Prof. Xiaochun Luo
South China University of Technology
Bioscience; Bioengineering; Fish immunology; Enzyme biotechnology
Microbes, Nitrogen Cycle and Biorefine
Nitrogen is one of the most important elements of all living things, and it is also the costliest component in animal, plant, and microbial nutrition. With the increase in the number of humans and the increased demand for animal protein, the livestock and aquaculture industries have produced a large amount of refractory nitrogenous biomass, including feathers (keratin) and chitin (amino sugar), which cannot be effectively used by humans. The microorganisms in the natural nitrogen cycle can efficiently degrade these refractory nitrogen-containing wastes and convert them into high-value nutrients, which has become the green and clean high-value utilization way of these wastes. Analyzing the enzymatic hydrolysis mechanism of related microorganisms and developing high-efficiency utilization processes have become a research hotspot in recent years. This study introduces the feather degradation mechanism of a high-efficiency Streptomyces strain, including its production and transportation of reducing agents, protease degradation and peptide amino acid transport, iron and aerobic respiration, metabolic regulation, etc., and the use of this strain to achieve feather’s solid-state fermentation, obtaining degraded feather meal with high soluble amino acid (about 30%) and polypeptide (about 20%) contents, which can be used as protein raw material to replace fish meal; Using recombinant microbial proteases and chitinases, the protein, chitin, astaxanthin and mineral in shrimp shell were zero-waste recovered; Using chitinase modified by chitin binding domain addition, one-step shrimp shell refining is realized.