文献类型：期刊文献

英文题名：A Hyperthermostable Type II Pullulanase from a Deep-Sea Microorganism Pyrococcus yayanosii CH1

作者：Pang, Bo[1];Zhou, Li[1];Cui, Wenjing[1];Liu, Zhongmei[1];Zhou, Shengmin[2];Xu, Jun[3,4,5];Zhou, Zhemin[1]

机构：[1]Jiangnan Univ, Minist Educ, Key Lab Ind Biotechnol, 1800 Lihu Ave, Wuxi 214122, Jiangsu, Peoples R China;[2]East China Univ Sci & Technol, Sch Biotechnol, Biomed Nanotechnol Ctr, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[3]Shanghai Jiao Tong Univ, State Key Lab Microbial Metab, Shanghai 200240, Peoples R China;[4]Shanghai Jiao Tong Univ, Sch Life Sci & Biotechnol, Shanghai 200240, Peoples R China;[5]Shanghai Jiao Tong Univ, State Key Lab Ocean Engn, Shanghai 200240, Peoples R China

年份：2019

卷号：67

期号：34

起止页码：9611

外文期刊名：JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

收录：;EI(收录号：20193607399582);WOS:【SCI-EXPANDED(收录号:WOS:000484060800018)】；

基金：'This work is financially supported by a project funded by the International S&T Innovation Cooperation Key Project (SQ2017YEGH001004), the National Natural Science Foundation of China (21878125), the Natural Sciences Foundation of Jiangsu (BK20181206), the Priority Academic Program Development of Jiangsu Higher Education Institutions, the 111 Project (no. 111-2-06), and the Jiangsu Province "Collaborative Innovation Center for Advanced Industrial Fermentation" Industry Development Program.

语种：英文

外文关键词：Pyrococcus yayanosii CH1; pullulanase; hyperthermophilic enzyme; starch debranching enzyme; starch liquefaction; domain truncation

摘要：Pullulanase is a commonly used debranching enzyme in the starch processing industry. Because the starch liquefaction process requires high temperature, a thermostable pullulanase is desired. Here, a novel hyperthermostable type II pullulanase gene (pul(PY)) was cloned from Pyrococcus yayanosii CH1, isolated from a deep-sea hydrothermal site. Pul(PY) was optimally active at pH 6.6 and 95 degrees C, retaining more than 50% activity after incubation at 95 degrees C for 10 h. The thermostability was significantly higher than those of most pullulanases reported previously. To further improve its activity and thermostability, the N-terminal and C-terminal domains of Pul(PY) were truncated. The optimum temperature of the combined truncation mutant Delta 28N + Delta 791C increased to 100 degrees C with a specific activity of 32.18 U/mg, which was six times higher than that of wild-type Pul(PY). Pul(PY) and the truncation mutant enzyme could realize the combined use of pullulanase with a-amylase during the starch liquefaction process to improve hydrolysis efficiency.