Marine microbes make a meal of oil.

Hundreds of millions of litres of petroleum enter the environment from both natural and anthropogenic sources every year. The input from natural marine oil seeps alone would be enough to cover all of the world's oceans in a layer of oil 20 molecules thick. That the globe is not swamped with oil is testament to the efficiency and versatility of the networks of microorganisms that degrade hydrocarbons, some of which have recently begun to reveal the secrets of when and how they exploit hydrocarbons as a source of carbon and energy

The genus Piscirickettsia

The genus Piscirickettsia is part of the Piscirickettsiaceae family, belonging to the Gammaproteobacteria class within the Thiotrichales order. The family contains seven phylogenetically related genera (Cycloclasticus, Hydrogenovibrio, Sulfurivirga, Thioalkalimicrobium, Methylophaga, Thiomicrospira, and Piscirickettsia), with highly diverse characteristics, making them very different from one another. The genus Piscirickettsia comprises a single species called Piscirickettsia salmonis, a Gram-negative facultative intracellular fish pathogen that significantly affects the salmon industry. Since its first isolation in Chile in 1989, the bacterium has been reported in Norway, Scotland, Greece, Canada, and the USA, among others. To date, the complete genome sequence of P. salmonis has not been reported, and relevant aspects of its metabolism, virulence, and life cycle are still poorly understood