Natural hydrocarbon-biodegradation activity in aged soils from Neuquén, Argentina

RUBERTO, L; CUADRADO, V; MERINI, LJ; RODRIGUEZ TALOU, J; LO BALBO, A; GIULIETTI, AM; MAC CORMACK, W

San Miguel de Tucuman

Congreso; XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (S.A.I.B.).; 2009

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Petrochemistry activities usually produce contamination events. Soils in areas where petroleum is extracted are impacted by the presence of hydrocarbons and frequently also heavy metals. In situ action can not be taken without previous evaluation of the biological potential of the contaminated soil at laboratory scale. In this work, intrinsic hydrocarbon biodegradation activity in soils from Centenario oilfield (Neuquén) was evaluated in vitro using Erlenmeyers flasks containing 10 g of soil and 50 ml of saline medium. Soil was characterized in texture, hydrocarbon concentration and some heavy metal content. Flasks were incubated at 25°C and 250 rpm in a rotatory shaker for 8 d. Total heterotrophic aerobic bacteria (THAB) were evaluated by plate count and total petroleum hydrocarbons (TPH) by IR after alkaline extraction (pH 13) of samples at 0 and 8 d. Soil was sandy and although the analyzed metals (Pb, Hg, Cd, Zn, As and Cr) showed level of environmental concern TPH value was high (18840 ppm). Whereas abiotic control at d 8 was not statistically different compared with system at 0 d, system having biological activity reduced TPH to 7925 ppm (57.9% of removal) in eight days. THAB values increased from 7.2x105 UFC/g to 8.7x109 UFC/g (p<0.001). These results indicated that bioremediation of this soil would be possible using the degradative potential of the indigenous microflora