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.

Isolation and classification of a soil actinomycete capable of sulphur-specific biotransformation of dibenzothiophene, benzothiophene and thianthrene

“…), R. erythropolis isolates A66 and A69 (Santos et al . ) and G. alkanivorans RIPI90A (Shavandi et al . ).…”

Biodesulfurization: a mini review about the immediate search for the future technology

“…This technique considers phenotypic, genotypic and molecular characteristics of microorganisms. Santos et al (2007) started this polyphasic approach with two isolates of R. erythropolis. The authors showed that both isolates involved in the ''4S'' pathway, reached desulfurization rate of 81.5 %, indicating that the isolates meet the necessary requirements for biorefining fuels.…”

Whole-Genome Shotgun Sequencing of Rhodococcus erythropolis Strain P27, a Highly Radiation-Resistant Actinomycete from Antarctica

“…Members of the Rhodococcus genus have been intensively studied owing to their ability to survive under extreme conditions (3, 4), and these bacteria seem to be interesting targets for screening radiation-resistant genes (5). Furthermore, although many investigations have demonstrated the resistance of Rhodococcus bacteria to UVC exposure, there is a lack of information on their resistance to gamma radiation.…”