title: Overexpression and characterization of thermostable chitinase from Bacillus atrophaeus SC081 in Escherichia coli.
abstract: The chitinase-producing strain SC081 was isolated from Korean traditional soy sauce and identified as Bacillus atrophaeus based on a phylogenetic analysis of the 16S rDNA sequence and a phenotypic analysis. A gene encoding chitinase from B. atrophaeus SC081 was cloned in Escherichia coli and was named SCChi-1 (GQ360078). The SCChi-1 nucleotide sequences were composed of 1788 base pairs and 596 amino acids, which were 92.6, 89.6, 89.3, and 78.9% identical to those of Bacillus subtilis (ABG57262), Bacillus pumilus (ABI15082), Bacillus amyloliquefaciens (ABO15008), and Bacillus licheniformis (ACF40833), respectively. A recombinant SCChi-1 containing a hexahistidine tag at the amino- terminus was constructed, overexpressed, and purified in E. coli to characterize SCChi-1. H(6)SCChi-1 revealed a hydrolytic band on zymograms containing 0.1% glycol chitin and showed the highest lytic activity on colloidal chitin and acidic chitosan. The optimal temperature and pH for chitinolytic activity were 50°C and pH 8.0, respectively.
authors.affiliation: Departments of Food and Nutrition, College of Medical and Life Science, Silla University, Busan, Korea.
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Cho
authors.forename: In Soon
authors.initials: IS
authors.lastname: Choi
authors.forename: Young Ju
authors.initials: YJ
authors.lastname: Choi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001407:Bacillus / Q000201:enzymology*; D001483:Base Sequence; D002686:Chitin / Q000378:metabolism; D002688:Chitinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D002686:Chitin; D002688:Chitinases