Abstract

Beauveria bassiana is an insect pathogenic fungus and is currently being exploited as an effective commercial mycoinsecticide. Solid state fermentation is the most efficient way to mass produce B. bassiana conidiospores on solid substrates. Statistical optimization strategy was adopted to maximize the conidia production through solid state fermentation. Four substrates viz., rice (polished), crushed sorghum, wheat bran and rice bran at variable moisture content and yeast extract concentration were used. A full factorial central composite design was used to design the experiment and response surface method was used to study the optimal parameters required for large scale production. Optimization of the two most important factors like moisture content and yeast extract concentration at varied levels conferred best conidial yield of 28.8 × 10⁹ /gm for the mixed substrate rice + wheat bran at 35% moisture content and 1.5% yeast extract concentration.

Key words: Beauveria bassiana, central composite design, conidiospores, response surface methodology, solid state fermentation.