Small-scale studies towards a rational use of bioaugmentation in an Antarctic hydrocarbon-contaminated soil

LUCAS RUBERTO; SUSANA VAZQUEZ; ROMINA DIAS; EDGARDO HERNANDEZ; SILVIA CORIA; GUSTAVO LEVIN; ALFREDO LO BALBO; WALTER MAC CORMACK

ANTARCTIC SCIENCE

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2010 vol. 22 p. 463 - 469

0954-1020

Bioaugmentation is a controversial strategy. In this work, the effect of the inoculum size and theabsence of natural microflora on the efficiency of hydrocarbon removal were studied. Two levels of inoculum (106 and 109 CFU g-1) were applied to soil microcosms containing sterile (S6 and S9) and non-sterile (NS6 and NS9) oil contaminated Antarctic soil. Community controls (CC) and biostimulated autochthonous microflora (BAM) were also included. Total heterotrophic aerobic (THAB) and hydrocarbon degrading (HDB) bacteria as well as total petroleum hydrocarbons (TPH) were analysed. At day 0, THAB and HDB counts (CFU g-1) showed no differences among CC, BAM and NS6 but significantly higher values were observed in NS9 and S9. At day 60, three different levels of HDB were observed. The lowerlevel was represented by CC (106 CFU g-1 ), a second group (5 x 107 CFU g-1) was represented by BAM, NS6, NS9 and S6, and the third level was constituted by S9 (1 x 109CFU g-1). TPH values at day 60 decreased significantly in all systems excluding the controls. NS6, NS9, S6 and S9 were not different from those corresponding to BAM. Results suggest that the bioaugmentation of a chronically diesel fuel-contaminated Antarctic soil is unlikely to be profitable or beneficial.