Novel Perspective on Valorization of Keratinous Materials using Microbial Consortia

Research output: Book/ReportPh.D. thesisResearch

Dingrong Kang

Rethinking about the sustainability of natural resources has become a hot topic in today’s world. Seeking renewable resources and utilization of new technologies are the potential means to cope with the challenges facing society such as scarcity of resources and environmental pollution. Many underlying resources including cellulose, chitin, and keratin are being exploited to satisfy the needs of industrial development. Keratinous materials are one of the most abundant proteins from vertebrates, representing an enormous feasible protein source, particularly from the commercial slaughterhouses or poultry farms. Nevertheless, keratin possesses unique biological characteristics such as insolubility and complicated molecular structures. The complete keratinolytic process is still not clarified clearly. Many attempts have been made to hydrolyze keratinous materials in terms of physicochemical treatment and enzymatic hydrolysis. Nevertheless, these approaches still have evident defects with regard to efficiency, environmental harm and practicality. A new strategy needs to be developed, raising the potential values and expanding the application prospect to keratinous materials. The major objective of this research project has therefore been to try and explore the novel perspective to valorize keratinous materials using microbial consortia. This thesis is composed of four themed chapters. In the introductory thesis chapter, the structural characteristics of keratin and the potential application values are introduced and subsequently the current main methods used to hydrolyze keratinous materials are presented. Thereafter, the focus shifts to the mechanism of keratinolysis on the basis of different processing methods. Following, I describe several considerable aspects to determine the optimal approach for the valorization of keratinous materials. In the end, microbial consortia and metagenomics are proposed for extensive applications in bioconversion, which also possess a great potential to probe into keratin degradation. This PhD-thesis has resulted in one published manuscript in a peerreviewed journal and the production of two draft manuscripts. All three manuscripts are the result of a sequential logical effort to explore ways of keratinous valorization. Manuscript I describes the enrichment process of microbial consortium KMCG6 from environmental samples. KMCG6 possesses efficient keratinolytic activity and high degrading reproducibility. The compositional change of microbes was observed based on 16s rRNA gene amplicon sequencing along with the sequential cultivation. Additionally, the nutrient content of keratin substrates was analyzed before and after microbial degradation. This explains that microbial consortia can be obtained and used to degrade keratinous materials effectively.
Original languageEnglish
PublisherDepartment of Biology, Faculty of Science, University of Copenhagen
Publication statusPublished - 2019

ID: 218615059