Optimization of Culture Conditions and Production of Bio-Fungicides from Species under Solid-State Fermentation Using Mathematical Modeling.

Agro-industrial wastes suitable for economical and high mass production of novel species under solid-state fermentation were identified by optimizing the culture conditions using a mathematical model and evaluating the viability of the formulated bio-product. Fourteen inexpensive, locally available, organic substrates and cereals were examined using a one-factor-at-a-time experiment. The fungus colonized nearly all substrates after 21 days of incubation, although the degree of colonization and conidiation varied among the substrates. A mixture of wheat bran and white rice (2:1 ) was found to support maximum growth of AU131 (3.2 × 10 spores/g dry substrate) and AU158 (3.5 × 10 spores/g dry substrate). Using a fractional factorial design, the most significant growth factors influencing biomass production were found to be temperature, moisture content, inoculum concentration, and incubation period ( 0.05). Analysis of variance of a Box-Behnken design showed that the regression model was highly significant ( 0.05) with -values of 10.38 ( = 0.0027, AU131) and 12.01 ( < 0.0017, AU158). Under optimal conditions, maximum conidia yield of log (8.6) ( AU131) and log(9.18) () were obtained. For wettable powder species formulations, it was possible to maintain conidial viability at room temperature (25 °C) for eight months at concentrations above 10 CFU/g.