title: Phenol degradation by halophilic bacteria isolated from hypersaline environments.
abstract: Phenol is a toxic aromatic compound used or produced in many industries and as a result a common component of industrial wastewaters. Phenol containing waste streams are frequently hypersaline and therefore require halophilic microorganisms for efficient biotreatment without dilution. In this study three halophilic bacteria isolated from different saline environments and identified as Halomonas organivorans, Arhodomonas aquaeolei and Modicisalibacter tunisiensis were shown to be able to grow on phenol in hypersaline media containing 100 g/L of total salts at a concentration of 3 mM (280 mg/L), well above the concentration found in most waste streams. Genes encoding the aromatic dioxygenase enzymes catechol 1,2 dioxygenase and protocatechuate 3,4-dioxygenase were present in all strains as determined by PCR amplification using primers specific for highly conserved regions of the genes. The gene for protocatechuate 3,4-dioxygenase was cloned from the isolated H. organivorans and the translated protein was evaluated by comparative protein sequence analysis with protocatechuate 3,4-dioxygenase proteins from other microorganisms. Although the analysis revealed a wide range of sequence divergence among the protocatechuate 3,4-dioxygenase family, all of the conserved domain amino acid structures identified for this enzyme family are identical or conservatively substituted in the H. organivorans enzyme.
authors.affiliation: Departamento de Ciência de Alimentos-FEA, Universidade Estadual de Campinas-UNICAMP, Rua Monteiro Lobato, 80 CEP, Campinas, SP 13083-862, Brazil.
authors.forename: Maricy Raquel Lindenbah
authors.initials: MR
authors.lastname: Bonfá
authors.forename: Matthew James
authors.initials: MJ
authors.lastname: Grossman
authors.forename: Francine
authors.initials: F
authors.lastname: Piubeli
authors.forename: Encarnación
authors.initials: E
authors.lastname: Mellado
authors.forename: Lucia Regina
authors.initials: LR
authors.lastname: Durrant
mesh_terms: D000595:Amino Acid Sequence; D001673:Biodegradation, Environmental / Q000187:drug effects; D049308:Dioxygenases / Q000737:chemistry / Q000378:metabolism; D004777:Environment; D005798:Genes, Bacterial; D044129:Halomonadaceae / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D019800:Phenol / Q000378:metabolism* / Q000494:pharmacology; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D054712:Salinity; D017422:Sequence Analysis, DNA
chemical_list: D012336:RNA, Ribosomal, 16S; D019800:Phenol; D049308:Dioxygenases