Changes in soil bacterial communities during a hydrocarbon-bioremediation mesocosms assay in Antarctica

VÁZQUEZ S; NOGALES B; RUBERTO L; HERNÁNDEZ E; MESTRE C; LALUCAT J; MAC CORMACK W

Pinamar, Buenos Aires, Argentina

Congreso; XLI Reunión Anual de la SAIB; 2005

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

An in situ bioremediation assay was performed in mesocosms prepared in 1m2 plots with diesel-oil polluted soil from Jubany station, Antarctica. Significant hydrocarbon degradation was observed in all treated plots. Bacterial communities in control (CC) and in plots subjected to different treatments [biostimulation (AB) and biostimulation + consortia bioaugmentation (M10 and J13)] were characterised by T-RFLP analysis of PCR amplified 16S rDNA, at three different times, followed by cluster analysis of the electrophoretic patterns. Bacterial communities in all plots were similar at the beginning of the experiment, but there were rapid changes (within three weeks) in the structure of communities in the treated plots, which were highly similar (82%) irrespective of the treatment applied. Consortia M10 and J13 were not detected as established components of the community in bioaugmented plots. The relative abundance of the predominant bacterial population in CC decreased by more than 40% in treated plots, while at least other five bacterial populations increased in those. Therefore, the treatments caused an increase in the equitability (J’) of the communities, although no major variations in Shannon diversity (H’) was observed. Our results show that hydrocarbon bioremediation in treated mesocosms was successful and it resulted in changes in bacterial communities.