Primary Investigator: Thomas Niehaus
Co-Investigators: NA
Industry Partners: City of Minneapolis • Department of Public Works Division of Water Treatment & Distribution Services, Metropolitan Council Environmental Services (MCES)
Award Type: Seed Grant – Graduate Research Scholar


ProblemMetformin is one of the most prescribed drugs in use today, the dose is high (1-2.5 g/day) and only partly metabolized in most people, and it is fairly recalcitrant to biodegradation. Thus, it has become the most-prevalent anthropogenic environmental pollutant in surface waters and thousands of wastewater treatment plants (WTP) globally. There is evidence for endocrine disrupting activity in aquatic species and when chlorinated in WTPs, the resultant N-chloro species can be highly toxic to human cells. To protect Minnesotans, removal of these compounds from water must occur in WTPs.

Solution: This proposed research seeks to understand, and use, microbial consortia for effective metformin bioremediation. By sampling WTP sludge, we will isolate a pure culture bacterium capable of metformin degradation, sequence its genome, and identify genes/enzymes involved. We can then begin to correlate gene prevalence with metformin fate in WTPs and investigate factors contributing to metformin removal to develop improved bioremediation practices.

ImpactMetformin may be considered the number one anthropogenic pollutant in Minnesota, present in more than 1000 Minnesota waterways at orders of magnitude higher levels than other chemicals of concern. By studying naturally-occurring metformin-degrading bacteria, effective bioremediation strategies can be developed to remove this toxic contaminant from water in Minnesota and throughout the world. 

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