Hydrocarbon removal and bacterial community structure in on-site biostimulated biopile systems designed for bioremediation of diesel-contaminated Antarctic soil

DIAS, ROMINA L.; RUBERTO, LUCAS; CALABRÓ, ARIEL; LO BALBO, ALFREDO; DEL PANNO, MARIA T; MAC CORMACK, WALTER P.

POLAR BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2014

0722-4060

Several studies have shown that biostimulation can promotehydrocarbon bioremediation processes in Antarctic soils. However, the effect ofthe different nutrient sources on hydrocarbon removal heavily depends on thenutrients used and the soil characteristics. In this work, using a sample ofchronically contaminated Antarctic soil that was exposed to a fresh hydrocarboncontamination, we analyzed how a complex organic nutrient source such as fishmeal (FM) and a commercial fertilizer (OSEII) can affect hydrocarbonbiodegradation and bacterial community composition. Both amended and unamended(control) biopiles were constructed and controlled at Carlini Station andsampled at days 0, 5, 16, 30 and 50 for microbiological, chemical and molecularanalyses. FM caused a fast increase in both total heterotrophic and hydrocarbondegrading bacterial counts. These high values were maintained until the end ofthe assay, when statistically significant total hydrocarbon removal (71 %)was detected when compared with a control system. The FM biopile evidenced thedominance of members of the phylum Proteobacteria and a clear shift inbacterial structure at the final stage of the assay, when an increase ofActinobacteria was observed. The biopile containing the commercial fertilizerevidenced a hydrocarbon removal activity that was not statistically significantwhen compared with the untreated system and exhibited a bacterial communitythat differed from those observed in the unamended and FM-amended biopiles. Insummary, biostimulation using FM in biopiles significantly enhanced the naturalhydrocarbon-degradation activity of the Carlini station soils in biopilesystems and caused significant changes in the bacterial community structure.The results will be considered for the future design of soil bioremediationprotocols for Carlini Station and could also be taken into account to deal withdiesel-contaminated soils from other cold-climate areas.