Green bioconversion of insoluble chitin: chitinase development pathways via multi-strategy synergy

As one of the most abundant natural polysaccharides on Earth, chitin is limited in its high-value utilization by its natural insolubility and high crystalline structure. Enzymatic degradation-especially via chitinases-serves as a highly promising approach for the green bioconversion of insoluble chitin. This review systematically analyzes the structural barriers that hinder the degradation of insoluble chitin and elucidates the enzymatic hydrolysis mechanisms underlying its conversion. Recent advances in enhancing chitinase catalytic efficiency through protein engineering approaches-including directed evolution, rational design, and domain fusion-are comprehensively discussed. In addition, the review highlights the multi-strategy synergistic frameworks that integrate AI-assisted enzyme design, immobilization technology, and expression regulation to achieve high-performance chitin bioconversion, which is intended to provide valuable references for the efficient bioconversion and resource recycling of insoluble chitin.