Response of a new rumen-derived Bacillus licheniformis to different carbon sources

Abstract

IntroductionBacillus licheniformis (B. licheniformis) is a microorganism with a wide range of probiotic properties and applications. Isolation and identification of novel strains is a major aspect of microbial research. Besides, different carbon sources have varying effects on B. licheniformis in regulating the microenvironment, and these mechanisms need to be investigated further.MethodsIn this study, we isolated and identified a new strain of B. licheniformis from bovine rumen fluid and named it B. licheniformis NXU98. The strain was treated with two distinct carbon sources—microcrystalline cellulose (MC) and cellobiose (CB). A combination of transcriptome and proteome analyses was used to investigate different carbon source effects.ResultsThe results showed that B. licheniformis NXU98 ABC transporter proteins, antibiotic synthesis, flagellar assembly, cellulase-related pathways, and proteins were significantly upregulated in the MC treatment compared to the CB treatment, and lactate metabolism was inhibited. In addition, we used MC as a distinct carbon source to enhance the antibacterial ability of B. licheniformis NXU98, to improve its disease resistance, and to regulate the rumen microenvironment.DiscussionOur research provides a potential new probiotic for feed research and a theoretical basis for investigating the mechanisms by which bacteria respond to different carbon sources.