Response of bacterial soil communities to a small oil-spill at the Argentine base Jubany on King George Island (Antarctica)

VAZQUEZ S.; MAC CORMACK W.; MONIEN P.; JÜRGENS J.; HELMKE E.

Congreso; 8th International Conference on Contaminants in Freezing Ground; 2012

In October 2009 an oil pipeline running from the fuel depot of Jubany base to the residential andlaboratory buildings broke and caused an oil contamination of the ice and snow-coveredsurrounding. Four months later soil samples were taken in close and greater vicinity to the spillsite as well as in the Potter Cove, however, due to snow and melt water runoff through theaffected area sampling was limited. One year later snow did not cover the area. Sampling wasrepeated approximately at the same places and some additional sites. At the spill site the soileven in greater depth was still impregnated by diesel oil whereas at the other sampling pointsneither smell nor visual appearance of oil residues were noticeable. Correspondingly, the TC%values of the soil samples were very low except for those from the spill site. Measurements ofthe hydrocarbon content, however, will show how much oil was left. In order to find out if andhow the spill affected the cold environment we studied 76 samples for changes in the bacterialcommunity on the basis of the 16S rRNA gene by means of DGGE. Most of the samplesshowed a high bacterial diversity in 2010 as well as in 2011 with only marginal changes in thetaxonomic structure during this period. In contrast, the diversity of the samples near the dieselspill site became clearly reduced. Some strong bands in the DGGE-gels indicated anenrichment of specific bacteria types. Clone libraries revealed that Actinobacteria together witha Betaproteobacterium prevailed in these communities and constituted obviously a naturalautochthonous potential for crude oil bioremediation.