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An OSU veterinarian has gone to extremes to find microbes that break down pollutants like crude oil.

He’s no latter day Jonah, but Morrie Craig does have something in common with the Old Testament hero. The biblical Jonah, you will remember, spent 40 days in the belly of a whale, certainly enough time to become thoroughly familiar with whale digestion. Craig knows a lot about whale stomachs too, although he never camped out in one. The Oregon State University veterinary medicine researcher began investigating the contents of whale bellies back in 1993 in search of bacteria that could be used for biodegradation.

Biodegradation is the name of a process in which bacteria break down the molecular structure of chemical compounds. It’s the core of a new technology called bioremediation. Craig is searching for bacteria that can break down the chemical components of crude oil and gasoline.

He got involved in this area of research in the mid-1970s when a weed called tansy ragwort was identified as a major threat to grazing livestock in the Pacific Northwest. Cattle that consumed the weed died in a matter of days from liver failure caused by toxic substances in the plant called pyrrolizidine alkaloids.

Two men standing with a sheep.

OSU veterinarian Morrie Craig, with student Anita Jordahl, discovered that bacteria in sheep’s stomachs neutralize a toxin in the tansy ragwort plant. This peaked Craig’s curiousity about the neutralizing powers of bacteria in creatures with similar digestive systems. Photo: Bob Rost

But sheep, like cattle a grazing animal (or ruminant) with multiple stomach chambers for digesting plants, did not die when they ate tansy. Research revealed that bacteria, or microbes, in the sheep’s gut interacted with the molecules of the toxin and altered them chemically, converting the toxin into a harmless organic compound.

“Cattle have the same microbes in their gut, but at much lower levels than in sheep,” said Craig. “This kept the cattle from breaking down enough of the tansy toxin in a timely manner to prevent liver damage.”

Armed with this finding, he experimented with putting alkaloid-busting bacteria from sheep into cattle. The bacteria protected the animals from tansy ragwort poisoning—and opened Craig’s eyes to a much larger world of possibilities.

“There are from 500 to 1,000 types of microbes in the average ruminant animal’s stomach,” he said. “Very little is known about these microbes because to date, researchers have not paid a great deal of attention to them. That is changing now.”

A calf in a meadow.

Tansy ragwort injures and sometimes kills Oregon cattle. Photo: Tom Gentle

From the toxic alkaloids in tansy ragwort, his research focus shifted to trinitrotoluene, also known as TNT.

“The Office of Naval Research heard about one of our grant proposals for funding the research with sheep microbes and suggested that we attempt biodegradation of TNT,” said Craig.

Trinitrotoluene has been used in the manufacture of bombs and other explosives for the U.S. military since the World War II era. This has caused extensive TNT contamination at those manufacturing sites. Prolonged contact with TNT is known to present significant health risks. The military is looking for a cost-effective way to clean up TNT-contaminated sites in the United States and overseas.

“There are estimates that to clean up all the TNT contamination at U.S. military bases here and around the world would cost $50 billion, so there is a very big economic incentive to look at that compound,” Craig said.

While he was absorbed with finding bacteria to break down TNT, serendipity intervened, steering him and his research program toward Alaska’s North Slope and the whales of that region’s Arctic waters.

A whale deep in the ocean.

A bowhead whale. Photo: Flip Nicklin

Craig was in Alaska in the winter of 1992 running a drug testing program for the world-famous Iditarod sled dog race. While talking with some Inupiat Eskimos who were racing in the Iditarod, he mentioned his research with bacteria. He remarked that whales, because of digestive similarities to sheep, might be a possible source of bacteria that would be useful in breaking down crude oil, an ocean pollutant.

The Inupiats surprised Craig by inviting him on a whale hunt, giving the researcher an opportunity to get up close and personal with whale guts.

Whales evolved from terrestrial animals millions of years ago, so it is no surprise that they are similar to some land animals. Craig’s interest in the bowhead and right whales hunted by the Inupiats stemmed from the fact that both are ruminants, like sheep, with multiple chambers in their stomachs.

Not all whales fall into this category. Sperm and beluga whales, for example, are monogastric, meaning they have a single-chambered stomach. Humans also are monogastric.

A whale lying in the snow surrounded by people.

Alaskan Eskimos are the world’s only legal hunters of bowhead whales like this one. They use traditional techniques and their annual quota is 41. OSU’s Morrie Craig, and many other scientists, often visit harvest sites to study the animals. Photo: Flip Nicklin, Minden Pictures

Craig’s speculation was much more than a hopeful shot in the dark. He was aware of oceanographic studies suggesting baleen whales, which feed on tiny shrimplike creatures called krill by filtering sea water through a bony sieve in their mouths, were somehow immune to cancers.

“There are many carcinogenic chemicals in sea water and fish, and other sea creatures ingest these chemicals as they feed,” he said. “Predictably, the carcinogens take a certain toll, causing many sea animals to develop cancers. Whales are no exception to this risk. However, oceanographers began to notice that not all whales suffered equally from the various cancers caused by carcinogens in the food chain.”

Researchers frequently observed cancers in toothed whales, but not in baleen whales. Craig reasoned that the baleen whales’ low incidence of cancer, even though they eat vast amounts of polluted krill daily, might be the result of bacteria in their guts breaking down the carcinogens to harmless compounds. The only way to be sure was to check the contents of some baleen whale bellies.

Craig has journeyed north to Alaska in the late spring the last two years to follow the annual whale hunts on the North Slope. Initially, he conducted field work with microbiologist Jane Leedle of Kansas State University. Currently he is working with Colin Orpin, a microbiologist from Cambridge University in England.

“We cooperate with Inupiats Eskimos on the North Slope who still hunt whales the way their ancestors have for centuries,” Craig said.

By agreement with the International Whaling Commission, Alaska Eskimos are allowed to harvest a small number of whales using their traditional hunting techniques. They locate a whale feeding on krill just off the ice shelf, harpoon it and drag it onto the ice where they harvest it.

“When the Inupiats take a whale they report it by radio,” Craig explained. “Then we travel to the site and collect samples from the whale’s fore-stomach, the first of three chambers in the animal’s gut.”

After returning to a field lab in Point Barrow, Craig and co-workers inject fluid samples into bottles containing various chemical toxins and components of crude oil.

Man in a lab working on a small machine.

Craig, in his OSU lab, checks a pollutant treated with bacteria from a whale. Photo: Bob Rost

“Each bottle acts as an artificial rumen,” he said.

The researchers check the bottles according to a time schedule to measure what effect, if any, the bacteria have on the toxins.

“We’re trying to get isolates or enrichments of the microbes from the whale fore-stomach that break down the toxins we’re testing, such as BTEX (benzene, toluene, xylene and ethylbenzene), which are components of gasoline; anthracene, fluorene and naphthalene, components of crude oil; and atrazine, a component of many pesticides,” Craig said.

Craig is also conducting research with biodegradation of ergovaline, a toxic alkaloid produced by a fungus that is widespread in grass seed crops in the Willamette Valley. The work on ergovaline is especially important in Oregon because this plant toxin is commonly found in grass seed straw.

“The gradual phaseout of field burning in the Willamette Valley has left grass seed growers with a huge straw disposal problem,” said Craig. “A lot of this material is now being used for cattle feed, but the ergovaline in the straw presents a danger to animals consuming it. Finding microbes that will degrade this toxin may ease this problem considerably.”

But let’s get back to Alaska.

“After we identify isolates of the bacteria we’re looking for, we ship them from the Point Barrow lab back to OSU, where they are produced in quantity for further testing,” Craig said.

Three researchers in the snow, wearing snowsuits.

Morrie Craig in Alaska with technicians Lynnette Perrine, left, and Maureen Chrysler. Photo: Jeff Schultz

“We are fortunate to have lab space for our field work at the old Arctic Naval Research Unit in Point Barrow, courtesy of the North Borough Department of Wildlife Management,” Craig added. “Our lab and living quarters are located in some quonset huts that aren’t bad at all by Northern Alaska standards, but really quite primitive by Corvallis standards.”

Although Craig’s Alaska work isn’t exactly a nail-biting adventure out of “The Call of the Wild,” it is difficult and the environment frigid.

“We don’t mush across the snow and ice with sled and dog team,” he noted. “Actually we have snowmobiles that work quite well, and often we are able to fly to the sampling site. But the distances from Point Barrow to many of the sites may be up to 400 miles, which makes for long working days. And bulky, cold-weather clothes are an absolute requirement.”

Since sampling his first whale stomach in 1993, he’s probably spent more time with whale innards than anyone—except maybe his Inupiat friends. Before it’s over, Morrie Craig may rival Jonah. And the world’s oceans, military bases and livestock may be the better for it.

Published in: Innovations, People