Cold-active chitinases that maintain robust catalytic performance at low temperatures are gaining attention as eco-friendly biocatalysts for energy-saving bioprocesses.In this study,a novel multifunctional chitinase o...Cold-active chitinases that maintain robust catalytic performance at low temperatures are gaining attention as eco-friendly biocatalysts for energy-saving bioprocesses.In this study,a novel multifunctional chitinase of GH18(CmChi18B)was successfully cloned from a newly identified mangrove-associated bacterium Chitinibacter mangrovi FCG-7^(T)in Escherichia coli.The enzyme CmChi18B demonstrated adaptability to cold environments,retaining 55%of its maximal activity at 0℃.It displayed optimal activity at 55℃and pH 5.5.CmChi18B demonstrated high activity across a broad pH range of 4.0-12.0.Substrate hydrolysis analysis indicated that CmChi18B possesses bi-functional capabilities,including exochitinase and N-acetyl-β-D-glucosaminidase activ-ities.After 24 h of incubation with colloidal chitin at 30℃,the enzyme achieved a N-acetyl-D-glucosamine(GlcNAc)conversion rate of 91.15%with a purity exceeding 98%.Intriguingly,the hydrolysis time for GlcNAc production varied with temperatures,with 0℃significantly impairing N-acetyl-β-glucosaminidase activity.These attributes position CmChi18B as a promising,low-energy biocatalyst for the sustainable production of GlcNAc and the valorization of chitin waste streams.展开更多
基金funded by financial support from the Science and Technology Major Project of Guangxi(Guike AA24206048,Guike AA24206044)the National Natural Science Foundation of China(Grant No.32360227 and 32360244)+2 种基金Innovation and Development fund of Guangxi Academy of Sciences(No.2024YGFZ504-103)the Basic Science and Research Foundation of Guangxi Academy of Sciences(CQ-C-202302)Guangxi Science and Technology Program(Gui Ke Fa[2024]102-4).
文摘Cold-active chitinases that maintain robust catalytic performance at low temperatures are gaining attention as eco-friendly biocatalysts for energy-saving bioprocesses.In this study,a novel multifunctional chitinase of GH18(CmChi18B)was successfully cloned from a newly identified mangrove-associated bacterium Chitinibacter mangrovi FCG-7^(T)in Escherichia coli.The enzyme CmChi18B demonstrated adaptability to cold environments,retaining 55%of its maximal activity at 0℃.It displayed optimal activity at 55℃and pH 5.5.CmChi18B demonstrated high activity across a broad pH range of 4.0-12.0.Substrate hydrolysis analysis indicated that CmChi18B possesses bi-functional capabilities,including exochitinase and N-acetyl-β-D-glucosaminidase activ-ities.After 24 h of incubation with colloidal chitin at 30℃,the enzyme achieved a N-acetyl-D-glucosamine(GlcNAc)conversion rate of 91.15%with a purity exceeding 98%.Intriguingly,the hydrolysis time for GlcNAc production varied with temperatures,with 0℃significantly impairing N-acetyl-β-glucosaminidase activity.These attributes position CmChi18B as a promising,low-energy biocatalyst for the sustainable production of GlcNAc and the valorization of chitin waste streams.
