Transcriptomics Reveals the Mechanism of Purpureocillium lilacinum GZAC18-2JMP in Degrading Keratin Material

Microbial degradation of keratin is characterized by its inherent safety, remarkable efficiency, and the production of copious degradation products. All these attributes contribute to the effective management of waste materials at high value-added and in a sustainable manner. Microbial degradation of keratin materials remains unclear, however, with variations observed in the degradation genes and pathways among different microorganisms. In this study, we sequenced the transcriptome of Purpureocillium lilacinum GZAC18-2JMP mycelia on control medium and the medium containing 1% feather powder, analyzed the differentially expressed genes, and revealed the degradation mechanism of chicken feathers by P. lilacinum GZAC18-2JMP. The results showed that the chicken feather degradation rate of P. lilacinum GZAC18-2JMP reached 64% after 216 h of incubation in the fermentation medium, reaching a peak value of 148.9 μg·mL^-1 at 192 h, and the keratinase enzyme activity reached a peak value of 211 U·mL^-1 at 168 h, which revealed that P. lilacinum GZAC18-2JMP had a better keratin degradation effect. A total of 1001 differentially expressed genes (DEGs) were identified from the transcriptome database, including 475 upregulated genes and 577 downregulated genes. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis of the DEGs revealed that the metabolic pathways related to keratin degradation were mainly sulfur metabolism, ABC transporters, and amino acid metabolism. Therefore, the results of this study provide an opportunity to gain further insight into keratin degradation and promote the biotransformation of feather wastes.