Author(s)

Hima Bindu Kumdam, Shweta N. Murthy, Sathyanarayana N. Gummadi

Applied Industrial Microbiology Laboratory, Department of Biotechnology, Indian Institute of Technology-Madras, Chennai 600 036, India.

Debaryomyces nepalensis NCYC 3413, halotolerant yeast isolated from rotten apple, was capable of utilizing components of hemicellulose hydrolysate such as glucose, galactose, mannose, xylose and arabinose. The organism utilizes xylose as a sole carbon source and produces xylitol. The Plackett-Burman design was applied to determine the specific medium components affecting xylitol production and found that xylose, K₂HPO₄, and ZnSO₄ were critical in augmenting xylitol production. These significant parameters were further optimized using response surface methodology. The optimum concentrations of xylose, K₂HPO₄, and ZnSO₄ were found to be 100 g/l, 10.6 g/l and 8.9 mg/l respectively. Under these optimal conditions the xylitol production increased from 27 g/l to 36 g/l with a yield of 0.44 g/g (57% increase in total yield). In addition, formation of the by product (glycerol) was decreased under optimal conditions.

Debaryomyces nepalensis; Xylose; Xylitol; Medium Optimization; Plackett-Burman Design; Central Composite Design

H. Kumdam, S. Murthy and S. Gummadi, "A Statistical Approach to Optimize Xylitol Production by Debaryomyces nepalensis NCYC 3413 in Vitro," Food and Nutrition Sciences, Vol. 3 No. 8, 2012, pp. 1027-1036. doi: 10.4236/fns.2012.38136.