Xylitol production and furfural consumption by a wild type Geotrichum sp.

Abstract

Background: Xylitol is a five carbons polyol with promising medical applications. It can be obtained from chemical d-xylose reduction or by microbial fermentation of Sugarcane Bagasse Hemicellulosic Hydrolysate. For this last process, some microbial inhibitors, as furfural, constitute severe bottleneck. In this case, the use of strains able to produce xylitol simultaneously to furfural neutralization is an interesting alternative. A wild-type strain of Geotrichum sp. was detected with this ability, and its performance in xylitol production and furfural consumption was evaluated. Furthermore, were analyzed its degradation products.

Results: Geotrichum sp. produced xylitol from d-xylose fermentation with a yield of 0.44 g·g^-1. Furfural was fully consumed in fermentation assay and when provided in the medium until concentration of 6 g·L^-1. The furfural degradation product is not an identified molecule, presenting a molecular weight of 161 g·mol^-1, an uncommon feature for the microbial metabolism of this product.

Conclusion: This strain presents most remarkable potential in performing furfural consumption simultaneous to xylitol production. Subsequent efforts must be employed to establish bioprocess to simultaneous detoxification and xylitol production by Geotrichum sp.