海洋细菌 sp. BY01 冷适应壳聚糖酶的克隆与特性分析。

Cloning and Characterization of a Cold-adapted Chitosanase from Marine Bacterium sp. BY01.

机构信息

School of Basic Medicine, Qingdao University, Qingdao 266071, China.

First Institute of Oceanography, Ministry of Natural Resource, Qingdao 266061, China.

出版信息

Molecules. 2019 Oct 30;24(21):3915. doi: 10.3390/molecules24213915.

Chitosanase plays an important role in the production of chitooligosaccharides (CHOS), which possess various biological activities. Herein, a glycoside hydrolase (GH) family 46 chitosanase-encoding gene, , was cloned from marine bacterium sp. BY01 and heterologously expressed in . The recombinant chitosanase, CsnB, was optimally active at 35 °C and pH 5.0. It was also revealed to be a cold-adapted enzyme, maintaining 39.5% and 40.4% of its maximum activity at 0 and 10 °C, respectively. Meanwhile, CsnB showed wide pH-stability within the range of pH 3.0 to 7.0. Then, an improved reaction condition was built to enhance its thermostability with a final glycerol volume concentration of 20%. Moreover, CsnB was determined to be an endo-type chitosanase, yielding chitosan disaccharides and trisaccharides as the main products. Overall, CsnB provides a new choice for enzymatic CHOS production.

壳聚糖酶在壳寡糖（CHOS）的生产中发挥着重要作用，壳寡糖具有多种生物活性。本文从海洋细菌 sp. BY01 中克隆了一个属于糖苷水解酶（GH）家族 46 的壳聚糖酶编码基因，并在中异源表达。重组壳聚糖酶 CsnB 的最适活性温度为 35°C，最适 pH 值为 5.0。它还是一种耐冷酶，在 0°C 和 10°C 时分别保持其最大活性的 39.5%和 40.4%。同时，CsnB 在 pH 3.0 至 7.0 的范围内具有较宽的 pH 稳定性。然后，建立了一种改进的反应条件，最终甘油体积浓度为 20%，以提高其热稳定性。此外，CsnB 被确定为一种内切型壳聚糖酶，主要产物为壳聚糖二糖和三糖。总的来说，CsnB 为酶法 CHOS 生产提供了新的选择。