Superfund Research Program
Microbial Communities that Bioremediate Chemical Mixtures
- Project Summary
The Microbial Communities that Remediate Chemical Mixtures Project focuses on advancing the research team's fundamental understanding of microbial communities involved in bioremediation of sediment and groundwater. The main contaminants of the team’s focus are arsenic and trichloroethene (TCE). For arsenic remediation, the team is perusing both enrichment cultures and a big data approach. The researchers are mining large sequence datasets to identify microorganisms capable of modifying arsenic. The researchers will then combine metadata associated with the aforementioned datasets to synthesize a model that can predict the potential reaction of microbial communities to arsenic perturbations. For TCE, the work is focused on defined consortia and communities containing Dehalococcoides mccartyi exposed to both TCE and arsenic. In addition, the researchers are developing important genetic tools (CRISPR-CAS9) that can be applied to bacterial consortia containing Desulfovibrio vulgaris Hildenborough (DvH) used to elucidate microbial interactions. This year, the researchers worked on aims one-three in parallel. As part of aim one, the researchers continued their big-data analysis to uncover >1000 potential functional variants of arsenic-related operons. These putative arsenic-operons were discovered in nearly all lineages of the bacterial and archaeal tree of life. The team is now using machine learning to examine the relation between phylogeny, environment and arsenic operons. For aim 2 the researchers characterized TCE induced growth inhibition on Desulfosporosinus auripigmenti, with and without the presence of D. mccartyi. For aim three the researchers investigated the changes in gene expression of D. mccartyi and DvH under differing arsenic concentrations. The researchers detected both upregulated and downregulated genes in both bacteria and are continuing to investigate their function. The team has also made great advances in applying CRISPR editing to DvH. The researchers were able to heterologously express genes from D. maccrtyi in DvH and are now doing the same with arsenic related genes.