Tropical marine bacteria may slow ageing

Dr Walt Dunlap at the Australian Institute of Marine Science, in collaboration with Professor Yorihiro Yamamoto at the University of Tokyo, has discovered an enzyme adaptation that may one day enable humans to enjoy greater health in old age.

In studying the effects of ultra-violet radiation on marine organisms, researchers found that bacteria living in the surface mucus of shallow-water corals dramatically increase levels of the powerful antioxidant form of coenzyme Q.

In the free radical theory of ageing, coenzyme Q is one of the most potent antioxidants working to destroy free radicals toxic by-products that cells create as they burn calories.

On his latest trip to the Great Barrier Reef during January, Dr Dunlap found bacteria that increased the antioxidant activity of coenzyme Q more than fivefold (565%) under UV activation.

The results have confounded his expectation that UV-stress would cause a decrease in the antioxidant levels of coenzyme Q. Instead, the bacteria cells are over-compensating for UV exposure, and show dramatic increases in the active form of the antioxidant.

The discovery is unique and holds promise for human health since scientists believe ageing and age-related degenerative diseases are progressed by our diminishing ability to maintain adequate antioxidant levels of coenzyme Q.

Drs Dunlap and Yamamoto propose the use of this adaptation in the metabolism of marine bacteria as a powerful model to probe cellular regulation of this important function in humans. "Genetics has established a close evolutionary link between bacteria and mitochondria [the energy powerhouse of human cells]," said Dr Dunlap. "Therefore we propose utilising this discovery to explore common metabolic pathways of antioxidant defence for human benefit," he said.