Mixture design for optimization of fermentation medium for cutinase production from Colleotrichum lindemuthianum

BIOT 83

Vishal Shah, ShahV@dowling.edu, Department of Biology, Dowling College, Oakdale, NY 11769 and Fred J Rispoli, Department of Mathematics, Dowling College, Dowling College, oakdale, NY 11769.
Culture medium optimization is a critical step in the fermentation process development and often continues throughout the production life of the fermentation product. Two of the most widely used statistical experimental designs are Plackett-Burman design, and fractional factorial design. In the current study, we would describe the use of mixture design experiments towards optimization of medium for cutinase production from the fungi Colletotrichum lindemuthianum. In the first stage of optimization, we screened whether starch, glucose, ammonium sulfate, yeast extract, magnesium sulfate and potassium phosphate have any influence on cutinase production. In the experimental design, we imposed the constraints that exactly one factor must be omitted in each set of experiments and no factor can account for more than 1/3 of the mixture. Thirty different sets of experiments were designed. Results obtained showed that while starch is found to have negative influence on the production of the enzyme, yeast extract and potassium phosphate have a strong positive influence. Magnesium sulfate, ammonium sulfate and glucose have low positive influence on the enzyme production. In the second stage, we used mixture design experiments to find the optimal concentration of glucose, yeast extract and potassium phosphate for maximum enzyme production and develop a model that illustrates the interaction amongst the media ingredients.