| a novel lineage of proteobacteria involved in formation of marine fe-oxidizing microbial mat communities. | for decades it has been recognized that neutrophilic fe-oxidizing bacteria (feob) are associated with hydrothermal venting of fe(ii)-rich fluids associated with seamounts in the world's oceans. the evidence was based almost entirely on the mineralogical remains of the microbes, which themselves had neither been brought into culture or been assigned to a specific phylogenetic clade. we have used both cultivation and cultivation-independent techniques to study fe-rich microbial mats associated wit ... | 2007 | 17668050 |
| molecular comparison of bacterial communities within iron-containing flocculent mats associated with submarine volcanoes along the kermadec arc. | iron oxide sheaths and filaments are commonly found in hydrothermal environments and have been shown to have a biogenic origin. these structures were seen in the flocculent material associated with two submarine volcanoes along the kermadec arc north of new zealand. molecular characterization of the bacterial communities associated with the flocculent samples indicated that no known fe-oxidizing bacteria dominated the recovered clone libraries. however, clones related to the recently described f ... | 2009 | 19114513 |
| preliminary characterization and biological reduction of putative biogenic iron oxides (bios) from the tonga-kermadec arc, southwest pacific ocean. | sediment samples were obtained from areas of diffuse hydrothermal venting along the seabed in the tonga sector of the tonga-kermadec arc, southwest pacific ocean. sediments from volcano 1 and volcano 19 were analyzed by x-ray diffraction (xrd) and found to be composed primarily of the iron oxyhydroxide mineral, two-line ferrihydrite. xrd also suggested the possible presence of minor amounts of more ordered iron (hydr)oxides (including six-line ferrihydrite, goethite/lepidocrocite and magnetite) ... | 2009 | 19200145 |
| abundance of zetaproteobacteria within crustal fluids in back-arc hydrothermal fields of the southern mariana trough. | to extend knowledge of subseafloor microbial communities within the oceanic crust, the abundance, diversity and composition of microbial communities in crustal fluids at back-arc hydrothermal fields of the southern mariana trough (smt) were investigated using culture-independent molecular techniques based on 16s rrna gene sequences. seafloor drilling was carried out at two hydrothermal fields, on- and off-ridge of the back-arc spreading centre of the smt. 16s rrna gene clone libraries for bacter ... | 2009 | 19691504 |
| phylogeny of gammaproteobacteria. | the phylogeny of the large bacterial class gammaproteobacteria has been difficult to resolve. here we apply a telescoping multiprotein approach to the problem for 104 diverse gammaproteobacterial genomes, based on a set of 356 protein families for the whole class and even larger sets for each of four cohesive subregions of the tree. although the deepest divergences were resistant to full resolution, some surprising patterns were strongly supported. a representative of the acidithiobacillales rou ... | 2010 | 20207755 |
| functional diversity of bacteria in a ferruginous hydrothermal sediment. | a microbial community showing diverse respiratory processes was identified within an arsenic-rich, ferruginous shallow marine hydrothermal sediment (20-40 degrees c, ph 6.0-6.3) in santorini, greece. analyses showed that ferric iron reduction with depth was broadly accompanied by manganese and arsenic reduction and fes accumulation. clone library analyses indicated the suboxic-anoxic transition zone sediment contained abundant fe(iii)- and sulfate-reducing deltaproteobacteria, whereas the overly ... | 2010 | 20410934 |
| lithotrophic iron-oxidizing bacteria produce organic stalks to control mineral growth: implications for biosignature formation. | neutrophilic fe-oxidizing bacteria (feob) are often identified by their distinctive morphologies, such as the extracellular twisted ribbon-like stalks formed by gallionella ferruginea or mariprofundus ferrooxydans. similar filaments preserved in silica are often identified as feob fossils in rocks. although it is assumed that twisted iron stalks are indicative of feob, the stalk's metabolic role has not been established. to this end, we studied the marine feob m. ferrooxydans by light, x-ray and ... | 2010 | 21107443 |
| neutrophilic iron-oxidizing "zetaproteobacteria" and mild steel corrosion in nearshore marine environments. | microbiologically influenced corrosion (mic) of mild steel in seawater is an expensive and enduring problem. little attention has been paid to the role of neutrophilic, lithotrophic, iron-oxidizing bacteria (feob) in mic. the goal of this study was to determine if marine feob related to mariprofundus are involved in this process. to examine this, field incubations and laboratory microcosm experiments were conducted. mild steel samples incubated in nearshore environments were colonized by marine ... | 2010 | 21131509 |
| ultra-diffuse hydrothermal venting supports fe-oxidizing bacteria and massive umber deposition at 5000 m off hawaii. | a novel hydrothermal field has been discovered at the base of lōihi seamount, hawaii, at 5000 mbsl. geochemical analyses demonstrate that 'femo deep', while only 0.2 °c above ambient seawater temperature, derives from a distal, ultra-diffuse hydrothermal source. femo deep is expressed as regional seafloor seepage of gelatinous iron- and silica-rich deposits, pooling between and over basalt pillows, in places over a meter thick. the system is capped by mm to cm thick hydrothermally derived iron-o ... | 2011 | 21544100 |
| high-resolution 2d and 3d cryo-tem reveals structural adaptations of two stalk-forming bacteria to an fe-oxidizing lifestyle. | aerobic neutrophilic fe-oxidizing bacteria (feob) thrive where oxic and iron-rich anoxic waters meet. here, iron microbial mats are commonly developed by stalk-forming fe-oxidizers adapted to these iron-rich gradient environments, somehow avoiding iron encrustation. few details are known about feob physiology; thus, the bases of these adaptations, notably the mechanisms of interactions with iron, are poorly understood. we examined two stalked feob: the marine zetaproteobacterium mariprofundus fe ... | 2011 | 21895918 |
| Mariprofundus ferrooxydans PV-1 the first genome of a marine Fe(II) oxidizing Zetaproteobacterium. | Mariprofundus ferrooxydans PV-1 has provided the first genome of the recently discovered Zetaproteobacteria subdivision. Genome analysis reveals a complete TCA cycle, the ability to fix CO(2), carbon-storage proteins and a sugar phosphotransferase system (PTS). The latter could facilitate the transport of carbohydrates across the cell membrane and possibly aid in stalk formation, a matrix composed of exopolymers and/or exopolysaccharides, which is used to store oxidized iron minerals outside the ... | 2011 | 21966516 |