environmental microbiology, biodegradation of environmental contaminants, microbial carbon cycling, molecular tools for microbial ecology, metagenomics, biological hazardous waste treatment, bioremediation of groundwater pollutants such as PCE, TCE, DCE, VC, TCA, DCA, MTBE, BTEX, PBDEs, NDMA, Dioxane, PFOS, PFOA, fire-fighting foams