title: Purification and characterization of a thermophilic 1,3-1,4-β-glucanase from Bacillus methylotrophicus S2 isolated from booklice.
abstract: An extracellular 1,3-1,4-β-glucanase-producing strain S2 was isolated from booklice and identified as Bacillus methylotrophicus. Furthermore, a homogeneous extracellular 1,3-1,4-β-glucanase GCS2 was purified by ammonium sulfate precipitation and cation-exchange chromatography. The gene for the 1,3-1,4-β-glucanase was cloned, and the nucleotide sequence was determined. Characterization of the purified enzyme revealed the molecular mass of 26 kDa and the optimum activity at pH 7.5, 55°C. The purified enzyme can highly hydrolyze carboxymethylcellulose including oat gum, barley β-glucan, CMC and lichenan, while low activity on avicel, cellobiose, filter paper, p-nitrophenyl β-d-cellobioside, and p-nitrophenyl β-d-glucoside, but no activity against microcrystalline cellulose or salicin. The enzyme was stable at wide range of pHs 5-10 and still maintained above 60% activity at 70°C. The enzyme activity was stimulated by Trixon X-100. The property of the enzyme GCS2 makes this enzyme a broad prospect in brewing and commercial detergent industry. To our knowledge, this is the first report of a 1,3-1,4-β-glucanase from microbes associated with booklice.
authors.affiliation: School of Life Science and Technology, Nanyang Normal University, Nanyang, 473000, PR China. Electronic address: qiuhongniu@hotmail.com.
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Niu
authors.affiliation: School of Life Science and Technology, Nanyang Normal University, Nanyang, 473000, PR China.
authors.forename: Guo
authors.initials: G
authors.lastname: Zhang
authors.affiliation: School of Life Science and Technology, Nanyang Normal University, Nanyang, 473000, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: School of Life Science and Technology, Nanyang Normal University, Nanyang, 473000, PR China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Ma
authors.affiliation: School of Life Science and Technology, Nanyang Normal University, Nanyang, 473000, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Shi
authors.affiliation: School of Life Science and Technology, Nanyang Normal University, Nanyang, 473000, PR China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Fu
mesh_terms: D000818:Animals; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D002266:Carboxymethylcellulose Sodium / Q000378:metabolism; D002475:Cellobiose / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D003001:Cloning, Molecular; D005936:Glucans / Q000378:metabolism; D005960:Glucosides / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008970:Molecular Weight; D008003:Phthiraptera / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity; D013696:Temperature; D001617:beta-Glucosidase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D005936:Glucans; D005960:Glucosides; D002475:Cellobiose; C025193:4-nitrophenyl beta-D-glucoside; C034170:4-nitrophenyl beta-cellobioside; D002482:Cellulose; D001617:beta-Glucosidase; D002266:Carboxymethylcellulose Sodium; C015968:lichenin
keywords: 1,3-1,4-β-Glucanase; Bacillus methylotrophicus S2; Booklice; Thermophilic; pH stable