Construction of recombinant Yarrowia lipolytica and its application in bio-transformation of lignocellulose

Lignocellulose is a polysaccharide and an abundant biomass resource that widely exists in grains, beans, rice, and their by-products. Over 10million tons of lignocellulose resources and processing products are produced every year in China. Three recombinant Y. lipolytica strains with cellulase (-glucosidase, endoglucanase and cellobiohydrolase) were constructed. The enzymatic activities of these enzymes were 14.181U/mL, 16.307U/mL, and 17.391U/mL, respectively. The whole cell cellulases were used for a stover bio-transformation. The celluloses in the stover were partly degraded by the cellulases, and the degradation products were transformed into single cell protein (SCP) by the Y. lipolytica cells. After 15d of fermentation with the whole cell cellulases, the protein content of the maize stover and the rice straw reached 16.23% and 14.75%, which increased by 168.26% and 161.52% compared with the control, respectively. This study provides a new stage for the efficient utilization of stover in the feed industry.