High-quality draft genome sequence of strain AK4OH1, a gammaproteobacterium isolated from estuarine sediment.

strain AK4OH1 (= DSM 17993 = ATCC BAA-1233) is a microaerophilic bacterium isolated from sediment from the Arthur Kill intertidal strait between New Jersey and Staten Island, NY. is Gram-negative and belongs to the . Strain AK4OH1 was the first representative of its genus to be isolated for its unique coupling of the oxidation of aromatic acids to the respiration of selenate.

Draft Genome Sequence of "Candidatus Halobonum tyrrellensis" Strain G22, Isolated from the Hypersaline Waters of Lake Tyrrell, Australia.

We report the draft 3.675-Mbp genome sequence of "Candidatus Halobonum tyrrellensis" strain G22, a novel halophilic archaeon isolated from the surface hypersaline waters of Lake Tyrrell, Australia. The availability of the first genome from the "Candidatus Halobonum" genus provides a new genomic resource for the comparative genomic analysis of halophilic Archaea.

Assembly-driven community genomics of a hypersaline microbial ecosystem.

Microbial populations inhabiting a natural hypersaline lake ecosystem in Lake Tyrrell, Victoria, Australia, have been characterized using deep metagenomic sampling, iterative de novo assembly, and multidimensional phylogenetic binning. Composite genomes representing habitat-specific microbial populations were reconstructed for eleven different archaea and one bacterium, comprising between 0.6 and 14.

Complete genome sequence of Desulfurispirillum indicum strain S5(T).

Desulfurispirillum indicum strain S5(T) is a strictly anaerobic bacterium isolated from river sediment in Chennai, India. D. indicum belongs to the deep branching phylum of Chrysiogenetes, which currently only includes three other cultured species.

Xenorhodopsins, an enigmatic new class of microbial rhodopsins horizontally transferred between archaea and bacteria.

Based on unique, coherent properties of phylogenetic analysis, key amino acid substitutions and structural modeling, we have identified a new class of unusual microbial rhodopsins related to the Anabaena sensory rhodopsin (ASR) protein, including multiple homologs not previously recognized. We propose the name xenorhodopsin for this class, reflecting a taxonomically diverse membership spanning five different Bacterial phyla as well as the Euryarchaeotal class Nanohaloarchaea. The patchy phylogenetic distribution of xenorhodopsin homologs is consistent with historical dissemination through horizontal gene transfer.

De novo metagenomic assembly reveals abundant novel major lineage of Archaea in hypersaline microbial communities.

This study describes reconstruction of two highly unusual archaeal genomes by de novo metagenomic assembly of multiple, deeply sequenced libraries from surface waters of Lake Tyrrell (LT), a hypersaline lake in NW Victoria, Australia. Lineage-specific probes were designed using the assembled genomes to visualize these novel archaea, which were highly abundant in the 0.1-0.

Mercury speciation in marine sediments under sulfate-limited conditions.

Sediment profiles of total mercury (Hg) and monomethylmercury (MMHg) were determined from a 30-m drill hole located north of Venice, Italy. While the sediment profile of total Hg concentration was fairly constant between 1 and 10 m, that of the MMHg concentration showed an unexpected peak at a depth of 6 m. Due to the limited sulfate content (<1 mM) at the depth of 6 m, we hypothesized that the methylation of inorganic Hg(II) at this depth is associated with the syntrophic processes occurring between methanogens and sulfidogens.

Desulfurispirillum indicum sp. nov., a selenate- and selenite-respiring bacterium isolated from an estuarine canal.

Strain S5(T), a novel bacterium that was isolated for its capability to respire selenate to elemental selenium, is described. In addition to selenate respiration, it was also capable of dissimilatory selenite, arsenate and nitrate reduction with short-chain organic acids such as pyruvate, lactate and acetate as the carbon sources and electron donors. The isolate was unable to grow fermentatively.

Pelobacter seleniigenes sp. nov., a selenate-respiring bacterium.

Strain KM(T) is a novel bacterium with the unique metabolic abilities of being able to respire selenate as the electron acceptor using acetate as the carbon substrate and possessing the ability to grow fermentatively on short-chain organic acids such as lactate, citrate and pyruvate. Strain KM(T) was isolated from a sediment enrichment culture of a highly impacted wetland system in New Jersey, USA. Strain KM(T) is able to reduce selenate as well as selenite to elemental selenium.

Identification of anaerobic selenate-respiring bacteria from aquatic sediments.

The diversity population of microorganisms with the capability to use selenate as a terminal electron acceptor, reducing it to selenite and elemental selenium by the process known as dissimilatory selenate reduction, is largely unknown. The overall objective of this study was to gain an in-depth understanding of anaerobic biotransformation of selenium in the environment, particularly anaerobic respiration, and to characterize the microorganisms catalyzing this process. Here, we demonstrate the isolation and characterization of four novel anaerobic dissimilatory selenate-respiring bacteria enriched from a variety of sources, including sediments from three different water bodies in Chennai, India, and a tidal estuary in New Jersey.

Sedimenticola selenatireducens, gen. nov., sp. nov., an anaerobic selenate-respiring bacterium isolated from estuarine sediment.

The respiration of selenate, as a terminal electron acceptor has been known for over a decade, but the microorganisms involved in this respiration are largely unknown. Here we characterize a novel selenate-respiring bacterium, strain AK4OH1, isolated from an estuarine sediment enrichment culture. Strain AK4OH1 has the unique capability to oxidize aromatic acids, such as benzoate, 4-hydroxybenzoate and 3-hydroxybenzoate, coupled to selenate respiration.