title: Characterization of a thermo-alkali-stable laccase from Bacillus subtilis cjp3 and its application in dyes decolorization.
abstract: In this work, a novel bacterial strain exhibiting laccase activity was isolated from black liquor and identified as Bacillus subtilis cjp3. The CotA-laccase gene was cloned from strain cjp3 and expressed in Escherichia coli. The purified recombinant laccase has a maximum activity of 7320 U/L, maintaining high stabilities under a wide pH range and high temperature conditions. Nearly no loss of laccase activity was observed even at pH 9.0 after 10 h of incubation. Reactive blue 19, reactive black 5 and indigo carmine could be efficiently decolorized by the purified laccase in the presence of a mediator ABTS. More than 86% of tested dyes were removed in 4 h at pH = 9.0. The recombinant laccase can work well in a broad range of temperatures of 20-80°C(>80% relative activity). These special properties indicated the potential use of the CotA-laccase in treating wastewater containing synthetic dyes.
authors.affiliation: a Department of Environmental Engineering , Nanjing Forestry University , Nanjing , China.
authors.forename: Weichuan
authors.initials: W
authors.lastname: Qiao
authors.affiliation: a Department of Environmental Engineering , Nanjing Forestry University , Nanjing , China.
authors.forename: Jingping
authors.initials: J
authors.lastname: Chu
authors.affiliation: b Department of Chemical Engineering , Nanjing Forestry University , Nanjing , China.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Ding
authors.affiliation: c Key Laboratory of Soil Environment and Pollution Remediation , Institute of Soil Science, Chinese Academy of Science , Nanjing , China.
authors.forename: Xin
authors.initials: X
authors.lastname: Song
authors.affiliation: a Department of Environmental Engineering , Nanjing Forestry University , Nanjing , China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D004396:Coloring Agents / Q000032:analysis*; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D042845:Laccase / Q000737:chemistry* / Q000235:genetics; D010802:Phylogeny; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D000468:Alkalies; D004396:Coloring Agents; D011994:Recombinant Proteins; D014874:Water Pollutants, Chemical; D042845:Laccase
keywords: Bacillus subtilis; cotA-laccase; decolorization; prokaryotic expression