Resumo

The limitations of traditional techniques for the detection and identification of microorganisms are evident in the studies of diversity of microorganisms associated with a particular environment. In soils impacted by hydrocarbons, there are a large number of substrates and metabolites, which provide conditions for the development of a complex microbial community. Fifteen bacterial strains isolated from soil impacted by the oil spill have been studied in order to identify them and determine the capacity of degradation of recalcitrant compounds resulting from the metabolism of oil by these microorganisms. To identify those isolates the genomic DNA was extracted and used as a template for amplification by PCR of the 16S rDNA gene that encodes ribosomal RNA and comprises alternating regions of high and low variability used as an excellent molecular marker for the reconstruction of most phylogenetic relationships. The amplified product of 1200 bp (partial region of the 16S rDNA gene) was digested with different restriction endonucleases - Dde I, Hae III and BSTU I - and the profile of bands obtained were analyzed in 0.8 % agarose gel, showing from the fifteen isolates, 11 were distinct strains. For better identification, the V3 region of the 16S rDNA of those microorganisms were sequenced and aligned by the program MicroSeqID to identify them: strains 1 and 3 was identified as Achromobacter denitrificans, 96 % and 90 % of identity, 4 and 11 strains as Pseudomonas aeruginosa with 100 % of identity, strains 5 and 14 as Serratia nematodiphila with 98 % of identity, strain 6 as Janibacter limosus strain DSM 11140 with 97 % of identity, strain 7 as Enterobacter sp. strain 638 with 98 % of identity, strains 8 and 13 as Staphylococcus xylosus with 96 % of identity, strain 2 as Bacillus aerophilus with 94 % of identity, strain 9 as Citrobacter braekii with 99.2 % of identity, strain 10 as Micrococcus luteus with 97 % of identity, strain 12 as P. aeruginosa strain PAO1 with 98 % of identity and strain 15 as B. pumilus with 99.5% of identity. These microorganisms were identified in the literature as strains able to degrade recalcitrant compounds from oil spil. This capacity will be tested in the treatment of effluents resulting from oil refineries.