INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2023
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IF 8.2
Jianrong Chen,Dengfeng Yang,Yunkai Zhang,Liyan Yang,Qingyan Wang,Mingguo Jiang,Lixia Pan
In order to better utilize chitinolytic enzymes to produce high-value N -acetyl-D-glucosamine (GlcNAc) from chitinous waste, there is an urgent need to explore bi-functional chitinases with exceptional properties of temperature, pH and metal tolerance. In this study, we cloned and characterized a novel bi-functional cold-adaptive chitinase called Ca Chi18A from a newly isolated strain, Chitinilyticum aquatile CSC-1, in Bama longevity village of Guangxi Province, China. The activity of Ca Chi18A at 50 °C was 4.07 U/mg. However, it exhibited significant catalytic activity even at 5 °C. Its truncated variant Ca Chi18A_ΔChBDs, containing only catalytic domain, demonstrated significant activity levels, exceeding 40 %, over a temperature range of 5–60 °C and a pH range of 3 to 10. It was noteworthy that it displayed tolerance towards most metal ions at a final concentration of 0.1 mM, including Fe 3+ and Cu 2+ ions, retaining 122.52 ± 0.17 % and 116.42 ± 1.52 % activity, respectively. Additionally, it exhibited favorable tolerance towards organic solvents with the exception of formic acid. Interestedly, Ca Chi18A and Ca Chi18A_ΔChBDs had a low K m value towards colloidal chitin (CC), 0.94 mg mL −1 and 2.13 mg mL −1 , respectively. Both enzymes exhibited chitobiosidase and N -acetyl-D-glucosaminidase activities, producing GlcNAc as the primary product when hydrolyzing CC. The high activities across a broader temperature and pH range, strong environmental adaptability, and hydrolytic properties of Ca Chi18A_ΔChBDs suggested that it could be a promising candidate for GlcNAc production.
研究领域:
生物化学
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酶工程
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Liyan Yang,Mingbo Qu,Zhou Wang,Shiyong Huang,Qingyan Wang,Maochun Wei,Fei Li,Dengfeng Yang,Lixia Pan
GH19 (glycoside hydrolase 19) chitinases play crucial roles in the enzymatic conversion of chitin and biocontrol of phytopathogenic fungi. Herein, a novel multifunctional chitinase of GH19 (CaChi19A), which contains three chitin-binding domains (ChBDs), was successfully cloned from Chitinilyticum aquatile CSC-1 and heterologously expressed in Escherichia coli. We also generated truncated mutants of CaChi19A_ΔI, CaChi19A_ΔIΔII, and CaChi19A_CatD consisting of two ChBDs and a catalytic domain, one ChBD and a catalytic domain, and only a catalytic domain, respectively. CaChi19A, CaChi19A_ΔI, CaChi19A_ΔIΔII, and CaChi19A_CatD exhibited cold adaptation, as their relative enzyme activities at 5 °C were 40.7, 51.6, 66.2, and 82.6%, respectively. Compared with CaChi19A and other variants, CaChi19A_ΔIΔII demonstrated a higher level of stability below 50 °C and retained relatively high activity over a wide pH range of 5–12. Analysis of the hydrolysis products revealed that CaChi19A and CaChi19A_ΔIΔII exhibit exoacting, endoacting, and N-acetyl-β-d-glucosaminidase activities toward colloidal chitin. Furthermore, CaChi19A and CaChi19A_ΔIΔII exhibited inhibitory effects on the hyphal growth of Fusarium oxysporum, Fusarium redolens, Fusarium fujikuroi, Fusarium solani, and Coniothyrium diplodiella, thereby illustrating effective biocontrol activity. These results indicated that CaChi19A and CaChi19A_ΔIΔII show advantages in some applications where low temperatures were demanded in industries as well as the biocontrol of fungal diseases in agriculture.
研究领域:
微生物学
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酶学
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植物病理学
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生物技术
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PubMed
高影响因子
Microorganisms
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2024
·Vol. 12
·期 7
·1381
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IF 4.1
Xuezhi Shao,Hongliang Fang,Tao Li,Liyan Yang,Dengfeng Yang,Lixia Pan
Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that catalyze the oxidative cleavage of recalcitrant polysaccharides. There are limited reports on LPMOs capable of concurrently catalyzing the oxidative cleavage of both cellulose and chitin. In this study, we identified and cloned a novel LPMO from the newly isolated bacteriumChitinilyticum aquatileCSC-1, designated asCaLPMO10. When using 2, 6-dimethylphenol (2, 6-DMP) as the substrate,CaLPMO10 exhibited optimal activity at 50 °C and pH 8, demonstrating good temperature stability at 30 °C. Even after a 6 h incubation at pH 8 and 30 °C,CaLPMO10 retained approximately 83.03 ± 1.25% residual enzyme activity. Most metal ions were found to enhance the enzyme activity ofCaLPMO10, with ascorbic acid identified as the optimal reducing agent. Mass spectrometry analysis indicated thatCaLPMO10 displayed oxidative activity towards both chitin and cellulose, identifying it as a C1/C4-oxidized LPMO.CaLPMO10 shows promise as a key enzyme for the efficient utilization of biomass resources in future applications.
研究领域:
生物化学
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微生物学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）