Impact of the Dimethyl Sulfoxide Reductase Superfamily on the Evolution of Biogeochemical Cycles.

The dimethyl sulfoxide reductase (or MopB) family is a diverse assemblage of enzymes found throughout and . Many of these enzymes are believed to have been present in the last universal common ancestor (LUCA) of all cellular lineages. However, gaps in knowledge remain about how MopB enzymes evolved and how this diversification of functions impacted global biogeochemical cycles through geologic time.

The microbial carbonate factory of Hamelin Pool, Shark Bay, Western Australia.

Microbialites and peloids are commonly associated throughout the geologic record. Proterozoic carbonate megafacies are composed predominantly of micritic and peloidal limestones often interbedded with stromatolitic textures. The association is also common throughout carbonate ramps and platforms during the Phanerozoic.

Discovery of Chlorophyll : Isolation and Characterization of a Far-Red Cyanobacterium from the Original Site of Manning and Strain (1943) at Moss Beach, California.

We have isolated a chlorophyll--containing cyanobacterium from the intertidal field site at Moss Beach, on the coast of Central California, USA, where Manning and Strain (1943) originally discovered this far-red chlorophyll. Here, we present the cyanobacterium's environmental description, culturing procedure, pigment composition, ultrastructure, and full genome sequence. Among cultures of far-red cyanobacteria obtained from red algae from the same site, this strain was an epiphyte on a brown macroalgae.

The physiology and evolution of microbial selenium metabolism.

Selenium is an essential trace element whose compounds are widely metabolized by organisms from all three domains of life. Moreover, phylogenetic evidence indicates that selenium species, along with iron, molybdenum, tungsten, and nickel, were metabolized by the last universal common ancestor of all cellular lineages, primarily for the synthesis of the 21st amino acid selenocysteine. Thus, selenium metabolism is both environmentally ubiquitous and a physiological adaptation of primordial life.

Microbial selenium metabolism: a brief history, biogeochemistry and ecophysiology.

Selenium is an essential trace element for organisms from all three domains of life. Microorganisms, in particular, mediate reductive transformations of selenium that govern the element's mobility and bioavailability in terrestrial and aquatic environments. Selenium metabolism is not just ubiquitous but an ancient feature of life likely extending back to the universal common ancestor of all cellular lineages.

Methane, arsenic, selenium and the origins of the DMSO reductase family.

Mononuclear molybdoenzymes of the dimethyl sulfoxide reductase (DMSOR) family catalyze a number of reactions essential to the carbon, nitrogen, sulfur, arsenic, and selenium biogeochemical cycles. These enzymes are also ancient, with many lineages likely predating the divergence of the last universal common ancestor into the Bacteria and Archaea domains. We have constructed rooted phylogenies for over 1,550 representatives of the DMSOR family using maximum likelihood methods to investigate the evolution of the arsenic biogeochemical cycle.

Arsenolipids in Cultured Strain ML and Their Occurrence in Biota and Sediment from Mono Lake, California.

Primary production in Mono Lake, a hypersaline soda lake rich in dissolved inorganic arsenic, is dominated by strain ML. We set out to determine if this photoautotrophic picoplankter could metabolize inorganic arsenic and in doing so form unusual arsenolipids (e.g.

Functional mononuclear molybdenum enzymes: challenges and triumphs in molecular cloning, expression, and isolation.

Mononuclear molybdenum enzymes catalyze a variety of reactions that are essential in the cycling of nitrogen, carbon, arsenic, and sulfur. For decades, the structure and function of these crucial enzymes have been investigated to develop a fundamental knowledge for this vast family of enzymes and the chemistries they carry out. Therefore, obtaining abundant quantities of active enzyme is necessary for exploring this family's biochemical capability.

Arsenic and the gastrointestinal tract microbiome.

Arsenic is a toxin, ranking first on the Agency for Toxic Substances and Disease Registry and the Environmental Protection Agency Priority List of Hazardous Substances. Chronic exposure increases the risk of a broad range of human illnesses, most notably cancer; however, there is significant variability in arsenic-induced disease among exposed individuals. Human genetics is a known component, but it alone cannot account for the large inter-individual variability in the presentation of arsenicosis symptoms.

Determining conventional and unconventional oil and gas well brines in natural samples III: mass ratio analyses using both anions and cations.

Identifying the types of contamination and their sources in surface and groundwater is fundamental for effective protection of private and public source waters. Here we employed mass ratio analyses of a variety of anion and cation pairs to characterize flowback, produced water, and mine drainage. These endmembers were used to evaluate the source contributions of natural surface and ground water samples.

Determining conventional and unconventional oil and gas well brines in natural sample II: Cation analyses with ICP-MS and ICP-OES.

Flowback and produced water generated by the hydraulic fracturing of unconventional oil and gas plays contain a suite of cations (e.g., metals) typically in a high salt (e.

Determining conventional and unconventional oil and gas well brines in natural samples I: Anion analysis with ion chromatography.

Unconventional natural gas extraction by hydraulic fracturing requires millions of gallons of water and generates flowback water, produced water and recycled fluids of varying chemical composition. Ion chromatography (IC) is a relatively low cost and efficient means to determine the anionic composition, however, the wide range in anionic content of these fluids poses a challenge to analytical methods developed for "natural" waters. We report here that the combination of UV and conductivity detectors increased detection sensitivity (e.

The center of olfactory bulb-seeded α-synucleinopathy is the limbic system and the ensuing pathology is higher in male than in female mice.

At early disease stages, Lewy body disorders are characterized by limbic vs. brainstem α-synucleinopathy, but most preclinical studies have focused solely on the nigrostriatal pathway. Furthermore, male gender and advanced age are two major risk factors for this family of conditions, but their influence on the topographical extents of α-synucleinopathy and the degree of cell loss are uncertain.

Respiratory Selenite Reductase from Bacillus selenitireducens Strain MLS10.

The putative respiratory selenite [Se(IV)] reductase (Srr) from MLS10 has been identified through a polyphasic approach involving genomics, proteomics, and enzymology. Nondenaturing gel assays were used to identify Srr in cell fractions, and the active band was shown to contain a single protein of 80 kDa. The protein was identified through liquid chromatography-tandem mass spectrometry (LC-MS/MS) as a homolog of the catalytic subunit of polysulfide reductase (PsrA).

Molecular cloning, expression and biochemical characterization of periplasmic nitrate reductase from Campylobacter jejuni.

Campylobacter jejuni, a human gastrointestinal pathogen, uses nitrate for growth under microaerophilic conditions using periplasmic nitrate reductase (Nap). The catalytic subunit, NapA, contains two prosthetic groups, an iron sulfur cluster and a molybdenum cofactor. Here we describe the cloning, expression, purification, and Michaelis-Menten kinetics (kcat of 5.

Autotrophic microbial arsenotrophy in arsenic-rich soda lakes.

A number of prokaryotes are capable of employing arsenic oxy-anions as either electron acceptors [arsenate; As(V)] or electron donors [arsenite; As(III)] to sustain arsenic-dependent growth ('arsenotrophy'). A subset of these microorganisms function as either chemoautotrophs or photoautotrophs, whereby they gain sufficient energy from their redox metabolism of arsenic to completely satisfy their carbon needs for growth by autotrophy, that is the fixation of inorganic carbon (e.g.

Arsenite as an Electron Donor for Anoxygenic Photosynthesis: Description of Three Strains of Ectothiorhodospira from Mono Lake, California and Big Soda Lake, Nevada.

Three novel strains of photosynthetic bacteria from the family Ectothiorhodospiraceae were isolated from soda lakes of the Great Basin Desert, USA by employing arsenite (As(III)) as the sole electron donor in the enrichment/isolation process. Strain PHS-1 was previously isolated from a hot spring in Mono Lake, while strain MLW-1 was obtained from Mono Lake sediment, and strain BSL-9 was isolated from Big Soda Lake. Strains PHS-1, MLW-1, and BSL-9 were all capable of As(III)-dependent growth via anoxygenic photosynthesis and contained homologs of arxA, but displayed different phenotypes.

Gaia and her microbiome.

The Gaia hypothesis, proposed 50 years ago, posits that the Earth's biosphere, atmosphere, hydrosphere and lithosphere interact as a cybernetic system, maintaining the long-term habitability of the planet. The resulting chemical composition of the atmosphere, oceans and crust is unique as compared to the other planets of our solar system, and due to the presence of life. Together these components comprise the biosphere, the life support system of the planet, with most of the essential processes carried out by microbes.

Transmission of α-synucleinopathy from olfactory structures deep into the temporal lobe.

Background: α-synucleinopathy emerges quite early in olfactory structures such as the olfactory bulb and anterior olfactory nucleus (OB/AON) in Parkinson's disease. This may contribute to smell impairments years before the commencement of motor symptoms. We tested whether α-synucleinopathy can spread from the OB/AON to regions of the limbic telencephalon that harbor connections with olfactory structures.

Arsenic induces structural and compositional colonic microbiome change and promotes host nitrogen and amino acid metabolism.

Chronic exposure to arsenic in drinking water causes cancer and non-cancer diseases. However, mechanisms for chronic arsenic-induced pathogenesis, especially in response to lower exposure levels, are unclear. In addition, the importance of health impacts from xeniobiotic-promoted microbiome changes is just being realized and effects of arsenic on the microbiome with relation to disease promotion are unknown.