"PAHs are a widespread group of toxic, carcinogenic and mutagenic compounds, but also one of the biggest concerns about oil spills," said Professor Xihou Yin, a research assistant at the Oregon State University College of Pharmacy.

"Some of the most toxic aspects of oil to fish, wildlife and humans are from PAHs."

"They can cause cancer, suppress immune system function, cause reproductive problems, nervous system effects and other health issues."

"This particular strain of bacteria appears to break up and degrade PAHs better than other approaches we have available."

The discovery is strain 'NY3' of Pseudomonas aeruginosa.

It was isolated from a site in Shaanxi Province in China, where soils had been contaminated by oil.

P. aeruginosa is widespread in the environment and can cause serious infections, but usually in people with health problems or compromised immune systems.

However, some strains also have useful properties, including the ability to produce a group of biosurfactants called rhamnolipids.

A surfactant is a type of wetting agent that lowers surface tension between liquids –- but we recognize surfactants more commonly in such products as dishwashing detergent or shampoo.

Biosurfactants are produced by living cells such as bacteria, fungi and yeast, and are generally non-toxic, environmentally benign and biodegradable.

By comparison, chemical surfactants are usually derived from petroleum, are often toxic to health and ecosystems, and resist complete degradation.

Although rhamnolipids have been used for many years, the newly discovered strain, NY3, stands out for some important reasons.

Researchers said in the new study that it has an 'extraordinary capacity' to produce rhamnolipids that could help break down oil, and then degrade some of its most serious toxic compounds, the PAHs.

"The real bottleneck to replacing synthetic chemicals with biosurfactants like rhamnolipid is the high cost of production," Professor Yin said.

"Most of the strains of P. aeruginosa now being used have a low yield of rhamnolipid."

"But strain NY3 has been optimised to produce a very high yield of 12 grams per litre, from initial production levels of 20 milligrams per litre."

More research to further reduce costs and scale up production will be required before strain NY3 is adopted for commercial use.