| Description: |
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 loihica , formerly Shewanella sp. strain PV-4, was isolated from iron-rich microbial mats at an active, deep sea, hydrothermal Naha Vent (1325 m below sea level), located on the South Rift of Loihi Seamount, Hawaii. PV-4 is an orange colour, psychrotolerant, capable of reducing metals at temperatures from 0 to 37 degrees C, and has a temperature optimum of 18 degrees C. Growth is observed in a salinity range of 0.05 to 5%. Metal reduction is observed at pH 7.0-8.9, while growth is observed in a pH range of 5.5 to 10 aerobically. The electron donors lactate, formate, pyruvate as well as hydrogen can be utilized with a reduction of Fe(III)-citrate, Mn(IV)-oxide, Co(III)-EDTA, Cr(VI), and U(VI). The strain can not use acetate as an electron donor. PV-4 produces single domain magnetite at temperatures from 14 to 37 degrees C (adapted from http://genome.jgi-psf.org/draft_microbes/she_p/she_p.home.html). |