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Production of a Thermostable Pullulanase in Bacillus subtilis by Optimization of the Expression Elements
Author(s) -
Pang Bo,
Zhou Li,
Cui Wenjing,
Liu Zhongmei,
Zhou Zhemin
Publication year - 2020
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.202000018
Subject(s) - pullulanase , bacillus subtilis , biochemistry , starch , recombinant dna , enzyme , chemistry , bioreactor , strain (injury) , bacillaceae , ribosomal binding site , glycogen debranching enzyme , food science , biology , bacteria , ribosome , gene , rna , genetics , organic chemistry , glycogen synthase , anatomy
Pullulanase is a debranching enzyme commonly used in the starch processing industry. Production of a thermostable pullulanase with high activity is desired due to the application of the enzyme to starch processing at high temperature. In this study, a thermostable pullulanase with high activity is overproduced in Bacillus subtilis . Via improvement of the plasmid backbones, promoters, and ribosome‐binding‐site (RBS) sequences, an optimal recombinant strain B. subtilis WB800/RBS7 is obtained with an extracellular pullulanase activity of 154.9 U mL −1 in a shake flask, which is 136.8 times higher than that of the wild type. When the strain is cultured in a 5‐L bioreactor, the pullulanase activity is significantly improved to 269.1 U mL −1 (2.74 mg mL −1 ). These results are expected to aid pullulanase production in industrial starch debranching applications.