title: Characterization of a new oxygen-insensitive azoreductase from Brevibacillus laterosporus TISTR1911: toward dye decolorization using a packed-bed metal affinity reactor.
abstract: This study reports the identification of a new bacterial azoreductase from Brevibacillus laterosporus TISTR1911, its heterologous production in Escherichia coli, the biochemical characterization and immobilization for use in dye biodegradation processes. The recombinant azoreductase (BrAzo) is a monomeric FMN oxygen-insensitive enzyme with a molecular mass of 23 kDa showing a broad specificity for the reduction of synthetic azo dyes. Double hexahistidine-tagged BrAzo was immobilized onto a nickel chelating column and methyl orange was used to assess its degradation potential using a packed-bed reactor. The dye degradation is described by an exponential model in a downstream batchwise continuous flow mode operated with recycling. The complete degradation of methyl orange (170 μM at 600 mL/h) was achieved in 3 h and continued over 9 cycles. Coupling the immobilized BrAzo with glucose dehydrogenase for NADH regeneration yielded a shorter 1.5 h-degradation period that was maintained throughout 16 cycles.
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Weeranuch
authors.initials: W
authors.lastname: Lang
authors.forename: Sarote
authors.initials: S
authors.lastname: Sirisansaneeyakul
authors.forename: Lukana
authors.initials: L
authors.lastname: Ngiwsara
authors.forename: Sónia
authors.initials: S
authors.lastname: Mendes
authors.forename: Lígia O
authors.initials: LO
authors.lastname: Martins
authors.forename: Masayuki
authors.initials: M
authors.lastname: Okuyama
authors.forename: Atsuo
authors.initials: A
authors.lastname: Kimura
mesh_terms: D000595:Amino Acid Sequence; D001391:Azo Compounds / Q000302:isolation & purification; D001673:Biodegradation, Environmental / Q000187:drug effects; D019149:Bioreactors / Q000382:microbiology*; D058675:Brevibacillus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D003116:Color; D004396:Coloring Agents / Q000302:isolation & purification*; D005798:Genes, Bacterial / Q000235:genetics; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008670:Metals / Q000737:chemistry*; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D009601:Nitroreductases; D010100:Oxygen / Q000494:pharmacology*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011994:Recombinant Proteins / Q000302:isolation & purification; D016415:Sequence Alignment; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D008670:Metals; D012336:RNA, Ribosomal, 16S; D011994:Recombinant Proteins; C100258:methyl orange; D009247:NADH, NADPH Oxidoreductases; D009601:Nitroreductases; C021106:azoreductase; D010100:Oxygen
keywords: Azoreductase; Brevibacillus laterosporus; Immobilization; Methyl orange; Recycle packed-bed reactor