Cloning,Expressing and Characterizing a Novel Cold-Adapted Laminarinase from Marine Bacterium Wenyingzhuangia aestuarii OF219

Laminarinases reveal potential application in the field of food and biotechnology.In this research,a novel GH16 family laminarinase,designated as Lam16A_Wa,was cloned from the genome of marine bacterium Wenyingzhuangia aestuarii OF219 and expressed in Escherichia coli.Lam16A_Wa demonstrates a relatively low optimal reaction temperature(35℃)and a cold-adapted feature.Its optimal pH value is 6.0 and is stable in a broad pH range from 3.0 to 11.0.A glycomics strategy was employed to investigate the hydrolytic pattern of Lam16A_Wa.The enzyme was confirmed as a random endo-acting glycoside hydrolase.Its minimum substrate was laminarin pentasaccharide,and the major final products are oligosaccharides,including disaccharide to pentasaccharide.The Lam16A_Wa provides a novel and well-defined tool for the molecular tailoring of laminarin.

Wenyingzhuangia属海洋细菌产β-紫菜多糖酶的克隆表达及性质研究

从海洋细菌Wenyingzhuangia aestuarii OF219中挖掘到一种新颖的β-紫菜多糖酶编码基因por16Z,对其进行生物信息学分析。利用分子生物学技术进行异源表达,研究其生化性质,采用高效液相色谱-质谱联用技术对降解产物进行解析。生化性质研究表明:β-紫菜多糖酶Por16Z_Wa的最适反应温度为45℃,最适反应pH 6.5,在pH 4.0~9.0范围具有较好的稳定性,且该酶具有适冷性。作用方式结果表明:Por16Z_Wa为内切酶,其降解终产物主要由紫菜二糖构成,含有少量的四糖及六糖,且它们均为被修饰或取代后的紫菜寡糖。Por16Z_Wa作为紫菜多糖的新型工具酶,能够高效、定向制备紫菜二糖,对紫菜多糖的应用研究具有推动作用。