Enrichment and characterization of an environmental microbial consortium displaying efficient keratinolytic activity

Abstract Keratin refers to a group of insoluble and recalcitrant protein materials. Slaughterhouses produce large amount of keratinous byproducts, which are either disposed or poorly valorized through costly thermochemical processes for animal feed formulation. Learning from nature, keratinolytic microbial consortia stand as a cost-efficient and environmental friendly way to valorize this recalcitrant resource. Directed selection was applied to enrich soil-born microbial consortia, using sequential batch cultivations in keratin medium, while measuring enzymes activity and monitoring consortia compositions via 16S rRNA gene amplicon sequencing. A promising microbial consortium KMCG6, featuring mainly members of Bacteroidetes and Proteobacteria, was obtained. It possessed keratinolytic activity with