Objective: We isolated bacterial strains with chitin-degrading activity from the digesta of large yellow croakers (Pseudosciaena crocea) fed with chitin-enriched trash fish, and characterized potential chitinases thereof.
Methods: Chitin-degrading strains were screened with colloidal chitin agar from the digesta of P. crocea fed with trash fish. The chitinase gene (chi-X) was cloned and expressed in Escherichia coli, and the enzymatic properties of the chitinase (CHI-X) were characterized.
Results: A Citrobacter freundii strain with chitin-degrading activity was isolated. The chitinase gene encodes a protein containing 493 amino acid residues, with a proposed glycoside hydrolase family-18 catalytic domain. CHI-X could hydrolyze colloidal chitin. The optimal pH for CHI-X was 4.0 at optimal temperature (60 ℃). CHI-X was active over a broad pH range, with around 90% of the activity maintained after incubation at pH between 3.0 and 11 for 1 h. The enzymatic activity of CHI-X was stimulated by Mn2+, Li+, and K+, but inhibited by Ag+. The enzyme was stable after treatment by proteases and grouper intestinal juice. CHI-X hydrolyzes colloidal chitin into GlcNAc and (GlcNAc)2. Furthermore, an synergic effect was observed between CHIX and ChiB565 (a chitinase from Aeromonas veronii B565) on colloidal chitin.
Conclusion: CHI-X from intestinal bacterium may be potentially used as feed additive enzyme for warm water marine fish.
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Biopolymers
January 2025
School of Pharmacy and Bioengineering, Keele University, Keele, UK.
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Key Laboratory of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, China.
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Hubei Key Laboratory for Precision Synthesis of Small Molecule Pharmaceuticals, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, School of Material Science and Engineering, Hubei University, Wuhan 430062, China. Electronic address:
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State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 15 North Third Ring Road East, Chaoyang District, Beijing 100029, China. Electronic address:
Conductive hydrogels have emerged as excellent candidates for the design and construction of flexible wearable sensors and have attracted great attention in the field of wearable sensors. However, there are still serious challenges to integrating high stretchability, self-healing, self-adhesion, excellent sensing properties, and good biocompatibility into hydrogel wearable devices through easy and green strategies. In this paper, multifunctional conductive hydrogels (PCGB) with good biocompatibility, high tensile (1694 % strain), self-adhesive, and self-healing properties were fabricated by incorporating boric acid (BA) and glucose (Glu) simultaneously into polyacrylic acid (PAA) and chitosan (CS) polymer networks using a simple one-pot polymerization method.
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Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea; Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Center for Agricultural Microorganism and Enzyme, Seoul National University, Seoul 08826, Republic of Korea; Center for Food and Bioconvergence, Seoul National University, Seoul 08826, Republic of Korea. Electronic address:
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