Scientists Confer Cellulose-Degrading Ability to Yarrowia lipolytica for Consolidated Bioprocessing

The yeast Yarrowia lipolytica is not capable of growing on cellulose. The team of Zhong-peng Guo from Université de Toulouse in France identified and overexpressed two endogenous β-glucosidases in Y. lipolytica, enabling the yeast to use cello-oligosaccharides as a carbon source for growth.

Initially, different essential enzyme components of a cellulase cocktail were individually expressed in Y. lipolytica in order to establish the viability of the strategy. The team chose four enzymes, namely Trichoderma reesei endoglucanase I (TrEG I) and II (TrEG II) and CBH II (TrCBH II), as well as the CBH I from Neurospora crassa (NcCBH I) since they were successfully expressed in Y. lipolytica and were relatively active components.

Finally, the team coexpressed the four enzymes along with the described Y. lipolytica β-glucosidases. This resulted in an engineered Y. lipolytica strain that was able to grow both on model cellulose substrates and on industrial cellulose pulp. This engineered yeast platform could be the foundation for building a fully cellulolytic Y. lipolytica for use in consolidated bioprocessing of cellulose.