE (11.67 x 107/ml), RHE (8.27 x 107/ml)and CSCE (5.8 x 107/ml) were on par with each other and better than the rest, the standard SD medium, Jaggery, GSCE and SSCE which were on par among themselves. No significant differences due to concentration was observed in blastospore production of B. brongniartii and B. bassiana except in the case of Jaggery based medium for latter species. SSCE at 10%, 15% and CSCE 5% yielded the maximum number of B.bassiana spores per rupee spent on raw material (7.51 x109, 4.09 x109 and 4.08 x109 respectively) with the SD broth resulting in 0.68x109spores while WBE (15%), RBE (15%) yielded maximum B.brongniartii spores (2.92 x 109, 2.29 x109) per rupee with the standard SD broth being costlier, producing 10 times lesser spores (1.59 x 108).The intrinsic differences observed in spore production between the two species and possible implications of media on the virulence are discussed.