JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2026
·Vol. 74
·期 28
·22088-22097
·
IF 6.7
Li Maoyue,Gui Minjuan,Wei Yingying,Sun Huihui,Zhao Ling,Cao Rong
Chitooligosaccharides (COSs) are functional oligosaccharides
whose
bioactivities depend on their degree of polymerization (DP). Enzymatic
production of well-defined COSs remains challenging due to the broad
product profiles of most chitosanases. Here, we employed a bidirectional
loop-engineering strategy to decipher the function of a conserved
loop (XDXXP) in GH46 chitosanases. Deleting this loop from Csn-BJ
reduced hydrolytic activity by 5% but shifted the maximal product
DP from 2 to 4 (yielding 14.2% ± 1.0% of DP4). Conversely, inserting
the corresponding loop segment into Csn-BAC enhanced activity by 36%
and increased the maximal product DP from 3 to 4 (yielding 20.2% ±
2.5% of DP4). Structural modeling, molecular docking, and molecular
dynamics simulations revealed that the loop modulates the geometry,
electrostatics, and hydrophilicity of the substrate-binding cleft,
thereby influencing substrate recognition and product specificity.
This work provides a promising strategy for tailoring chitosanases
to produce high-value, customized COSs for food applications.
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高影响因子
PROTEIN EXPRESSION AND PURIFICATION
·
2022
·
IF 2.025
Chengyao Xia,Ding Li,Mengyi Qi,Yanxin Wang,Yue Zhang,Yiheng Yang,Zejia Hu,Xin Du,Yuqiang Zhao,Kuai Yu,Yan Huang,Zhoukun Li,Xianfeng Ye,Zhongli Cui
Chitosanases hydrolyze chitosan into chitooligosaccharides (COSs) with various biological activities, which are widely employed in many areas including plant disease management. In this study, the novel chitosanase Aq Csn1 belonging to the glycoside hydrolase family 46 (GH46) was cloned from Aquabacterium sp. A7-Y and heterologously expressed in Escherichia coli BL21 (DE3). Aq Csn1 displayed the highest hydrolytic activity towards chitosan with 95% degree of deacetylation at 40 °C and pH 5.0, with a specific activity of 13.18 U/mg. Product analysis showed that Aq Csn1 hydrolyzed chitosan into (GlcN) 2 and (GlcN) 3 as the main products, demonstrating an endo-type cleavage pattern. Evaluation of antagonistic activity showed that the hydrolysis products of Aq Csn1 suppress the mycelial growth of Magnaporthe oryzae and Phytophthora sojae in a concentration-dependent manner, and the inhibition rate of P. sojae reached 39.82% at a concentration of 8 g/L. Our study demonstrates that Aq Csn1 and hydrolysis products with a low degree of polymerization might have potential applications in the biological control of agricultural diseases.
研究领域:
生物技术
·
微生物学
·
植物病理学
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高影响因子
Microorganisms
·
2025
·Vol. 13
·期 9
·2033
·
IF 4.2
Yanmei Cai,Xinyu Li,Shuang Chen,Qichao Liu,Hongxiang Lu,Jiahui Xie,Wei Li,Guiying Chen
Microorganisms with chitin-degrading capabilities play a crucial role in the biological control of crop pests and diseases as well as in the treatment of organic waste. In this study, a chitin-degrading bacterium, designated L2-2, was isolated from the intestine ofOdorrana margaretaecollected in Mount Emei, Sichuan, China. Based on physiological and biochemical characteristics, 16S rRNA gene sequencing, and phylogenetic analysis of 31 conserved housekeeping genes in the whole genome, strain L2-2 was identified as a member of the genusRoseateles, namedRoseatelessp. L2-2. This strain is able to grow on agar medium with colloidal chitin as the sole carbon source and form clear hydrolysis zones. After optimizing fermentation conditions (including concentrations of nitrogen and carbon sources, culture time, and pH), the enzyme activity was increased to 3.46 U/mL, which was 24 times higher than the initial enzyme activity. Functional genome annotation showed that the strain contains genes encoding endochitinases of the GH18, GH23, and GH46 families, as well as genes encoding β-glucosidases of the GH1, GH2, GH3, and GH109 families, indicating its genetic basis for chitin-degrading potential. This study expands the diversity of known chitin-degrading bacteria and provides a promising microbial resource for the bioremediation of chitinous waste and sustainable pest control in agriculture.
研究领域:
微生物学
·
环境生物技术
·
分子生物学
·
应用微生物学
·
生物修复
·
农业微生物学
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