Genome Sequence of the Dioxin-Mineralizing Bacterium

Pollutants such as polychlorinated biphenyls and dioxins pose a serious threat to human and environmental health. Natural attenuation of these compounds by microorganisms provides one promising avenue for their removal from contaminated areas. Over the past 2 decades, studies of the bacterium Sphingomonas wittichii RW1 have provided a wealth of knowledge about how bacteria metabolize chlorinated aromatic hydrocarbons. Here we describe the finished genome sequence of S. wittichii RW1 and major findings from its annotation. The alphaproteobacterium Sphingomonas wittichii strain RW1 is known as a potent degrader of toxic dioxin pollutants, as it completely mineralizes the organic backbone of the dibenzo-p-dioxin structure (9, 10). This organism was isolated 2 decades ago for its ability to grow on dioxin-like compounds as the sole carbon and energy source (10). Since that time, research has shown that S. wittichii RW1 can transform a larger number and greater diversity of chlorinated diaryl ethers than any other known bacterium (5, 7, 9). The genome of S. wittichii RW1 was sequenced at th