title: Comparative studies of phenotypic and genetic characteristics between two desulfurizing isolates of Rhodococcus erythropolis and the well-characterized R. erythropolis strain IGTS8.
abstract: Two Rhodococcus erythropolis isolates, named A66 and A69, together with the well-characterized R. erythropolis strain IGTS8 were compared biochemically and genetically. Both isolates, like strain IGTS8, desulfurized DBT to 2-hydroxybiphenyl (2-HBP), following the 4S pathway of desulfurization. Strain IGTS8 showed the highest (81.5%) desulfurization activity in a medium containing DBT at 30 degrees C. Strain A66 showed approximately the same desulfurization activity either when incubated at 30 degrees C or at 37 degrees C, while strain A69 showed an increase of desulfurization efficiency (up to 79%) when incubated at 37 degrees C. Strains A66 and A69 were also able to grow using various organosulfur or organonitrogen-compounds as the sole sulfur or nitrogen sources. The biological responses of A66, A69 and IGTS8 strains to a series of mutagens and environmental agents were evaluated, trying to mimic actual circumstances involved in exposure/handling of microorganisms during petroleum biorefining. The results showed that strains A69 and IGTS8 were much more resistant to UVC treatment than A66. The three desulfurization genes (dszA, dszB and dszC) present in strains A66 and A69 were partially characterized. They seem to be located on a plasmid, not only in the strain IGTS8, but also in A66 and A69. PCR amplification was observed using specific primers for dsz genes in all the strains tested; however, no amplification product was observed using primers for carbazole (car) or quinoline (qor) metabolisms. All this information contributes to broaden our knowledge concerning both the desulfurization of DBT and the degradation of organonitrogen compounds within the R. erythropolis species.
authors.affiliation: Laboratório de Genética Microbiana, Departamento de Microbiologia Geral, Instituto de Microbiologia Prof. Paulo de Góes (IMPPG), Centro de Ciências da Saúde (CCS), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
authors.forename: Silvia C C
authors.initials: SC
authors.lastname: Santos
authors.forename: Daniela S
authors.initials: DS
authors.lastname: Alviano
authors.forename: Celuta S
authors.initials: CS
authors.lastname: Alviano
authors.forename: Fátima R V
authors.initials: FR
authors.lastname: Goulart
authors.forename: Marcelo
authors.initials: M
authors.lastname: de Pádula
authors.forename: Alvaro C
authors.initials: AC
authors.lastname: Leitão
authors.forename: Orlando B
authors.initials: OB
authors.lastname: Martins
authors.forename: Claudia M S
authors.initials: CM
authors.lastname: Ribeiro
authors.forename: Mônica Y M
authors.initials: MY
authors.lastname: Sassaki
authors.forename: Carla P S
authors.initials: CP
authors.lastname: Matta
authors.forename: Juliana
authors.initials: J
authors.lastname: Bevilaqua
authors.forename: Gina V
authors.initials: GV
authors.lastname: Sebastián
authors.forename: Lucy
authors.initials: L
authors.lastname: Seldin
mesh_terms: D015373:Bacterial Typing Techniques; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis / Q000302:isolation & purification; D020459:Genes, rRNA; D005838:Genotype; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism; D010578:Petroleum; D010641:Phenotype; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012240:Rhodococcus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism*; D013876:Thiophenes / Q000378:metabolism*
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D010578:Petroleum; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; D013876:Thiophenes; D013455:Sulfur; D009584:Nitrogen; C016366:dibenzothiophene