“Researchers have discovered a new strain of bacteria that can produce non-toxic, comparatively inexpensive “rhamnolipids,” and effectively help degrade polycyclic aromatic hydrocarbons, or PAHs — environmental pollutants that are one of the most harmful aspects of oil spills.
Because of its unique characteristics, this new bacterial strain could be of considerable value in the long-term cleanup of the massive Gulf Coast oil spill, scientists say.
More research to further reduce costs and scale up production would be needed before its commercial use, they added.
The findings on this new bacterial strain that degrades the PAHs in oil and other hydrocarbons were just published in a professional journal, Biotechnology Advances, by researchers from Oregon State University and two collaborating universities in China. OSU is filing for a patent on the discovery.
…The discovery is strain “NY3″ of a common bacterium that has been known of for decades, called 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,” technically, 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, which are usually derived from petroleum, are commonly toxic to health and ecosystems, and resist complete degradation.
Biosurfactants of various types are already used in a wide range of applications, from food processing to productions of paints, cosmetics, household products and pharmaceuticals. But they also have uses in decontamination of water and soils, with abilities to degrade such toxic compounds as heavy metals, carcinogenic pesticides and hydrocarbons.
Although the type of biosurfactant called “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.
Rhamnolipids are not toxic to microbial flora, human beings and animals, and they are completely biodegradable. These are compelling advantages over their synthetic chemical counterparts made from petroleum. Even at a very low concentration, rhamnolipids could remarkably increase the mobility, solubility and bioavailability of PAHs, and strain NY3 of P. aeruginosa has a strong capability of then degrading and decontaminating the PAHs.” …