The second largest group of the community was affiliated to the Gammaproteobacteria, mainly to members of the genus Pseudomonas. The most abundant Pseudomonas clones showed 100% 16S rRNA gene similarity to the Ps. veronii/extremaustralis lineage. Ps. veronii is known to degrade a wide variety of aromatic compounds; however, it was observed that hypoxia can decrease its degrading ability [5,20].