Statistical design and optimization of nutritional value production by an oleaginous yeast Yarrowia lipolytica cultured in industrial – waste molasses

Abstract

Abundant by-products from sugar mills as industrial-waste molasses can be used as a carbon source in yeast culture media. Yarrowia lipolytica is an interesting yeast used as a candidate for cultivation in molasses medium. Here, we used response surface methodology to derive a statistical model for the individual and interactive effects of pH, temperature, and shaking speeds on the production of yeast cells. Cultivation conditions of yeast were optimized using Design Expert based on a 23 factorial central composite design (CCD) for maximum yeast cell production. Optimal conditions for maximum Y. lipolytica 5151 cell masses were as follows: pH, 6.45; temperature, 30°C; Shaking speed, 165 rpm. The Design Expert represented the maximal numerical solution with a predicted cell mass production level at 8.96 g/L. The experimental production of Y. lipolytica 5151 cell mass yielded 8.27 g/L that is 7.67% deviated from the model. Whereas, the model of TISTR 5621 was not adequate for prediction. Yeasts cultured under statistic prediction provide 55.94% and 51.25% of total protein. Amino acid content and vitamin B1 (1.06 mg and 1.47 mg per 100 g of dried Y. lipolytica 5151 and 5621, respectively) provided the relevant information for an alternative supplement in aquatic feed.