ANAEROBIC MICROBIOLOGY. Regulation of gene expression in methane-producing Archaea - Osmoregulatory mechanisms in marine and halophilic species of microorganisms - Anaerobic bioremediation in the marine environment.

Biology of Methanogenesis and Anaerobic Bioremediation
Regulatory pathways in the methanogenic Archaea with emphasis on catabolic gene expression; mechanisms of anaerobic reductive dechlorination in sediments impacted by PCBs and other organochlorianes; bioprocess scale-up of microorganisms from extreme environments.

Research interests

Regulatory pathways in the methanogenic Archaea

The Archaea, Bacteria and Eucarya represent the three primary phylogenetic lineages that diverged and evolved from a common progenote. The controlled expression of gene products involved in methanogenesis is essential for complete biomass conversion and bioremediation in anaerobic sediments, however, the mechanisms of catabolic gene regulation in the third lineage, the Archaea, is not yet known. The goal of this project is use genetic approaches combined with genomics and proteomics to determine whether gene expression in the Archaea functions by mechanisms that are analogous to the other two lineages, Bacteria and Eucarya, or by mechanisms that are unique to this phylogenetic line. Regardless of which mechanism(s) is revealed by this investigation, the results will provide further insight into the global molecular strategies of gene regulation. This research is divided into three projects: 1) mechanisms of gene transcription; 2) global regulatory pathways for methanogenesis; 3) bioprocess scale-up of archaeal proteins. For more details, go to the Sowers' Lab Homepage.

Microbial Reductive Dechlorination of Organochlorines

Coastal anaerobic sediments are the ultimate global sinks for accumulation of chlorinated hydrocarbons such as polychlorinated biphenyls (PCBs) where reductive dehalogenation may have a significant role in their biotransformation. Understanding this microbial process is critical for making management decisions concerning both remediation and risk assessment of PCB-impacted coastal regions. Our lab and collaborators have for the first time identified two PCB dechlorinating microbes and based on this discovery developed molecular ribosomal probe assays, which are currently being optimized for detection of PCB dechlorinating catalysts in selected coastal sediments. Results of these studies will provide fundamental information on the biocatalytic processes required to develop bioremediation strategies and promote intrinsic PCB transformation in impacted marine harbor sediments and dredge deposition sites. In addition to the bioremediation implications, the investigations proposed here will expand our understanding of the organismal and metabolic biocomplexity that is potentially available for dehalogenation processes in coastal sediments. This research is divided into three projects: 1) gene probe assessment of PCB dechlorinating potential; 2) proteomics and biochemistry of microbial dehalogenation; 3) ecology of the global chlorine cycle.

For more detatils, go to the Sowers' Lab Homepage.