Bioconversion of Poplar Wood Hemicellulose Prehydrolysate to Microbial Oil Using Cryptococcus curvatus

Abstract

Poplar wood hemicellulose prehydrolysate was used for microbial oil production using an oleaginous microorganism Cryptococcus curvatus. Initially, the effect of substrate concentration and nitrogen content was investigated on synthetic media. Then poplar wood prehydrolysate without detoxification was used as substrate in the fermentation. The result showed that this strain is capable of consuming both hexose and pentose sugars, a challenge in fermentation of hemicellulosic streams. It was able to accumulate 36.98% of lipid and the fermentation resulted in 13.78 g/L of biomass and 5.13 g/L of lipid under optimum conditions after 164 h of fermentation. The lipid product obtained was characterized in terms of their fatty acid profiles. Overall, this study shows that it is possible to produce microbial oil from a sustainable renewable feedstock like poplar wood hemicellulose prehydrolysate. This robust strain used has the ability to grow on industrially produced hemicellulose which can help in the development of an integrated biorefinery, where all the three components of lignocellulosic biomass are utilized.