title: Cloning of LicB from Clostridium thermocellum and its efficient secretive expression of thermostable β-1,3-1,4-glucanase.
abstract: β-1,3-1,4-glucanase is a widely used enzyme in brewing and in animal feed processing. To produce the bacterial enzyme at an industrial scale, the enzyme should be able to be secreted from microbial cells into fermentation broth and be stable in different conditions. In this study, the LicB gene encoding β-1,3-1,4-glucanase (lichenase) from Clostridium thermocellum was secretively expressed in a secretive strain, Bacillus subtilis WB800, with eight extracellular protease deletion which made LicB expressed obviously and reached 1.18 U/g cell mass. The secreted β-1,3-1,4-glucanase was found to be active from 40 °C to 80 °C and achieved the optimal activity at 80 °C. The enzyme also has a wide pH range (pH 4-11). The most common metal ions and chemicals were found to be inert on its activity. The property of LicB-encoded β-1,3-1,4-glucanase and its efficient secretive expression makes it a potential enzyme for industrial production and application.
authors.forename: Zichen
authors.initials: Z
authors.lastname: Luo
authors.forename: Qiuqiang
authors.initials: Q
authors.lastname: Gao
authors.forename: Xinliang
authors.initials: X
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Bao
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics; D003001:Cloning, Molecular; D048013:Acetivibrio thermocellus / Q000166:cytology / Q000201:enzymology* / Q000235:genetics*; D004795:Enzyme Stability; D005110:Extracellular Space / Q000201:enzymology; D015870:Gene Expression; D005818:Genetic Engineering; D005936:Glucans / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D013696:Temperature
chemical_list: D005936:Glucans; D006026:Glycoside Hydrolases; C028020:licheninase