A5077134322- Polar Research and Ecology
- Microbial Community Ecology and Physiology
- Cryospheric studies and observations
- Marine and coastal ecosystems
- Geology and Paleoclimatology Research
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- Spaceflight effects on biology
- Biocrusts and Microbial Ecology
- Protist diversity and phylogeny
- Space Science and Extraterrestrial Life
- Methane Hydrates and Related Phenomena
- Microbial Metabolism and Applications
- Corrosion Behavior and Inhibition
- Wastewater Treatment and Nitrogen Removal
- Biosensors and Analytical Detection
- Genomics and Phylogenetic Studies
- Algal biology and biofuel production
- Atmospheric and Environmental Gas Dynamics
- Bacterial biofilms and quorum sensing
- Innovation, Sustainability, Human-Machine Systems
- Bacteriophages and microbial interactions
- Soil and Water Nutrient Dynamics
- Career Development and Diversity
- Climate change and permafrost
Montana State University
2015-2025
National Center for Advancing Translational Sciences
2020
E Ink (South Korea)
2020
University of California Davis Medical Center
2020
Environmental and Water Resources Engineering
2008
University of Toledo
1995-1998
Despite the integral role of ice nucleators (IN) in atmospheric processes leading to precipitation, their sources and distributions have not been well established. We examined IN snowfall from mid- high-latitude locations found that most active were biological origin. Of larger than 0.2 micrometer at temperatures warmer -7 degrees C, 69 100% biological, a substantial fraction bacteria. Our results indicate biosphere is source highly suggest these particles may affect precipitation cycle...
Rationale Determining the chemical constituents of natural organic matter (NOM) by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICRMS) remains ultimate measure for probing its source material, evolution, and transport; however, lability fate (OM) in environment remain controversial. FTICRMS‐derived elemental compositions are presented this study to validate a new interpretative method determine extent NOM from various environments. Methods FTICRMS data collected over last...
Biological ice nucleators (IN) function as catalysts for freezing at relatively warm temperatures (warmer than -10 degrees C). We examined the concentration (per volume of liquid) and nature IN in precipitation collected from Montana Louisiana, Alps Pyrenees (France), Ross Island (Antarctica), Yukon (Canada). The temperature detectable ice-nucleating activity more half samples was > or = -5 C based on immersion testing. Digestion with lysozyme (i.e., to hydrolyze bacterial cell walls) led...
Subglacial Lake Vostok is located ~4 km beneath the surface of East Antarctic Ice Sheet and has been isolated from atmosphere for ≫15 million yr. Concerns environmental protection have prevented direct sampling lake water thus far. However, an ice core retrieved above in which bottom ,85 m represents that accreted (i.e., frozen) to sheet. We measured selected constituents within accretion predict geomicrobiological conditions waters lake. Bacterial density two‐ sevenfold higher than...
Bacterial strains isolated from Antarctic environments were used to assess the role of carotenoid pigments as cryo- and solar radiation protectants. Isolates subjected one hundred 12-hr freeze-thaw cycles exposed ambient simulated (300 Wm−2) with growth recovery evaluated after pre-set time intervals. Differences in survival observed between pigmented non-pigmented response different stresses based upon enumeration colony forming units. On average more resistant compared strains. Survival...
Metabolic activity and biogeochemical diversity within cryoconites from the Canada, Commonwealth, Howard, Hughes glaciers in McMurdo Dry Valleys revealed presence of a productive microbial refuge this polar desert ecosystem. Fluorescent situ hybridization showed high percentage Cytophaga ‐ Flavobacteria cells cryoconite sediments (87.2%), while β Proteobacterial dominated ice overlying sediment layer (54.2%). The biomass bacterial was also greater (4.82 μ gC ml −1 ) than that (0.18 related...
Dynamics of dissolved organic matter (DOM) in ecosystems are controlled by a suite interacting physical, chemical, and biological factors. Growing recognition the associations between microbial communities metabolism intrinsic DOM characteristics, highlight potential importance microbe-DOM relationships to modulate role fate DOM, yet these difficult isolate because they often operate across confounding environmental gradients. In laboratory incubation (44 days), we integrated bulk molecular...
Abstract There is very little information about the activity of microbial communities on surface glaciers, though there an increasing body evidence to show that they strongly influence biogeochemistry these habitats. We measured bacterial abundance and production in cryoconite holes Arctic, Antarctic Alpine glaciers order estimate role heterotrophic bacteria within carbon budget glacial ecosystems. Our results demonstrate active community with doubling times vary from a few hours hundreds...
Abstract Many challenges remain before we can fully understand the multifaceted role that natural organic matter (NOM) plays in soil and aquatic systems. These despite considerable progress has been made understanding NOM’s properties reactivity using latest analytical techniques. For nearly 4 decades, International Humic Substances Society (IHSS, which is a non-profit scientific society) distributed standard substances adhere to strict isolation protocols reference materials are collected...
Microplastics have littered the globe, with synthetic fibers being largest source of atmospheric microplastics. Many particles can act as ice nucleators, thereby affecting microphysical and radiative properties clouds and, hence, balance Earth. The present study focused on ice-nucleating ability from clothing textiles (CTs), which are commonly shed normal wear apparel items. Results immersion nucleation experiments showed that CTs were effective nucleators active −6 to −12 °C, similar common...
Glaciers are important constituents in the Earth's hydrological and carbon cycles, with predicted warming leading to increases glacial melt transport of nutrients adjacent downstream aquatic ecosystems. Microbial activity on surfaces has been linked biological darkening cryoconite particles, affecting albedo increased melt. This phenomenon, however, only demonstrated for alpine glaciers Greenland Ice Sheet, excluding Antarctica. In this study, we show via confocal laser scanning microscopy...
The role of dissolved organic matter (DOM) in the trophic dynamics aquatic systems is difficult to study. One approach focus on activity extracellular enzyme that heterotrophic bacteria use obtain nutrients from DOM. These data are easy acquire, but interpret, because we lack general models relate these activities two sides reaction: DOM pool and bacterial production. To address this gap, collected water samples Maumee River nine dates May 1996 through November 1996. was filtered placed...
Abstract. Englacial ice contains a significant reservoir of organic material (OM), preserving chronological record materials from Earth's past. Here, we investigate if OM composition surveys in core research can provide paleoecological information on the dynamic nature our Earth through time. Temporal trends early Holocene extending back to Last Glacial Maximum (LGM) West Antarctic Ice Sheet Divide (WD) were measured by fluorescence spectroscopy. Multivariate parallel factor (PARAFAC)...
We highlight the role of COSPAR and scientific community in defining updating framework planetary protection. Specifically, we focus on Mars "Special Regions," areas where strict protection measures have to be applied before a spacecraft can explore them, given existence environmental conditions that may conducive terrestrial microbial growth. outline history concept Special Regions inform recent developments regarding policy, namely, MEPAG SR-SAG2 review Academies ESF joint committee report...
Vast expanses of Earth's surface are covered by ice, with microorganisms in these systems affecting local and global biogeochemical cycles. We examined microbial assemblages from habitats fed glacial meltwater within the McMurdo Dry Valleys, Antarctica on west Greenland Ice Sheet (GrIS), evaluating potential physicochemical factors explaining trends community structure. Microbial present different Antarctic dry valley were dominated Sphingobacteria andFlavobacteria, while Gammaproteobacteria...
Studying biofilms in a microgravity environment currently relies on one of two scenarios, collecting planktonic aggregates rotating wall vessels or performing experiments the space International Space Station. While informative techniques, both have their limitations when studying surface-attached microbial communities. A simulated biofilm reactor (SMBR) was developed to study microgravity, coupled with integration microfabricated sensors for internal system monitoring. The establishment...