Structure of microbial communities and hydrocarbon-dependent sulfate reduction in the anoxic layer of a polluted microbial mat

► SRB accounted for > 17.5% of the total rRNA in the anoxic layer of a polluted microbial mat. ► SRB in the anoxic layer belonged to >8 genera and could grow on crude oil, toluene and hexadecane. ► Alkanes SRB degraders are numerically more abundant in the mats than aromatic degraders.