Searching for previously unknown toxins, potential medicines in Lake Erie cyanobacteria blooms

July 30, 2019
Contact: Greg Dick,
David Sherman

ANN ARBOR—University of Michigan researchers are collecting and analyzing samples from this summer’s Lake Erie cyanobacteria bloom to discover and characterize previously unknown toxins that may threaten human health, as well as compounds that could serve as sources of new medicines.

The project is led by U-M microbiologist and oceanographer Greg Dick and David Sherman, a professor of medicinal chemistry who studies natural chemical compounds made by microorganisms.

The study is part of the new Great Lakes Center for Fresh Waters and Human Health, which is led by Bowling Green State University and was founded last year with a $5.2 million federal grant.

“Our role is to apply techniques in environmental genomics and the biochemistry of natural products to study Lake Erie cyanobacterial blooms in order to identify new toxins, and also compounds that are of potential use for medicine,” said Dick, an associate professor in the U-M Department of Earth and Environmental Sciences.

The cyanobacterium Microcystis is commonly found in Lake Erie algal blooms and produces a class of toxins called microcystins that pose a threat to human and animal health. More than 50 microcystins have been discovered worldwide to date, and other forms of the toxin may exist but have evaded detection.

The U-M project will identify the genes responsible for the production of previously unknown toxins—both microcystins and other microbial toxins—in Lake Erie cyanobacterial blooms, as well as bioactive compounds that could be targeted for further study as potential disease treatments.

“DNA will be isolated, sequenced, assembled from samples and analyzed by Greg’s group. This will tell us what types of microbes are present and how the bloom composition changes over the course of the summer and fall,” said Sherman, a research professor at U-M’s Life Sciences Institute.

“My group will determine the complexity of known microcystin toxins and identify new toxins. Together, we hope to understand how blue-green algae blooms change over time, the parameters that may impact toxin production, the source of the toxins and the mechanisms behind any changes that we observe.”

Other U-M researchers involved in the study include Colleen Yancey, Ashu Tripathi and Fengan Yu. New equipment obtained from U-M’s Natural Products Biosciences Initiative will be used in the project.

Dick also led a multidisciplinary study of western Lake Erie’s shifting cyanobacterial communities that began in May 2014 with funding from the U-M Water Center. U-M researchers who remain active in that effort and related studies include Rose Cory, George Kling, Vincent Denef and Melissa Duhaime, along with collaborators at the U-M based Cooperative Institute for Great Lakes Research and the National Oceanic and Atmospheric Administration’s Great Lakes Environmental Research Laboratory in Ann Arbor.


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