title: Bacillus amyloliquefaciens laccase--from soil bacteria to recombinant enzyme for wastewater decolorization.
abstract: One hundred wild type strains of Bacillus sp. were isolated from industrial and agricultural soil across Serbia and screened for laccase activity. Three strains showed high laccase activity temperature optimum of 65 and 80 °C towards ABTS. A new laccase gene from the strain with highest temperature optimum, namely Bacillus amyloliquefaciens 12B was cloned and expressed in Escherichia coli. Recombinant laccase degraded dye Reactive blue 52 at pH 7.0 and pH 4.0 and at elevated temperature, while fungal laccases was unable to act on this substrate at pH higher than 4.0 and was quickly inactivated at temperatures higher than 45 °C. Degradation of dye was monitored by HPLC-DAD and resulting precipitate was analyzed by FTIR spectroscopy. Single product peak without chromophore was detected in solution, while water insoluble aggregate, presumably dye polymer is formed retaining blue color.
authors.affiliation: Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, Serbia. Electronic address: nloncar@chem.bg.ac.rs.
authors.forename: Nikola
authors.initials: N
authors.lastname: Lončar
authors.affiliation: Institute of Chemistry, Technology and Metallurgy-Center of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, Serbia.
authors.forename: Nataša
authors.initials: N
authors.lastname: Božić
authors.affiliation: Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Edifici Q, 08193 Bellaterra, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Lopez-Santin
authors.affiliation: Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, Serbia.
authors.forename: Zoran
authors.initials: Z
authors.lastname: Vujčić
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology*; D002851:Chromatography, High Pressure Liquid; D003116:Color; D042845:Laccase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012988:Soil Microbiology; D017550:Spectroscopy, Fourier Transform Infrared; D062065:Wastewater; D018508:Water Purification / Q000379:methods*
chemical_list: D042845:Laccase; D011994:Recombinant Proteins; D062065:Wastewater
keywords: Bacillus amyloliquefaciens; Biodegradation; Decolorization; Laccase