title: Cloning, expression, purification and application of a novel chitinase from a thermophilic marine bacterium Paenibacillus barengoltzii.
abstract: A novel chitinase gene (PbChi70) from a marine bacterium Paenicibacillus barengoltzii was cloned and functionally expressed in Escherichia coli. The recombinant enzyme (PbChi70) was purified to homogeneity with a recovery yield of 51.9%. The molecular mass of purified enzyme was estimated to be 70.0 kDa by SDS-PAGE. PbChi70 displayed maximal activity at pH 5.5 and 55 °C, respectively. It exhibited strict substrate specificity for colloidal chitin, glycol chitin, powdery chitin, and N-acetyl chitooligosaccharides with degrees of polymerization above three. The enzyme exhibited an endo-type cleavage pattern and hydrolyzed colloidal chitin to yield mainly (GlcNAc)2. Furthermore, colloidal chitin was hydrolyzed by PbChi70 to produce 21.6 mg mL(-1) (GlcNAc)2 with the highest conversion yield of 89.5% (w/w). (GlcNAc)2 was further separated by an active charcoal column with a purity of 99% and a final yield of 61%. The unique enzymatic properties of the chitinase may make it a good candidate for (GlcNAc)2 production.
authors: College of Food Science and Nutritional Engineering, The Research and Innovation Center of Food Nutrition and Human Health (Beijing), China Agricultural University, Beijing 100083, China.
authors: Shaoqing
authors: S
authors: Yang
authors: College of Food Science and Nutritional Engineering, The Research and Innovation Center of Food Nutrition and Human Health (Beijing), China Agricultural University, Beijing 100083, China.
authors: Xing
authors: X
authors: Fu
authors: Bioresource Utilization Laboratory, College of Engineering, China Agricultural University, Beijing 100083, China.
authors: Qiaojuan
authors: Q
authors: Yan
authors: College of Food Science and Nutritional Engineering, The Research and Innovation Center of Food Nutrition and Human Health (Beijing), China Agricultural University, Beijing 100083, China.
authors: Yu
authors: Y
authors: Guo
authors: College of Water Resources & Civil Engineering, China Agricultural University, Beijing 100083, China.
authors: Zhuqing
authors: Z
authors: Liu
authors: College of Food Science and Nutritional Engineering, The Research and Innovation Center of Food Nutrition and Human Health (Beijing), China Agricultural University, Beijing 100083, China. Electronic address: zhqjiang@cau.edu.cn.
authors: Zhengqiang
authors: Z
authors: Jiang
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism; D002686:Chitin / Q000031:analogs & derivatives / Q000378:metabolism; D002688:Chitinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D048271:Chitosan; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000378:metabolism; D015870:Gene Expression; D008970:Molecular Weight; D009844:Oligosaccharides; D056507:Paenibacillus / Q000201:enzymology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D009844:Oligosaccharides; D011994:Recombinant Proteins; C493484:oligochitosan; D002686:Chitin; D048271:Chitosan; C031610:glycolchitin; D002688:Chitinases; D000117:Acetylglucosamine
keywords: Characterization; Chitin; Chitinase; Gene cloning; N-Acetyl chitobiose production; Paenicibacillus barengoltzii