Hidden in plain sight: discovery of sheath-forming, iron-oxidizing Zetaproteobacteria at Loihi Seamount, Hawaii, USA (pages 116–127)
Emily J. Fleming, Richard E. Davis, Sean M. McAllister, Clara S. Chan, Craig L. Moyer, Bradley M. Tebo and David Emerson
Version of Record online: 15 APR 2013 | DOI: 10.1111/1574-6941.12104
Microbial mats are commonly found in habitats characterized by steep gradients of redox-active substrates. Deep-sea hydrothermal vents, both at spreading ridge axes and seamounts, support microbial mat communities that take advantage of gradients of inorganic, redox-active compounds in the vent fluids and oxygen in the surrounding ocean. Lithotrophic iron-oxidizing bacteria form microbial mats at focused flow or diffuse flow vents in deep-sea hydrothermal systems where Fe(II) is a dominant electron donor. The study findings suggest that effective growth on Fe(II) by iron-oxidizing bacteria in circumneutral redox boundary environments requires a unique degree of morphological and physiological specialization that has evolved separately in marine and freshwater ecosystems. The results constitute the discovery of a novel group of marine sheath-forming iron-oxidizing bacteria.