Statistical optimization for improved production of cyclosporin a in solid-state fermentation.

This work evaluates the effect of different amino acids on production of CyA production in solid-state fermentation that was previously optimized for different fermentation parameters by one-factor-at-a-time for the maximum production of CyA by Tolypocladium inflatum MTCC 557. Based on the Plackett-Burman design, glycerol, ammonium sulfate, FeCl3, and inoculum size were selected for further optimization by response surface methodology (RSM). After identifying effective nutrients, RSM was used to develop mathematical model equations, study responses, and establish the optimum concentrations of the key nutrients for higher CyA production. It was observed that supplementation of medium containing (% w/w) glycerol, 1.53; ammonium sulfate, 0.95; FeCl3, 0.18; and inoculum size 6.4 ml/5g yielded a maximum of 7,106 mg/kg as compared with 6,480 mg CyA/kg substrate using one factor at a time. In the second step, the effect of amino acids on the production of CyA was studied. Addition of L-valine and L-leucine in combination after 20 h of fermentation resulted in maximum production of 8,166 mg/kg.