Identification of Boseongicola sediminum sp. nov., a Novel Decabromodiphenyl Ether (BDE-209)-tolerant Strain Isolated from Coastal Sediment in Xiamen, China.

Abstract

Polybrominated diphenyl ethers (PBDEs) are a group of aromatic organic bromine compounds, which have been used in a broad array of polymeric materials (plastics, foams, resins, and adhesives) as brominated flame retardants. They are used in commercial and household products, including textiles, electronic equipment, airplanes, and automobiles, especially in China and the USA, because they are inexpensive with excellent flameretardant effects. During the past decade, over 14,000 tonnes of PBDEs have entered the market, and have become ubiquitous environmental contaminants. Although they have been regulated in a wide variety of countries, decabromodiphenyl ether 209 (BDE-209), one kind of PBDE, is still used legally in most countries, and accounts for > 80% of PBDE usage worldwide, especially in China and the USA. Based on previous research, exposure to BDE209 significantly increases many kinds of health risk for humans. In the 2006 PBDE Project Plan, the US Environmental Protection Agency summarized animal studies of various commercial mixtures and individual congeners, which posed potential concerns about the liver toxicity, thyroid toxicity, developmental toxicity, and developmental neurotoxicity of BDE-209 in adult men. There is also growing evidence that prenatal or early-life exposure to PBDEs impairs neonatal neurodevelopment. Previous studies have also documented the relationships between serum PBDEs and reduced sperm motility and counts. Numerous physicochemical methods have been used to remediate environmental PBDE contamination, but these methods entail many problems, including complex operational procedures, high costs, and low efficiency, which restrict their application. Moreover, some of these methods may create secondary pollutants that are even more harmful to the environment. Although few studies have reported techniques for eliminating PBDE contamination, treating environmental pollutants (such as chromium, benzene, and anthracene) with microorganisms has been shown to be an effective method, with the advantages of practicability, environmental friendliness, and cost-efficiency. The BDE-209-tolerant bacterial strain TAWCT132 is a novel species in the genus Boseongicola, a member of the order Rhodobacterales. The genus Boseongicola contains only one species at present, Boseongicola aestuarii, which was isolated from a tidal flat sediment at Boseong, South Korea. B. aestuarii is Gram negative, aerobic, nonmotile, and pleomorphic (coccoid, ovoid, or rod-shaped). In this study, we determined the specific taxonomic characterization of TAW-CT132, which was isolated from offshore sediment samples in an area of PBDEscontaminated sea in Tong’an Bay, Xiamen City, PR China and evaluated the efficiency of its degradation of BDE-209. This study expands the microbial resources available for the treatment of BDE-209 contamination, and lays a theoretical foundation for investigating the degradation mechanism/s of TAWCT132. Sediment samples were collected on April 8,