Optimization of the media ingredients for cutinase production from Colleotrichum lindemuthianum using mixture design experiments.

Optimal concentrations of yeast extract, glucose and potassium phosphate in the fermentation medium have been identified for the maximum cutinase production from the fungi Colleotrichum lindemuthianum. A simplex lattice experimental design for mixtures was used to identify concentration ranges that yield maximum production. Three sets of experiments were performed all involving three ingredients. The sets of experiments differ in the number of concentration levels considered. In the first set we consider four concentration levels (i.e., 0%, 33%, 67%, 100%), and in the second and third sets we consider five and six levels, respectively. Results showed that the interactions among the nutrient ingredients are best captured when five- and six-level experiments are carried out. An algorithm has been proposed in this study to design the optimal medium. Various models were also developed to predict the enzyme production, and it is concluded that the cubic model obtained using six-level experimental data gives the best model. The study also highlighted the synergistic interaction between yeast extract and glucose toward cutinase production.