Scientists have discovered a new strain of bacteria that can help in cleaning up of the oil spill in the Gulf of Mexico. The bacteria 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.
The “NY3” bacteria has an “extraordinary capacity” to produce rhamnolipids that can help break down oil and then degrade some of its most serious toxic compounds.
The rhamnolipids, which is non-toxic to microbial flora, human beings and animals, can help degrade polycyclic aromatic hydrocarbons (PAHs), a carcinogenic and mutagenic compound released with the oil spill, Oregon State University (OSU) said in a statement.
The OSU is filing for a patent on the discovery made by researchers from OSU and two Chinese universities – the Xi’an University of Architecture and Technology and Nanjing Agricultural University, Xinhua reported.
“PAHs are a widespread group of toxic, carcinogenic and mutagenic compounds, but also one of the biggest concerns about oil spills,” said Xihou Yin, a research assistant professor in the OSU College of Pharmacy.
“Some of the most toxic aspects of oil to fish, wildlife and humans are from PAHs,” Yin said. “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 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.
Pseudomonas 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.
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.
“The real bottleneck to replacing synthetic chemicals with biosurfactants like rhamnolipid is the high cost of production,” Yin said. “Most of the strains of P. aeruginosa now being used have a low yield of rhamnolipid. But strain NY3 has been optimized to produce a very high yield of 12 grams per liter, from initial production levels of 20 milligrams per liter.”
According to experts, the rhamnolipids produced by NY3 strain appear to be stable in a wide range of temperature, pH and salinity conditions, and strain NY3 aggressively and efficiently degrades at least five PAH compounds of concern. It’s easy to grow and cultivate in many routine laboratory media, and might be available for commercial use in a fairly short time. Further support to develop the technology is going to be sought from the National Science Foundation.
“Compared to their chemically synthesized counterparts, microbial surfactants show great potential for useful activity with less environmental risk,” the researchers wrote in their report. “The search for safe and efficient methods to remove environmental pollutants is a major impetus in the search for novel biosurfactant-producing and PAH-degrading microorganisms.” [via Science Daily]