Final Progress Reports: Michigan State University: Molecular Insight into Dioxin Degradation by Microbes and Microbial Communities

Superfund Research Program

Molecular Insight into Dioxin Degradation by Microbes and Microbial Communities

Project Leader: Gerben J. Zylstra (Rutgers University)
Grant Number: P42ES004911
Funding Period: 2013-2021

Final Progress Reports

Year:   2020 

The ability of microbes to degrade dioxin is not well understood. Only a few organisms in pure culture are known to degrade dioxin. The research team has taken a multidisciplinary approach to analyze Sphingomonas wittichii (RW1’s) ability to completely metabolize the carbon skeleton of dibenzo-p-dioxin. Researchers determined that the ability of RW1 to degrade dioxin requires catabolic pathway genes encoded by both the chromosome and the large catabolic plasmid pSWIT02. Using a combination of genomic and genetic tools, the team has also identified non-metabolic pathway genes encoding enzymes that may enhance the ability of RW1 to degrade dioxin. The project has determined RW1’s ability to degrade dioxin adsorbed to clays and activated carbon (biochars), all of which will lead to enhanced remediation efforts. The lab has isolated new strains capable of degrading dibenzofurans and dioxins from Superfund sites. Technologies are being developed to analyze dioxin-like genes in the environment and to analyze the metagenome of various soil communities, including those enriched for dioxin degraders.