Shewanella piezotolerans WP3

Shewanella are facultatively anaerobic, Gram-negative bacteria, motile by polar flagella, rod-like, and generally associated with aquatic or marine environments. They are capable of using a variety of compounds as electron acceptors, including oxygen, iron, manganese, uranium, nitrate, nitrite, fumarate, to name but a few. This ability makes Shewanella important for bioremediation of contaminated metals and radioactive wastes. The genus Shewanella comprises 36 recognized and hundreds of uncharacterized cultivable species.Shewanella piezotolerans WP3, a piezotolerant and psychrotolerant iron reducing bacterium was isolated from a western Pacific Ocean sediment sample located at a water column depth of 1,914 m. It grows optimally at 15-20 degrees C and with a broad pressure optimum extending from atmospheric pressure to about 20 MPa. It possesses numerous genes or gene clusters which help it to cope with extreme living conditions such as genes for two sets of flagellum systems, structural RNA modification, eicosapentaenoic acid (EPA) biosynthesis and osmolyte transport and synthesis. And WP3 contains 55 open reading frames encoding putative c-type cytochromes which are substantial to its wide environmental adaptation ability. The mtr-omc gene cluster involved in the insoluble metal reduction in the Shewanella genus was identified and compared. The two sets of flagellum systems were found to be differentially regulated under low temperature and high pressure; the lateral flagellum system was found essential for its motility and living at low temperature (adapted from PubMed 18398463). (HAMAP: SHEPW)