A5021222310- Microbial Community Ecology and Physiology
- Methane Hydrates and Related Phenomena
- Genomics and Phylogenetic Studies
- Planetary Science and Exploration
- Hydrocarbon exploration and reservoir analysis
- Atmospheric and Environmental Gas Dynamics
- Geology and Paleoclimatology Research
- Soil Carbon and Nitrogen Dynamics
- Radioactive element chemistry and processing
- Space Science and Extraterrestrial Life
- Groundwater flow and contamination studies
- CO2 Sequestration and Geologic Interactions
- Drilling and Well Engineering
- Bacteriophages and microbial interactions
- Geological Studies and Exploration
- Groundwater and Isotope Geochemistry
- Astro and Planetary Science
- Metal Extraction and Bioleaching
- Lichen and fungal ecology
- Reservoir Engineering and Simulation Methods
- Geological Modeling and Analysis
- Space Exploration and Technology
- Radioactivity and Radon Measurements
- Microbial Fuel Cells and Bioremediation
- Building materials and conservation
New Mexico Institute of Mining and Technology
2015-2024
University of California, Berkeley
1984-1987
University of New Mexico
1983-1984
University of Saskatchewan
1984
A committee of the Mars Exploration Program Analysis Group (MEPAG) has reviewed and updated description Special Regions on as places where terrestrial organisms might replicate (per COSPAR Planetary Protection Policy). This review update was conducted by an international team (SR-SAG2) drawn from both biological science exploration communities, focused understanding when could occur. The study applied recently available data about martian environments organisms, building a previous analysis...
Significance Microorganisms are known to live in the deep subsurface, kilometers below photic zone, but community-wide metabolic networks and trophic structures (the organization of their energy nutritional hierarchy) remain poorly understood. We show that an active subsurface lithoautotrophic microbial ecosystem (SLiME) under oligotrophic condition exists. Taxonomically metabolically diverse microorganisms supported, with sulfur-driven autotrophic denitrifiers predominating community....
Ester-linked phospholipid fatty acid (PLFA) profiles of a Pseudomonas aureofaciens strain and an Arthrobacter protophormiae strain, each isolated from subsurface sediment, were quantified in starvation experiment silica sand porous medium under moist dry conditions. Washed cells added to microcosms maintained saturated conditions or subjected desiccation by slow drying over period 16 days final water potentials approximately - 7.5 MPa for the P. 15 A. protophormiae. In third treatment, along...
ABSTRACT A thermophilic bacterium that can use O 2 , NO 3 − Fe(III), and S 0 as terminal electron acceptors for growth was isolated from groundwater sampled at a 3.2-km depth in South African gold mine. This organism, designated SA-01, clustered most closely with members of the genus Thermus determined by 16S rRNA gene (rDNA) sequence analysis. The rDNA SA-01 >98% similar to strain NMX2 A.1, which previously other investigators thermal spring New Mexico. Strain A.1 also able reduce...
Plant communities of large portions the southwestern United States have changed from grassland to desert shrubland. Previous studies demonstrated that soil nutrient resources become spatially more heterogeneous and are redistributed into islands fertility with shift in vegetation. The research presented here addressed question whether temporally as well when undergoes desertification form Within adjacent creosotebush sites, profiles were described at three pits, samples collected for...
On November 5–8, 2019, the "Mars Extant Life: What's Next?" conference was convened in Carlsbad, New Mexico. The gathered a community of actively publishing experts disciplines related to habitability and astrobiology. Primary conclusions are as follows: A significant subset attendees concluded that there is realistic possibility Mars hosts indigenous microbial life. powerful theme permeated key search for martian extant life lies identifying exploring refugia ("oases"), where conditions...
Although starvation survival has been characterized for many bacteria, few subsurface bacteria have tested, and if any tested in natural porous media. We hypothesized that may be uniquely adapted long-term situ. further conditions (sediment type moisture content) would influence microbial survival. compared capabilities of surface strains Pseudomonas fluorescens a novel Arthrobacter sp. microcosms composed sediments. Bacteria were incubated up to 64 weeks under saturated unsaturated...
In this article, a new mechanism influencing the transport of microorganisms through unsaturated porous media is examined, and method for directly visualizing bacterial behavior within medium under controlled chemical flow conditions introduced. Resting cells hydrophilic relatively hydrophobic strains isolated from groundwater were used as model microorganisms. The degree hydrophobicity was determined by contact-angle measurements. Glass micromodels allowed direct observation on pore scale,...
A newly discovered form of biological ice nucleus associated with lichens is described. Ice nucleation spectra a variety from the southwestern United States were measured by drop-freezing method. Several epilithic lichen samples genera Rhizoplaca, Xanthoparmelia , and Xanthoria had nuclei active at temperatures as warm −2.3°C densities 2.3 × 10 6 to more than 1 8 g −1 −5°C (2 4 orders magnitude higher any plants infected nucleation-active bacteria). Most tested activity above −8°C. Lichen...
ABSTRACT A microbial community analysis using 16S rRNA gene sequencing was performed on borehole water and a granite rock core from Henderson Mine, >1,000-meter-deep molybdenum mine near Empire, CO. Chemical of at two separate depths (1,044 m 1,004 below the entrance) suggests that sharp chemical gradient exists, likely mixing distinct subsurface fluids, one metal rich relatively dilute; this has created unique niches for microorganisms. The analyzed filtered, oxic indicated an abundance...
Microbial communities within deep subsurface environments were analyzed by 16S rRNA gene cloning. Clone libraries from 27 borehole fluid, 7 mining-contaminated, and 5 rock samples compared. Borehole fluids derived fractures populated microbial with low diversity an average of 11 bacterial archaeal OTUs respectively. Low taxa richness was likely driven limited biogeochemical reactions available for growth not extreme parameters such as pH temperature. Novel Firmicutes discovered, commonly...
Comparative studies on community phylogenetics and phylogeography of microorganisms living in extreme environments are rare. Terrestrial subsurface habitats valuable for studying microbial biogeographical patterns due to their isolation the restricted dispersal mechanisms. Since taxonomic identity a microorganism does not always correspond well with its functional role particular community, use assignments or may give limited inference how functions affected by historical, geographical...
South Africa has numerous thermal springs that represent topographically driven meteoric water migrating along major fracture zones. The temperature (40-70°C) and pH (8-9) of the in Limpopo Province are very similar to those low salinity encountered African mines at depths ranging from 1.0 3.1 km. cation anion composition these deep with exception dissolved inorganic carbon O2, both which typically higher than water. situ biological relatedness such subsurface fluids feed them not previously...
A major fraction of Earth's prokaryotic biomass dwells in the deep subsurface, where cellular abundances per volume sample are lower, metabolism is slower, and generation times longer than those surface terrestrial marine environments. How these conditions impact biotic interactions evolutionary processes largely unknown. Here we employed single cell genomics to analyze cell-to-cell genome content variability signatures horizontal gene transfer (HGT) viral infections five cells Candidatus...
Summary Rock, air and service water samples were collected for microbial analyses from 3.2 kilometres depth in a working Au mine the Witwatersrand basin, South Africa. The ∼ metre‐wide mined zone was comprised of carbonaceous, quartz, sulphide, uraninite bearing layer, called Carbon Leader, sandwiched by quartzite conglomerate. community dominated mesophilic aerobic anaerobic, α‐, β‐ γ‐ Proteobacteria with total biomass concentration ∼10 4 cells ml −1 , whereas, that members Chlorobi...
To understand the conditions under which microorganisms exist in deep hydrocarbon reservoirs, sidewall cores were collected from a natural gas‐bearing formation, 2800 m below surface Taylorsville Basin, Virginia. Data chemical and microbial tracers controls indicate that interiors of some contained indigenous to rock formation. The cultured composed primarily saline‐tolerant, thermophilic fermenting, Fe(III)‐reducing, sulfate‐reducing bacteria (1 104 cells/g). physiological capabilities are...
Water residing within crustal fractures encountered during mining at depths greater than 500 meters in the Witwatersrand basin of South Africa represents a mixture paleo-meteoric water and 2.0–2.3 Ga hydrothermal fluid. The fluid is highly saline, contains abiogenic CH 4 hydrocarbon, occasionally N 2 , originally formed ∼ 250–300°C cooling isotopically exchanged O H with minerals accrued He other radiogenic gases. ranges age from 10 Ka to > 1.5 Ma, low salinity, falls along global meteoric...