Method:

Isolation of 122 bacterial strains of mimosa nodules was grown in the Maconkey culture medium to discard enterobacteria; the bacterial strains that resulted negative to this test, were inoculated in the culture medium containing only phenanthrene source carbon. Three isolates had the capacity to grow in this medium. The three strains were identified by sequence of the 16s ribosomal gene, their capacity to grow in the presence of phenanthrene was assessed by microbial growth curves; the ability to degrade phenanthrene of the three strains was quantified by mass-coupled gas chromatography.

Results:

The sequences obtained from the 16s ribosomal gene are genetically related to the strains of Burkholderia phenoliruptrix, Burkholderia phymatum and Rhizobium paknamense. The microbial growth of the three strains, supplied with phenanthrene, had a similar behavior to the control, which contained succinate as a carbon source. The strain of Burkholderia sp. BB26 degraded 78.5%, Burkholderia sp. BB24 68.5% and Rhizobium sp. BY8 99%.

Discussion:

The results of phenanthrene degradation by Burkholderia sp. BB26, Burkholderia sp. BB24 and Rhizobium sp. BY8 strains suggest that the three strains have potential to be used in bioremediation processes of soils contaminated with phenanthrene.