Streptomyces shaoguanensis sp. nov.: elucidating the mechanisms of efficient chicken feather degradation and its...

BACKGROUND: Feather waste, a byproduct of the poultry industry, remains underutilized due to its recalcitrant nature. While microbial conversion holds substantial potential, the scarcity of high-efficiency degrading strains hampers industrial application. RESULTS: A novel feather-degrading actinobacterium, designated KKT, exhibited highly efficient decomposition of feather waste. When cultured with 10% (w/v) chicken feathers as sole nutrient source, it achieved over 50% degradation within 8 days. Taxonomic characterization identified strain KKT as a novel species of the genus Streptomyces, with the proposed name Streptomyces shaoguanensis sp. nov.. Genomic analysis of strain KKT revealed an abundance of functionally uncharacterized genetic elements and 26 predicted biosynthetic gene clusters (BGCs) for secondary metabolites. Integrated transcriptomic and biochemical analyses suggested that feather degradation by S. shaoguanensis KKT represents an adaptive physiological response. This process was found to sustain an alkaline fermentation environment through continuous ammonia release and to efficiently disrupt disulfide bonds via a non-sulfite-dependent mechanism mediated by cysteine, H₂S and reductases. Simultaneously, highly efficient degradation was achieved through the temporally coordinated action of multiple proteases. Furthermore, when applied as a biofertilizer, the feather hydrolysate significantly promoted the growth of Brassica rapa subsp. chinensis (Pak Choi) compared to commercial amino acid fertilizers, achieving 13.1% higher fresh weight, 14.4% greater leaf area, 16.3% increased chlorophyll content, and 45.3% elevated soluble protein levels. CONCLUSIONS: Here, a novel Streptomyces species strain KKT with superior feather-degrading efficiency was reported. A wealth of functionally uncharacterized genes and significant biosynthetic potential in the genome of strain KKT laid a genetic groundwork for the exploration of its novel physiological functions and the discovery of uncharacterized metabolites. Integrative analyses of genomics, transcriptomics, and biochemical profiles of the degradation metabolites, together, uncovered the underlying mechanism of superior feather-degrading capacity. Additionally, the feather hydrolysate demonstrated a significant growth-promoting effect on Pak Choi. This finding provides a solid foundation for the sustainable valorization of feather waste and the development of novel biofertilizers.