Screening, identification and transcriptome analysis of feather-degrading bacteria

Zhang Pengzhen¹, Xue Linlin¹, Yang Xiaojin², Fan Shouwu², Li Wang¹
1 College of Animal Science and Technology, Henan University of Science and Technology  2 Luoyang Oukebio Biotechnology Co., Ltd.

Abstract: [Objective] To screen and identify bacteria that efficiently degrade feathers from the natural environment, and to screen differentially expressed genes (DEGs) in these strains using transcriptomics to elucidate their molecular mechanisms of feather degradation. [Methods] Soil from areas where feathers have been stored for a long period was collected using the plum blossom stake sampling method. Bacteria capable of efficiently degrading feathers were isolated and screened using feather fermentation medium, and their morphological description and molecular biological identification were performed. The screened strains were inoculated into feather fermentation medium (experimental group) and LB medium (control group), respectively. After 36 h of cultivation, bacterial cells from both treatment groups were collected for transcriptome sequencing. DEGs in the experimental and control groups were then screened, and GO functional annotation and KEGG enrichment analysis were used to annotate the DEGs, exploring the key functions and pathways of DEGs in the feather-degrading bacterial degradation process. 【Results】A highly efficient feather-degrading strain, XS6, was screened. After 24 h of culture, it degraded 97% of feather twigs in the feather fermentation medium (feather 10.0 g/L), with a keratinase activity of 201.2 U/mL. Nitrite was detected in the medium after 36 h of culture. Morphological and molecular biological identification confirmed strain XS6 as *Bacillus albus*. Transcriptome sequencing results showed that 655 DEGs were screened between the two treatment groups, including 148 upregulated genes and 507 downregulated genes. GO functional annotation results showed that the DEGs were annotated into 32 functional groups across 3 major categories, with a higher proportion of annotated genes related to metabolic processes, cellular processes, cells, cellular components, and catalytic activity. KEGG enrichment analysis showed that the DEGs were mainly enriched in energy and material metabolism pathways, signal transduction pathways, and biosynthetic pathways. [Conclusion] A highly efficient Bacillus leucosus strain XS6 was successfully obtained, which participated in the synergistic effect among strains, energy metabolism, and synthesis of biomacromolecules during the degradation of feathers.