Expression of cellulase in Candida glycerogenes and strengthen the expression level for application in residue-containing fermentation to enhance glycerol production.

Objectives: Expressing cellulase systems in C. glycerinogenes with extracellular secretion ability, and using fermentation with residue, enabled the recombinant strain to degrade lignocellulosic waste for efficient glycerol production, offering new option for agricultural waste transformation.

Results: Candida glycerinogenes is employed as the host strain, various cellulases were screened. Signal peptide mining and screening, and semi-rational design strategy was adopted in the host strain. The recombinant strain Cg4 had a total cellulase activity of 13.6 U/mL. Cg4 was applied to 110 g/L sugarcane bagasse hydrolysate with 40 g/L of pretreated bagasse as the substrate. The glycerol yield reached 50 g/L, with a 43.3% bagasse utilization rate, the amount of cellulase used in the degradation of lignocellulose was reduced by 12.1%.

Conclusion: Opened up a route for efficient degradation of agricultural waste of lignocellulose by C. glycerinogenes for glycerol production, the emission of lignocellulose waste had been reduced, and decreasing the need for cellulases in hydrolysis.