URI researcher surveying microorganisms
in Rhode Island
Project helps document State's biodiversity
KINGSTON, R.I. -- September 21, 2000 -- Scientific efforts to identify, map and protect all of the creatures on Earth usually focus on higher order creatures like birds, mammals, reptiles and amphibians. Only recently have efforts been undertaken to include insects in these surveys.
In Rhode Island, attention is now being paid to microscopic organisms, too.
University of Rhode Island Professor Linda Hufnagel has launched the Rhode Island Cilioprotist Micrograzer Survey©, an effort to document the diversity and distribution of cilioprotists in the state. These single-celled microorganisms are found wherever there is water -- including soil, rain, and snow -- and are vitally important to the state's ecology.
Ciliates feed on bacteria, diatoms, phytoplankton and other microbes, and they then become food for larger aquatic and soil animals like copepods, worms, water fleas and shellfish. They play a key role in the decomposition process at sewage treatment plants, for instance and control blooms of potentially harmful bacteria and phytoplankton.
"Ciliates are also model systems for understanding how human cells work," explained Hufnagel, a resident of Narragansett. "They're an untapped resource of genetic information for various natural products. They've got unique proteins, toxins, enzymes and other compounds whose use to humans has not yet been explored."
Just one species of cilioprotist has been found to have a commercial use so far. Tetrahymena, a species that Hufnagel has studied extensively, is the source of an enzyme commonly used today in biotechnology labs to split RNA molecules.
The Rhode Island survey has identified more than 100 species of ciliates to date.
"There are probably 20,000 ciliate species worldwide -- maybe more -- and at least 1,000 in Rhode Island. But they're difficult to identify because even those that look alike can be quite different."
Some cilioprotists, says Hufnagel, are immortal. "They reproduce by periodically dividing and reorganizing their structure. So if they're treated well they can live forever."
Hufnagel is currently focused on searching for ciliates in coastal ponds, the Great Swamp, and in freshwater ponds that were carved out by glaciers.
"The Great Swamp is a unique habitat where ciliates have not been well documented. We already found one species there that's new to science, a large red ciliate that eats red algae," said Hufnagel. "It's likely that we'll find quite a few new species before we're finished."
According to Hufnagel, very few similar surveys of microscopic organisms are under way around the world. Back in the 1930s and '40s it was a rather common scientific practice, but it's become unpopular lately. Besides the Rhode Island project, researchers in Connecticut and Maryland are the only others doing so in the U.S., and these are not surveying an entire state.
Hufnagel and her students collect samples in the field and identify them under the microscope in her laboratory. They then input the information into a detailed database that includes the physical, geographical, behavioral, and environmental properties of each species identified. In addition, a videomicroscope is used to record movement and behavioral aspects of the organisms.
"They are highly motile organisms, and they have species-specific behaviors related to movement. So the videomicroscopy is an important element in the database."
Hufnagel plans to make the database accessible to users on CD-ROM and via the internet. She expects that it will be especially useful to "natural product prospectors" companies looking for a particular organism as well as researchers and school teachers.
"I hope the data could also be useful to town planners, so they'll know what organisms would be affected by various proposed uses of town lands and waters," she said.
Equally important, according to Hufnagel, the data she collects will give a more complete picture of the diversity of life in Rhode Island.
For Information: Linda Hufnagel 874-5914, Todd McLeish 874-7892