Glucose-6-phosphate dehydrogenase and xylitol production by Candida guilliermondii FTI 20037 using statistical experimental design

Abstract

The aim of this work was evaluate the G6PD and xylitol production by Candida guilliermondii grown in rice straw hemicellulosic hydrolysate. Fermentative assays were carried out to evaluate the effect of pH ( X 1), xylose concentration ( X 2), and inoculum level (X 3) on the production of G6PD and xylitol. For optimization of G6PD production it was employed the methodology of experimental design. The estimated model predicts a maximum specific activity of 0.64 U mg −1 being possible a variation of 0.55–0.72 U mg −1 for response specific activity of G6PD (As), in the confidence level of 95%. For the model validation, it was attained 0.60 U mg −1 with 70 g L −1 xylose, pH 7.5 and 1 g L −1 of inoculum level. Indeed, C. guilliermondii proved to be a potencial source of intracellular enzyme (G6PD) when grown in a low cost fermentation medium as well as efficient in xylose–xylitol bioconversion.