Aromatic hydrocarbon degradation genes from chronically polluted subantarctic marine sediments

Abstract

With the goal of identifying functional biomarkers associated with polycyclic aromatic hydrocarbon (PAH) biodegradation in chronically-polluted Subantarctic marine sediments, we amplified from environmental metagenomic DNA, cloned and sequenced gene fragments encoding dioxygenase enzymes associated with the biodegradation of these compounds. In this chapter, we describe and classify 22 different groups of dioxygenase genes identified in this environment, most of them presenting low to intermediate sequence similarities with previously described sequences (33 to 68% identity at the amino acid level). In addition, we show that two of these novel genes were present at high abundances in the sediments, suggesting that populations carrying these genes could have an important ecological role in the microbial community.