Environmental Microbiology and Microbial Ecology Commons^™

Isolating And Characterizing Lipid Degrading Microbes From Human Decomposition Soils, Brooke Amara Talley, Allison R. Mason, Jennifer Debruyn

Chancellor’s Honors Program Projects

No abstract provided.

Nitrite Cycling In The Primary Nitrite Maxima Of The Eastern Tropical North Pacific, Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, Karen L. Casciotti

OES Faculty Publications

The primary nitrite maximum (PNM) is a ubiquitous feature of the upper ocean, where nitrite accumulates in a sharp peak at the base of the euphotic zone. This feature is situated where many chemical and hydrographic properties have strong gradients and the activities of several microbial processes overlap. Near the PNM, four major microbial processes are active in nitrite cycling: ammonia oxidation, nitrite oxidation, nitrate reduction and nitrite uptake. The first two processes are mediated by the nitrifying archaeal/bacterial community, while the second two processes are primarily conducted by phytoplankton. The overlapping spatial habitats and substrate requirements for these microbes …

Fine-Scale Genetic Structure In Rhizosphere Microbial Communities Associated With Chamaecrista Fasciculata (Fabaceae), Mahboubeh Hosseinalizadeh Nobarinezhad, Lisa E. Wallace

Biological Sciences Faculty Publications

Soil microbiota of the rhizosphere are an important extension of the plant phenotype because they impact the health and fitness of host plants. The composition of these communities is expected to differ among host plants due to influence by host genotype. Given that many plant populations exhibit fine-scale genetic structure (SGS), associated microbial communities may also exhibit SGS. In this study, we tested this hypothesis using Chamaecrista fasciculata, a legume species that has previously been determined to have significant SGS. We collected genetic data from prokaryotic and fungal rhizosphere communities in association with 70 plants in an area of …

Effects Of Continuous In Situ Low-Dose Ionizing Radiation On Microorganisms, Molly E. Wintenberg

All Dissertations

Precise detection and monitoring of nuclear fuel cycle, enrichment, and weapon development activities are critical for supporting warfighter preparation in chemical, biological, radiological, nuclear, and explosives (CBRNE) operations, clandestine activities, and nuclear compliance. A biological sensing system could serve as an alternative to traditional detection methods by using organic material naturally present in the environment to discreetly detect residual trace nuclear material. Microorganisms provide an optimal platform for an alternative sensing system; however, their response to low levels of ionizing radiation is poorly characterized. Combining the power of next-generation sequencing and transcriptomic analysis, this dissertation takes an approach to obtain …

Microbiological Contamination Associated With The Proximity Of A Refuse Dumpsite To A River Situated In Okada, Edo State, Nigeria, Ebere J. Okafor-Elenwo, Odaro S. Imade, Osazee E. Izevbuwa

Journal of Bioresource Management

This study was performed to evaluate the potential contamination of the Okponha river situated near a dumpsite in Okada, Edo State, Nigeria. Water samples were collected and analyzed for bacteriological and parasitological quality using standard procedures. Isolation and enumeration of bacterial colonies were performed by pour plate technique and the isolated bacteria were identified by standard phenotypic tests. Helminths and protozoa were screened by the direct smear technique. The values of HPC (3.79 ± 0.12 log₁₀ CFU/ml) and TCC (2.20 ± 0.14 log₁₀ CFU/ml) obtained from the river water samples exceeded WHO and NAFDAC recommended limits (≤ 2 …

Atp Luminescence Assay As A Bioburden Estimator Of Biomass Accumulation In Caves, Janez Mulec, Andreea Oarga-Mulec

International Journal of Speleology

A commercially available adenosine triphosphate (ATP) detection system (Hygiena, USA), supported by cultivable microbial indicators, was used to estimate bioburden in different habitats in and outside show caves: air, water and solid surfaces. A strong positive correlation between ATP concentration expressed as Relative Light Units (RLU) and Colony-Forming-Units (CFU) was observed for swab samples from cave surfaces. In terms of ATP units, surfaces in a single cave system (Postojna Cave) varied considerably (240-1,258,800 RLU/ 20 cm²) and commonly exceeded the bioburden level of analogues on the surface (0-114,390 RLU/ 20 cm²). Cave sub-habitats were colonized by …

A Study On The Dissolution Of Autunite Minerals By Facultative Bacteria In Bicarbonate Media, Sandra C. Herrera Landaez

FIU Electronic Theses and Dissertations

Uranium (U) is a key contaminant at the Hanford site. The formation of uranyl-phosphate bearing minerals such as autunite as a result of tripoliphosphate injections has been used as a U immobilization strategy. Bacteria are known as key factors governing the fate and transport of soil contaminants. This research evaluated the interaction of facultative bacteria Shewanella Oneidensis MR-1 with autunite mineral in bicarbonate-amended media solutions. The concentration of several elements such as U, calcium (Ca) and phosphorous (P) released as a result of autunite mineral biodissolution were determined as a function of time; changes in cell density and protein assay …

Examining Egg Surface Morphology And Microbial Content Of Sceloporus Virgatus Eggshells, Linnaea Arnett, Stacey Weiss Dr., Mark Martin Dr.

Summer Research

Eggs laid by the Sceloporus virgatus lizard are exposed to a variety of potentially protective microorganisms when passed through the cloaca, the opening at the end of both the reproductive and digestive tracts. Past data have indicated that eggs dissected out of the female before passing through the cloaca often have decreased hatching success, potentially due to the lack of protective bacteria on the dissected eggshell surface. This study examined the microorganisms found on both laid and dissected eggs at 0 weeks of incubation, as well as microbial and fungal content on the eggshells after 3 weeks of incubation in …

Bacterial Community Structure Of Contrasting Soils Underlying Bornean Rain Forests: Inferences From Microarray And Next-Generation Sequencing Methods, Sabrina E. Russo, Ryan Legge, Karrie A. Weber, Eoin L. Brodie, Katherine C. Goldfarb, Andrew K. Benson, Sylvester Tan

School of Biological Sciences: Faculty Publications

Soil microbial diversity is vast, and we lack even basic understanding of how this diversity is distributed ecologically. Using pyrosequencing and microarray methods, we quantified the structure of bacterial communities in two contrasting soils underlying Bornean rain forest (clay and sandy loam) that differ markedly in soil properties, aboveground tree flora, and leaf litter decomposition rates. We found significant soil-related taxonomic and phylogenetic differences between communities that, due to their proximity, are independent of climate. Bacterial communities showed distinct compositional and taxon-abundance distributions that were significantly correlated with the structure of the overlying tree community. Richness of bacteria was greater …

Diversity Of Estrogen Degrading Microorganisms In Las Vegas Wash And Lake Mead, Nevada, Usa, Susanna Blunt, Jim Bruckner, Jenny C. Fisher, Duane P. Moser

Lake Mead Science Symposium

Endocrine disrupting chemicals (EDCs) are a subject of intense research as more studies reveal their persistence in the environment and detrimental effects on wildlife. Steroid hormones, including the natural and synthetic estrogens estrone (E1), 17-beta-estradiol (E2) and 17- alpha-ethinyl estradiol (EE2), are among the most bioactive and have been detected at low concentrations in waterways downstream from wastewater treatment plants. Las Vegas Wash, a stream flowing into Lake Mead and fed primarily by treated wastewater, provides a unique experimental system in which to study the role microorganisms play in the fate and dispersal of these compounds in surface waters.

Heavy Metal Toxicity In Bioremediation: Microbial Cultures And Microscopy, Jason B. Goodbody

Theses and Dissertations

This research employed a variety of microscopy and spread plating techniques to observe the effects of heavy metal treatments on a toluene-selected bacterial population. Microbial colonies were cultured on spread plates and the resulting numbers were compared to respiration data. The mechanisms of reproduction were demonstrated to be more sensitive to metal treatments than were the mechanisms of respiration. Phase contrast, Gram stain, fluorescent microscopy, were used to compare and document a wide variety of bacteria resulting from different metal treatments as well as from environmental changes within the source bioreactor. The removal of sensitive bacteria and the selection of …

Phylogenetic Diversity Of The Bacterial Community From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl

OES Faculty Publications

The phylogenetic diversity of small-subunit rRNA genes associated,vith the domain Bacteria was examined (by using previously defined operational taxonomic units [C. L. Moyer, F. C. Dobbs, and D. M. Karl, Appl. Environ. Microbiol. 60:871-879, 1994]; those for Pele's Vents Bacteria are hereafter abbreviated PVB OTUs) with samples from a microbial mat at an active, deep-sea hydrothermal vent system. A cluster of phylogenetically related PVB OTUs (OTUs 2, 3, 6, and 8) was closely affiliated with Thiovulum sp. contained within the epsilon subclass of the class Proteobacteria and accounted for 60.5% of the small-subunit rRNA bacterial clone library from Pele's Vents. …

Sunlight Induced Movement Of Planktonic Organisms And Their Relationships To Water Movements, John Calkins, Ed Colley, Jay Wallingford, Carol Hulsey, Kathy Lohr, Marc Bolling

KWRRI Research Reports

Previous studies have shown the planktonic organisms of various natural water bodies to be quite sensitive to the levels of solar ultraviolet radiation incident at the water surface in summer. It has been assumed that the majority of the phytoplankton are simply carried about in the mass of the water which they inhabit with little control of their position or sunlight exposure. Photosynthetic microorganisms must strike a delicate balance with regard to solar radiation; they must obtain enough visible light for adequate photosynthesis while avoiding an excessive exposure to the injurious solar UV-B radiation.

It is proposed that the circulation …

Distribution Of Microorganisms In The Soil As Affected By Plowing And Subtilling Crop Residues, Roy C. Dawson, Virginia T. Dawson, T. M. Mccalla

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

The purpose of this investigation was primarily to determine what effects rate and method of application of residues have on the distribution of microorganisms within the plow-depth layer of soil.