To develop new enzyme-based strategies for the degradation and utilization of chitin-rich biomass waste, and to provide new biotechnological interventions for agriculture, medicine, industry, and marine environmental protection, we found that the efficient degradation of chitin polymers into oligomers or monomers is a key factor limiting the further application of chitinase-based technologies. Therefore, by screening three chitinases and chitin deacetylases derived from different microbial sources and assembling the synthetically optimized genes into expression plasmids for production in Escherichia coli, we constructed a recombinant genetic system for chitinase expression.
Through evaluation of protein expression levels, enzymatic activity, and determination of optimal reaction conditions, we optimized both the expression environment and gene sequences to improve the yield and catalytic efficiency of the recombinant chitinases. Furthermore, by adding shrimp and crab shell waste into chitinase-containing supernatants or whole-cell cultures, we enabled the conversion of low-value biomass into valuable products such as amino acids, calcium lactate, and high-purity chitin, thereby enhancing biomass utilization.
To further improve the degradation performance, we explored the synergistic action of chitinases with chitin deacetylases and determined the optimal enzyme ratio. These free enzymes were subsequently immobilized on epoxy resins to improve catalytic stability and allow repeated usage, thus achieving more sustainable enzymatic recycling. This integrated strategy is necessary to broaden the industrial application of chitin-degrading enzyme systems and ultimately to provide novel enzymatic solutions for the efficient degradation of marine pollutants containing chitin. The detailed component composition is shown in the table below (Table 1).