Abstract

Soil contamination with heavy metals, such as copper (Cu) zinc (Zn), cadmiun (Cd), lead (Pb), mercury (Hg) nickel (Ni), chromium (Cr) and arsenic (As), is a widespread problem that affect several environment including pristine areas. Although Antarctica is often considered a remote and pristine environment, some ice-free areas have been subject to human impacts for 50 years or more. A high density of scientific stations is found in Arley Cove area, located on Maxwell Bay shoreline, Fildes Peninsula, King Geroge Island, also one of the most impacted areas in Antarctica. Recent results have been shown the trace metal contamination in surrounding areas near to the Chilean (Escudero) and Russian (Belinghousen), mainly related to high levels of Zn, Pb, Cd, Cr and Ni produced by anthropogenic sources. Little is known about the bacterial community in Fildes Peninsula in such soil and less about the taxa common to polluted soil. We wanted to know the effect of different physicochemical factors over bacterial community present on impacted and non impacted area. The use of tag-16S rDNA (Miseq-Illumina) was performed to quantify bacterial taxa and determine variations on the bacterial community structure present in heavy metals contaminated soils from Fildes Peninsula. Most of the sequences were assigned to the Proteobacteria (Betaproteobacteria and Gammaproteobacteria) and Actinobacteria. No differences between bacterial communities of impacted and non impacted soils was found, but a decrease in bacterial richness was observed based on rarefaction analysis in samples with high concentrations (81-418 µg g-1 ) of lead (Pb). This study strongly points to the need for substantial efforts- starting with prevention measures and then the implementation of remediation technologies - to limit human-derived contamination impacts on the local environment and resident species and communities.