1. Environmental molecular microbiology: molecular characterization of functioning genes and metagenomic diversity of microbes in remediation of pollutants including toxic metals (e.g., Hg) and organic pollutants, and in plant allelopathy. We are interesting in Hg methylation genes (hgcA and B), dissimilatory sulfite reductase genes (dsrAB) of sulfate reducing bacteria (SRB), and methyl-coenzyme M reductase genes (mcrA) of methanogens.
2. Mechanism studies of microbial Hg methylation and MeHg degradation: Hg methylation mechanisms by the methanogen, SRB, syntrophic association of methanogens with SRB, and iron reducing bacteria.
3. Fate and degradation pathway of stilbenoids as allelochemicals in microbial interactions with plants: fate and biodegradation mechanisms of stilbenoids such as resveratrol and pterostilbene and their ecological roles in plant-microbe and plant-fungi interactions.
4. Aquatic ecotoxicology and pollutant bioavailability: assimilation and transfer of Hg, MeHg, other heavy metals, and organic pollutants from bacteria or algae to micro-zooplankton or benthic amphipods (e.g., Hyalella azteca). Through trophic transfter, these toxicants might cause bioaccumulation and toxic effects on fishes and even aquatic mammals. Currently we are studying the residue effects of toxic metals and persistent organics in estuary dolphins.