Bacteria in Lake Huron sinkholes may hold keys to new cancer treatments, antibiotics

By Sarah Coefield
coefield@msu.edu
Great Lakes Echo
July 16, 2009

The colorful cyanobacteria coating the sinkholes in Lake Huron may be ancient, but researchers are hoping they will provide new medicines for cancer and infection treatments. Cyanobacteria produce a plethora of complex molecules. Researchers at the National Oceanic and Atmospheric Administration asked Dave Sherman to take a look at the bacteria to see if he could find any hints of medical applications. He did. Sherman, the Hans W. Vahlteich Professor in the Life Sciences Institute in the department of Medicinal Chemistry at the University of Michigan, studies chemicals produced by microbial organisms and looks for molecules that can fight cancer and infection.

Sinkhole backgrounder

Additional information about Lake Huron sinkholes

The Lake Huron Sinkholes Overview

El Cajon Sinkhole

Middle Island Sinkhole

Isolated Sinkhole

Glossary of terms and concepts
The Lake Huron Sinkholes

This map shows the locations of three sinkholes scientists are studying in northern Lake Huron.  The gray area is Michigan and the color gradient represents lake depth. Sinkholes and caves are karst formations created when mildly acidic rain and groundwater dissolve calcium carbonate in the limestone, carving tunnels and holes into the rock. The sinkholes in Lake Huron were most likely formed thousands of years ago, before the formation of the Great Lakes but after glaciers retreated.  When the Pleistocene glaciers retreated 10,000 years ago, they scraped the landscape clean of any older karst formations.  As a result, karst formations in the Great Lakes region formed between 10,000 and 8,000 years ago when low lake levels exposed the limestone bedrock. The sinkholes in Lake Huron range in diameter from a tabletop to a football field. They lie both near the shoreline and in the deeper waters.

Lake Huron sinkholes give clues to ancient life

By Sarah Coefield
Coefield@msu.edu
Great Lakes Echo
July 15, 2009

The scientists studying the Lake Huron sinkholes know the colorful bacteria they host have a prehistoric ancestry, but a major question remains: Where did it all come from? The purple cyanobacteria mats in the Lake Huron sinkholes resemble mats found in ice-covered Antarctic lakes.  Bopi Biddanda, a research scientist with the Grand Valley State University Annis Water Resources Institute, suspects they may have a similar ancestry.  This suspicion relies on a theory that microbial life is already distributed across the planet, and comes out of hiding when conditions are just right, he said. The Lake Huron mats provide clues for how ocean and lake currents could have spread the bacteria.  Microbial gases in the sinkhole sediment force portions of the cyanobacteria mats to protrude like purple fingers pointing toward the lake’s surface.  The protrusions sometimes tear off and float away on the currents. “I think it is one of the ways (the bacteria) get distributed to other distant regions where groundwater may be coming out,” Biddanda said.  “And if they land there, they can populate with the same kind of microbes.” If the bacteria spread on currents, it likely happened long ago.  “We think they’re survivors of the past, that upon conditions returning to favorable conditions they were able to thrive and reestablish and keep going,” Biddanda said.

Special Report: Lake Huron sinkholes

Great Lakes Echo explores the exotic life of Lake Huron sinkholes off the coast of northeast Michigan. Lake Huron discovery is a window on the past and future: Lake Huron’s depths hide a colorful, ancient world that holds keys to the planet’s history and clues for new cancer treatments and antibiotics. Lake Huron sinkholes give clues to ancient life: The scientists studying the Lake Huron sinkholes know the colorful bacteria they host have a prehistoric ancestry, but a major question remains: Where did it all come from? Bacteria in Lake Huron sinkholes may hold keys to new cancer treatments, antibiotics: The colorful cyanobacteria coating the sinkholes in Lake Huron may be ancient, but researchers are hoping they will provide new medicines for cancer and infection treatments. Sinkhole background information: Profiles of the three Lake Huron Sinkholes, how sinkholes form, and a sinkhole glossary.

VIDEO: Lake Huron discovery is a window on the past and future

By Sarah Coefield, coefield@msu.edu
Great Lakes Echo
July 14, 2009

Lake Huron’s depths hide a colorful, ancient world that holds keys to the planet’s history and clues for new cancer treatments and antibiotics. The locals in Alpena have long known about sinkholes just offshore from their northeast Michigan community.  But it will take researchers several years to unravel the local diving spots’ mysteries. The story of the Lake Huron sinkholes and their exotic ecosystems begins on a ship.  While surveying shipwrecks in the Thunder Bay National Marine Sanctuary in 2001, Steve Ruberg and his colleagues were surprised to detect underwater basins 300 feet below the surface.  To their trained eyes, the basins looked like sinkholes. The discovery warranted further investigation. “Looking at the data and understanding what was going on, we actually came back and revisited the sites in 2003,” Ruberg said.  Ruberg is an engineer with the National Oceanic and Atmospheric Administration’s Great Lakes Environmental Research Laboratory and a project leader for the sinkhole research.