title: Bifunctional recombinant cellulase-xylanase (rBhcell-xyl) from the polyextremophilic bacterium Bacillus halodurans TSLV1 and its utility in valorization of renewable agro-residues.
abstract: The thermostable bifunctional CMCase and xylanase encoding gene (rBhcell-xyl) from Bacillus halodurans TSLV1 has been expressed in Escherichia coli. The recombinant E. coli produced rBhcell-xyl (CMCase 2272 and 910 U L-1xylanase). The rBhcell-xyl is a ~62-kDa monomeric protein with temperature and pH optima of 60 °C and 6.0 with T1/2of 7.0 and 3.5 h at 80 °C for CMCase and xylanase, respectively. The apparent Kmvalues (CMC and Birchwood xylan) are 3.8 and 3.2 mg mL-1. The catalytic efficiency (kcat/Km) values of xylanase and CMCase are 657 and 171 mL mg-1min-1, respectively. End-product analysis confirmed that rBhcell-xyl is a unique endo-acting enzyme with exoglucanase activity. The rBhcell-xyl is a GH5 family enzyme possessing single catalytic module and carbohydrate binding module. The action of rBhcell-xyl on corn cobs and wheat bran liberated reducing sugars, which can be fermented to bioethanol and fine biochemicals.
authors: Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110 021, India.
authors: Gurdeep
authors: G
authors: Rattu
authors: Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110 021, India.
authors: Swati
authors: S
authors: Joshi
authors: Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110 021, India. tsnarayana@gmail.com.
authors: T
authors: T
authors: Satyanarayana
mesh_terms: D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D020134:Catalytic Domain; D044602:Cellulases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018556:Crops, Agricultural; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D007218:Industrial Microbiology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014995:Xylosidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D044602:Cellulases; D014995:Xylosidases
keywords: Agro-residues; Bacillus halodurans TSLV1; Enzymatic saccharification; Recombinant bifunctional cellulase–xylanase; Xylo-oligosaccharides and cello-oligosaccharides