Multi-omics analyses reveal mechanism of cellulose degrading bacteria from gut of Tenebrio molitor as probiotics

Tenebrio molitor (TM) is known for efficient utilization of lignocellulosic resources, a process in which gut microbiota plays a crucial role. A cellulose degrading bacterium isolated from mealworms fed on lignocellulose waste was identified as Bacillus licheniformis N-5 through the whole genomic sequencing, which revealed abundant cellulose degrading gene clusters. The culture conditions for the strain were optimized to enhance cellulase production. Dietary supplementation with this strain significantly promoted the growth of TM, the conversion of lignocellulosic waste, and the antioxidant capacity of the host. Furthermore, transcriptomic analysis indicated that the probiotic effects of B. licheniformis N-5 were regulated by the up regulation of protein digestion and absorption, and the down regulation of cholesterol metabolism in the gut. These findings provide a novel strategy for utilization gut microbial resources from TM and hold significant potential for advancing the biological conversion of cellulosic waste using mealworms.