Enhanced degradation of insoluble chitin: Engineering high-efficiency chitinase fusion enzymes for sustainable applications

• Published in: Bioresource technology 2024-11, Vol.412, p.131401, Article 131401
• Main Authors: Chen, Xiao, Pang, Li, Yang, Wentao, Tian, Hong, Yi, Youjin, Xia, Bo
• Format: Article
• Language: English
• Subjects: Chitin degradation; Chitin-binding domain; Enzyme engineering; Fibronectin III domain; N-acetyl-D-glucosamine
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2024.131401

[Display omitted] •Characterization of PoChi reveals its efficacy in chitin degradation.•PoChi exhibits significant metal ion stability and high enzymatic activity.•Fusion enzymes demonstrate enhanced insoluble chitin degradation.•PoChi-FnIII-ChBD shows the highest activity among reported chitinases. N-acetyl-D-glucosamine and its dimer are degradation products of chitin waste with great potential in therapeutic and agricultural applications. However, the hydrolysis of insoluble chitin by chitinases remains a major bottleneck. This study investigated the biochemical properties and catalytic mechanisms of PoChi chitinase obtained from Penicillium oxalicum with a focus on enhancing its efficiency during the degradation of insoluble chitin. Recombinant plasmids were engineered to incorporate chitin-binding (ChBD) and/or fibronectin III (FnIII) domains. Notably, PoChi-FnIII-ChBD exhibited the highest substrate affinity (Km = 2.7 mg/mL) and a specific activity of 15.4 U/mg, which surpasses those of previously reported chitinases. These findings highlight the potential of engineered chitinases in advancing industrial biotechnology applications and offer a promising approach to more sustainable chitin waste management.