Pretreatment of Luzhou distiller's grains for feed protein production using crude enzymes produced by a synthetic microbial consortium

Chinese distillers' grains (CDGs) have low fermentation efficiency due to the presence of lignocellulosic components, such as rice husk. In this study, a microbial consortium synthesized was used based on the functional complementarity principle to produce lignocellulolytic crude enzyme. The crude enzyme was used to hydrolyze CDGs. After enzymatic hydrolysis, lignocellulose was damaged to varying degrees and the crystallinity decreased. Subsequently, the feed protein was produced using yeast through two pathways. The results showed that the crude enzyme produced by the microbial consortium (comprising Trichoderma reesei, Aspergillus niger, and Penicillium) exhibited excellent enzymatic efficiency, yielding 27.88%, 19.64%, and 10.88% of reducing sugar, cellulose, and hemicellulose. The true protein content of CDGs increased by 53.49% and 48.35% through the first and second pathways, respectively. Notably, the second pathway demonstrated higher economic benefits to produce feed protein. This study provides a pathway for high-quality utilization of CDGs.

Automated summary

This study synthesized a microbial consortium to produce efficient crude enzyme for the hydrolysis of Chinese distillers' grains (CDGs). The hydrolysis damaged the lignocellulose and decreased its crystallinity. Through two pathways, the true protein content of CDGs significantly increased, with the second pathway demonstrating higher economic benefits.