Evaluation of sorbitol production by Debaryomyces hansenii

Sorbitol is a 6- carbon polyol, which is used in food industries as a precursor for production of many products due to its sweetness and high solubility. The application of microbial process for sorbitol production has recently been becoming of point of interest because of requirement for suitable fermentative conditions, being cost effective and less environmental pollutions. The purpose of this study was to produce sorbitol from sucrose by Debaryomyces hansenii isolated from the nature.
The sorbitol producing yeast strain was isolated in a medium containing 40% glucose and 1% yeast extract. Following identification of yeast using ITS gene sequencing, we focused on the process of fermentation and production of sorbitol from sucrose. The quality and quantity of sorbitol production was analyzed by thin layer chromatography, colorimetric method and Megazime kit.
The sorbitol producing yeast strain was isolated from pollen of Malva sylvestris flower, and was identified as D. hansenii. This strain produced 5.23 g l-1 sorbitol after 5 days in medium containing of 150 g l-1 sucrose.
In this study sorbitol was produced by a D. hansenii isolated from the nature. Due to high efficiency of sorbitol production from sucrose by yeast, isolation of sorbitol producing native yeasts and optimization of the production conditions can be helpful for increases in quality and quantity of sorbitol production.