Bacteria on the Great Barrier Reef Hold Health Secrets

TOWNSVILLE, Queensland, Australia, February 6, 2002 (ENS) –

Out on the world's largest reef, tropical marine bacteria can adapt to ultraviolet light in a way that may help scientists decode a vital process of aging. The man who discovered this phenomenon, Dr. Walt Dunlap, is a marine specialist who also found that tropical corals produce their own sunscreen. Dr. Dunlap at the Australian Institute of Marine Science, in collaboration with Professor Yorihiro Yamamoto at the University of Tokyo, has now discovered an enzyme adaptation that may one day enable humans to enjoy greater health in old age.

Shallow water corals (Photo courtesy Australian Institute of Marine Science (AIMS)) In studying the effects of ultraviolet radiation on marine organisms, researchers found that bacteria living in the surface mucus of shallow water corals increase levels of the powerful antioxidant form of coenzyme Q.

The discovery is unique and holds promise for human health, because scientists believe that aging and age related degenerative diseases are progressed by our diminishing ability to maintain adequate antioxidant levels of coenzyme Q, according to Theresa Millard at the Australian Institute of Marine Science.

In the free radical theory of aging, coenzyme Q, available in bottles without prescription on pharmacy shelves, is one of the most potent antioxidants working to destroy free radicals. These toxic by-products are created by cells as they burn calories.On his latest trip to the nearby Great Barrier Reef during the austral mid-summer month of January, Dr. Dunlap found bacteria that increased the antioxidant activity of coenzyme Q more than fivefold, 565 percent, under ultraviolet activation.

The results have confounded his expectation that the stress of ultraviolet radiation would cause a decrease in the antioxidant levels of coenzyme Q. Instead, Dr. Dunlap said, the bacteria cells are overcompensating for UV exposure, and show dramatic increases in the active form of the antioxidant. These findings were reported to the joint scientific meeting of the Japan and Australasian Societies for Free Radical Research, held in Sydney November 30 to December 4, 2001.

Dunlap and Yamamoto propose the use of this adaptation in the metabolism of marine bacteria as a model to probe cellular regulation of the same function in humans. Branching coral (Photo by Dr. Lyndon Devantier courtesy AIMS)

“Genetics has established a close evolutionary link between bacteria and mitochondria [the energy powerhouse of human cells],” said Dr. Dunlap. “Therefore we propose utilizing this discovery to explore common metabolic pathways of antioxidant defence for human benefit,” he said. Dr. Dunlap is recognized as a world leader in the field of marine ultraviolet photobiological chemistry; his research spans the globe from tropical coral reefs to the frozen oceans of Antarctica under the ozone hole.

During his explorations of the Great Barrier Reef, Dr. Dunlap discovered the sunscreen creating capacity of reef building corals that are exposed to high levels of potentially damaging solar radiation. He found that many marine organisms biosynthesize, or diet accumulate, UV-absorbing compounds - sunscreens – for environmental light protection.

The new class of sunscreens has been patented by the Australian Institute of Marine Science, and commercial activities are being negotiated with a Sydney based investor group for Australian and international markets.

Dr. Dunlap's new coenzyme Q experiments may also eventually lead to a commercial product.