Microbial activity is crucial for breaking down compounds, removing pollutants and chemically transforming organic compounds. Some of these pollutants are polycyclic aromatic hydrocarbons (PAHs) found in contaminated soils. The PAH phenanthrene, for example, can be broken down by the bacterium Arthobacterphenanthrenivorans, which was isolated from a creosote-polluted site in Greece, and used by the microbe as an energy source.
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Scanning electron micrograph of the bacterial strain of A. phenanthrenivorans.
(Image from Kallimanis A et al, SIGS 2011via CC 3.0 License)
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The microbe’s capacity for bioremediation applications led to its selection for sequencing by the DOE JGI. As reported in an article published last year, its complete genome was finished and annotated at the Institute.
Phenanthrene is used as a model for experiment biodegradation, and there are two known pathways for breaking down the compound. One of these involves a particular type of enzyme that has thus far been purified in just two microbial strains.
In the February 2012 issue of Applied and EnvironmentalMicrobiology, a team of researchers including DOE JGI Prokaryote Super Program Head Nikos Kyrpides described the results from purifying and analyzing two more of these enzymes from A. phenanthrenivorans. Having the genetic information from the same enzyme across multiple species allows researchers to conduct comparative studies, with the goal of developing microbial strains with improved PAH degradative abilities.