Effectiveness of the natural bacterial flora, biostimulation and bioaugmentation on the bioremediation of a hydrocarbon contaminated Antarctic soil

LUCAS RUBERTO, SUSANA C. VAZQUEZ, WALTER P. MAC CORMACK

INTERNATIONAL BIODETERIORATION & BIODEGRADATION

Elsevier Ltd.

Lugar: Essex, UK; Año: 2003 vol. 52 p. 115 - 125

0964-8305

Microcosms systems (250 g soil in 1 l #asks) were performed in Jubany Station (King George Island, South Shetland Islands) to analyse biodegradation ofgas-oil in Antarctic soils under natural conditions. Abiotic loss ofhydrocarbons, biodegradation activity ofindigenous micro#ora and biostimulation with N and P were studied. In addition, biaugmentation with a previously isolated psychrotolerant strain (B-2-2) was analysed. Hydrocarbon concentration, heterotrophic and hydrocarbon-degrading bacterial counts and predominant bacterial groups were evaluated during 51 days. A signi=cant loss ofhydrocarbons was observed in abiotic control. Indigenous micro#ora showed increased heterotrophic counts and hydrocarbon-degrading/heterotrophic ratio. This fact was associated with a signi=cant degrading activity (35% higher than the control). Bioaugmentation with B-2-2 strain improved the bioremediation e@ciency (75% ofthe hydrocarbon was removed). High levels ofN and P produced an initial inhibition ofbacterial growth. Finally, bacterial diversity was reduced in contaminated soil. Our results showed that autochthonous bacterial #ora from Antarctic soils is able to degrade an important fraction of the gas-oil and that bioaugmentation represents a valuable alternative tool to improve bioremediation.