文献类型：期刊文献

英文题名：High level production of a Bacillus amlyoliquefaciens chitosanase in Pichia pastoris suitable for chitooligosaccharides preparation

作者：Luo, Sa[1];Qin, Zhen[1,2];Chen, Qiming[1,2];Fan, Liqiang[1,2];Jiang, Lihua[1];Zhao, Liming[1,2]

机构：[1]East China Univ Sci & Technol, R&D Ctr Separat & Extract Technol Fermentat Ind, Sch Biotechnol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]SCICBT, Shanghai 200237, Peoples R China

年份：2020

卷号：149

起止页码：1034

外文期刊名：INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

收录：;EI(收录号：20242616304250);WOS:【SCI-EXPANDED(收录号:WOS:000525795400103)】；

基金：This work was financially supported by the National Natural Science Foundation of China (31701537), Shanghai Sailing Program (17YF1403500), "Chen Guang" (17CG28) project of Shanghai Municipal Education Commission and Shanghai Education Development Foundation. Fundamental Research Funds for the Central Universities (222201814031, 22221818014), the 111 Project (B18022) and Research Program of State Key Laboratory of Bioreactor Engineering.

语种：英文

外文关键词：Chitosanase; Chitooligosaccharides; Glycoside hydmlase family 46

摘要：Chitooligosaccharides (COS) are hydrolytic products of chitosan that are essential in functional food, medicine, and other fields due to their biological activities. Commercial COS are often prepared by the hydrolysis of chitosan by chitosanase. In this study, a glycoside hydrolase family 46 cluster B chitosanase from Bacillus amyloliquefaciens (BaCsn46B) was efficiently expressed in Pichia pastoris. The recombinant enzyme was secreted into the culture medium that reached a total extracellular protein concentration of 4.5 g/L with an activity of 89072 U/mL in a high cell density fermenter (5 L). The molecular mass of deglycosylated BaCsn46B was 29.0 kDa. Purified BaCsn46B exhibited excellent enzymatic properties, which had high specific activity (2380.5 U/mg) under optimal reaction conditions (55 degrees C and pH 6.5). BaCsn46B hydrolyzed chitosan yielded a series of COS with different degrees of polymerization by endo-type cleavage. The end hydrolytic products of BaCsn46B were chi tobiose and chi totriose, while no monosaccharide yield was evident in the hydrolytic reaction. The excellent secreted expression level and hydrolytic performance make the enzyme a desirable biocatalyst for the industrial preparation of COS. (C) 2020 Elsevier B.V. All rights reserved.