Bioremediation of Antarctic soils: strategies towards the success of bioaugmentation

RUBERTO L; VÁZQUEZ S, DIAS R, HERNÁNDEZ E, MAC CORMACK

Mar del Plata

Congreso; XLIII Reunión Anual de la SAIB; 2007

SAIB

Inoculation of soils with bacteria in order to increase biodegradation activity showed contradictory results. The lack of successful in the use of bioaugmentation strategies is a well known problem. On one hand this failure has been attributed to predation and competition with the microbiota present in the target soil. On the other hand, the size of the inoculum appears as an important factor to take into account when a bioaugmentation strategy is chosen. In this work, the success in the establishment of a bacterial inoculum (M10) between sterile and non-sterile hydrocarbon-contaminated Antarctic soils was studied. Six systems were performed by triplicate in 20 ml flasks: a community control (CC), an autochthonous microbiota control (AB), bioaugmentation of non-sterile soil with 106 CFU/gr (M10 6) or 109 CFU/gr (M10 9) and finally bioaugmentation of sterile soil with 106 CFU/gr (E6) or 109 CFU/gr (E9). All systems were biostimulated (with N and P).Other experiment was carried out in bioaugmented plots in order to analyze if the same bacterial consortium was able to established in the studied soil. For this purpose the presence of the T-RFs pattern characteristic for the consortia was analyzed. The results obtained from these experiments showed that the level of inoculum should be higher than the level of the autochthonous microbiota in order to facilitate the establishment of the added microorganisms. It was also observed that in the analyzed soil some indigenous populations were similar to the inoculated consortium. These populations responded quickly to nutrient addition. Finally, higher abundances of populations from the inoculated consortium could be detected only at the beginning of the experiment