Open Access. Powered by Scholars. Published by Universities.®
Environmental Microbiology and Microbial Ecology Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Biology (6)
- Bioinformatics (4)
- Plant Sciences (4)
- Agronomy and Crop Sciences (3)
- Engineering (3)
-
- Environmental Health (3)
- Pharmacology, Toxicology and Environmental Health (3)
- Biochemistry, Biophysics, and Structural Biology (2)
- Cell Biology (2)
- Cell and Developmental Biology (2)
- Computational Biology (2)
- Genetics and Genomics (2)
- Physical Sciences and Mathematics (2)
- Agricultural Science (1)
- Agriculture (1)
- Bacteriology (1)
- Biochemical and Biomolecular Engineering (1)
- Biodiversity (1)
- Biogeochemistry (1)
- Biotechnology (1)
- Chemical Engineering (1)
- Civil and Environmental Engineering (1)
- Computer Engineering (1)
- Data Science (1)
- Earth Sciences (1)
- Ecology and Evolutionary Biology (1)
- Environmental Engineering (1)
- Keyword
-
- Microbial community (2)
- Microbial ecology (2)
- Soil health (2)
- Agronomy (1)
- Ahr (1)
-
- Anabaena (1)
- Anaerobic (1)
- Archaea (1)
- Avian (1)
- Bioenegy crop (1)
- Biofilm (1)
- Carbon Monoxide Oxidation (1)
- Carbon fixation (1)
- Carbon monoxide (1)
- Chlorine (1)
- Cholera (1)
- Comparative (1)
- Conservation Practices (1)
- Cover crop (1)
- Cultivation (1)
- Diet (1)
- Dilution method (1)
- Diversity (1)
- EGFR (1)
- Elevation (1)
- Environmental factors (1)
- Eutrophication (1)
- Fresh water (1)
- Genomics (1)
- Geographic (1)
Articles 1 - 17 of 17
Full-Text Articles in Environmental Microbiology and Microbial Ecology
Evaluating Soil Health And Crop Yield In Louisiana Agricultural Systems: Impacts Of Best Management Practices And Prediction Models, Hector J. Mendoza Lagos
Evaluating Soil Health And Crop Yield In Louisiana Agricultural Systems: Impacts Of Best Management Practices And Prediction Models, Hector J. Mendoza Lagos
LSU Doctoral Dissertations
The adoption of conservation management practices is critical for improving soil health, enhancing nutrient use efficiency, and sustaining crop productivity in row crop systems in Louisiana. This study evaluated the role of conservation agronomic practices, soil biochemical indicators, and machine learning predictive models to improve soil nutrient dynamics, soil health indicators, microbial communities (MC), and crop productivity on a corn (Zea mays L.) research plot scale and in a commercial forty-hectare cotton (Gassypium hirsutum L.)-corn-soybean (Glycine max L.) rotation system in northeast Louisiana. The objectives of the study were to evaluate soil nutrient dynamics and MCs under …
Advancing Louisiana's Cropping Systems: Sustainable Bioenergy Production, Cover Crops, And Technology Integration, Pedro R. Carrillo
Advancing Louisiana's Cropping Systems: Sustainable Bioenergy Production, Cover Crops, And Technology Integration, Pedro R. Carrillo
LSU Doctoral Dissertations
The adoption of cover crops in Louisiana is lower than the national average, underscoring the need for region-specific research to address environmental challenges and demonstrate the short-term benefits of these practices within existing production systems. This research evaluated the integration of cover crops (CC) in energy cane (Saccharum spp.) and no-till cotton systems, focusing on their effects on soil health, nitrogen (N) management, and biomass production. Soil health indicators (SHIs), including enzymatic activities (β-glucosidase, β-glucosaminidase, and urease), protein N, inorganic N concentrations (nitrate and ammonium), soil organic matter (SOM), and microbial community composition assessed through ester-linked fatty acid …
The Ecological Responses To Hydroperiod Of Wetland Plant Species Determined By Manipulated Soil Surface Elevation (Marsh Organs), Brandon Wolff
The Ecological Responses To Hydroperiod Of Wetland Plant Species Determined By Manipulated Soil Surface Elevation (Marsh Organs), Brandon Wolff
LSU Master's Theses
As sea level rise, subsidence, and abandonment of natural deltaic processes due to a highly engineered Mississippi River continue to threaten Louisiana’s coastal wetlands, the need for a system-wide understanding of natural wetland land-building and preservation processes has never been greater. A key component of any wetland is the ever-changing water environment that periodically floods and dries the marsh platforms. The flooding depth, duration, and frequency, known as the hydroperiod, along with salinity and soil fertility are key determining factors of vegetation and marsh types at a particular location. Different types of vegetation will have different growth characteristics such as …
Evaluation Of Organic And Synthetic Herbicides Applications On Indicators Of Soil Health And Weed Suppression In A Conventional Cropping System In Louisiana, Caitlin Denux
LSU Doctoral Dissertations
Synthetic herbicides, with their varying modes of action, are well known for their efficiency in the suppression and control of weed species in U.S. agriculture. However, the consequences of using synthetic herbicides without attention to the surrounding environment can produce chemical run-off, changes in soil health and soil health conditions, and create herbicide-resistant weeds. These consequences have encouraged growers to find alternatives in their weed management programs. In this study, organic and synthetic herbicides were assessed on how well they performed in weed suppression surveys, and their potential effects on soil health indicators. Commonly used indicators include soil pH, β-glucosidase …
Ecology Of Viruses In Marine And Coastal Oxygen-Depleted Waters, Sophie Jurgensen
Ecology Of Viruses In Marine And Coastal Oxygen-Depleted Waters, Sophie Jurgensen
LSU Doctoral Dissertations
Deoxygenation of marine and coastal waters, both caused and exacerbated by a suite of abiotic and biotic factors, has been documented for more than sixty years. The incidence and severity of low-oxygen areas is predicted to expand globally in the coming decades. Despite their colloquial moniker “dead zones,” low-oxygen areas contain thriving and diverse microorganisms that have significant impacts on global biogeochemical cycles including contributing to positive feedback loops that further expand low-oxygen areas. While the diversity and activity of these microorganisms is beginning to be elucidated, the ecology of their viruses is particularly understudied. In this dissertation, I present …
Analysis Of Geographic Variability Of Fecal Microbiomes Of Fratercula Arctica And Cross-Comparison Of Fecal Microbiomes Of Different Avian Feeding Types, Eric Jose Ramon Martinez
Analysis Of Geographic Variability Of Fecal Microbiomes Of Fratercula Arctica And Cross-Comparison Of Fecal Microbiomes Of Different Avian Feeding Types, Eric Jose Ramon Martinez
LSU Master's Theses
Gastrointestinal (gut) microbiota have a multitude of effects on their host, from aiding in digestion, to facilitating nutrient uptake, detoxification, and interactions with the immune system. Multiple factors have been identified that influence the composition of vertebrate microbiomes; these include host genetics, environmental conditions, diet and age, sex, and geography. However, broad inferences about wild avian gut microbial diversity and function under natural conditions are limited. Most knowledge on avian microbiomes is derived from studies on domestic poultry. Information on non-model taxa may provide important contextual information about vertebrate host-microbiome interactions and aid in future management of vulnerable species. Here, …
Responses Of Wetland Soil Microbial Communities To Different Types Of Anthropogenic Stress, Grace Ann Cagle
Responses Of Wetland Soil Microbial Communities To Different Types Of Anthropogenic Stress, Grace Ann Cagle
LSU Doctoral Dissertations
Microorganisms are the major drivers of biogeochemical transformations of carbon and nitrogen in wetlands. These processes are crucial for ecological sustainability and are heavily impacted by human activities. How anthropogenic stress affects the microbial drivers of carbon storage and nutrient cycling in wetlands is not well understood. I investigated the response of wetland soil microbial communities to three different types of anthropogenic stress using DNA sequencing. First, I studied the effect of warming on microbial carbon processing in a peatland underlaid by permafrost by comparing the abundances of specific genes between sites subjected to five years of warming and controls. …
Evidence For Perchlorate-Coupled Molybdenum And Nickel Carbon Monoxide Dehydrogenase Co Oxidation And Characterization Of Novel Perchlorate-Reducing Haloarchaea, Marisa Russell Myers
Evidence For Perchlorate-Coupled Molybdenum And Nickel Carbon Monoxide Dehydrogenase Co Oxidation And Characterization Of Novel Perchlorate-Reducing Haloarchaea, Marisa Russell Myers
LSU Doctoral Dissertations
Carbon monoxide (CO) has been exploited as a microbial energy source for much of life’s evolutionary history. A phylogenetically diverse array of microorganisms can oxidize CO using two distinct CO dehydrogenases, molybdenum-dependent (Mo-CODH) and nickel-dependent (Ni-CODH). Aerobes and facultative organisms contain Mo-CODHs which allow them to utilize oxygen as an electron acceptor in addition to alternatives such as nitrate and sulfate. Obligate anaerobic organisms contain Ni-CODHs, which oxidize CO at elevated concentrations, but cannot utilize oxygen. In systems where organic matter deposits are limited or absent, atmospheric trace gases such as CO are thought to assist in supporting the growth …
Distribution, Diversity, And Biogeography Of Anaerobic Carbon Monoxide Uptake By Microbial Communities In Soils And Sediments, Amber N. Depoy
Distribution, Diversity, And Biogeography Of Anaerobic Carbon Monoxide Uptake By Microbial Communities In Soils And Sediments, Amber N. Depoy
LSU Master's Theses
Carbon monoxide (CO) is primarily known for being a toxic gas. However, CO is used by microorganisms as an electron or carbon source in a variety of respiratory processes. Different kinds of microorganisms utilize CO aerobically and anaerobically, using two distinct CO dehydrogenases (CODHs). Aerobes oxidize CO using a molybdenum-dependent dehydrogenase (Mo-CODH), while anaerobes utilize a nickel-dependent CO dehydrogenase (Ni-CODH). Studies of the biochemistry and microbiology of aerobic and anaerobic CO oxidation are extensive, but relatively little is known about the ecology of anaerobic CO oxidation. In an effort to test new hypotheses about the ecology of anaerobic CO oxidation, …
A Comparison Of Intertidal Metazoan Biodiversity Between Previously Oiled Sheared And Intact Marsh Margins And Between Multiple Salinity Zones In The Coastal Marshes Of Louisiana, Patrick M. Rayle
LSU Master's Theses
Marshes in Louisiana are under threat from numerous natural and anthropogenic sources. A consequence of these threats are sheared marsh margins, which result from the impact of storm surge on previously oiled, weakened marsh. These conditions occurred in Louisiana marshes after Hurricane Isaac in 2012 followed the Deepwater Horizon oil spill in 2010, particularly in the shorelines surrounding Bay Jimmy. The second and third chapters of this thesis focus on the differences in biodiversity between the sheared and intact marsh margins in impacted sites in Bay Jimmy. Metabarcoding methods were used to determine community composition of the sediment within marsh …
The Effects Of Radical Containing Combustion Derived Particulate Matter In Adult Mouse Respiratory System, Jeffrey Harding
The Effects Of Radical Containing Combustion Derived Particulate Matter In Adult Mouse Respiratory System, Jeffrey Harding
LSU Doctoral Dissertations
Epidemiological data associates high levels of combustion-derived particulate matter (PM) with deleterious respiratory outcomes, but the mechanism underlying those outcomes remains elusive. It has been acknowledged by the World Health Organization that PM exposure contributes to more than 4.2 million all-cause mortalities worldwide each year. Current literature demonstrates that PM exacerbates respiratory diseases, impairs lung function, results in chronic respiratory illnesses, and is associated with increased mortality. The proposed mechanisms revolve around oxidative stress and inflammation promoting pulmonary physiological remodeling. Our data demonstrate that environmentally persistent free radicals (EPFRs) stabilized on the surface of PM are capable of inducing oxidative …
Plankton Dynamics In An Urban, Subtropical Lake Prior To Lake Restoration, Jennifer C. Pulsifer
Plankton Dynamics In An Urban, Subtropical Lake Prior To Lake Restoration, Jennifer C. Pulsifer
LSU Master's Theses
This research assessed plankton dynamics in two urban, subtropical lakes (University Lake and City Park Lake) shortly before a proposed and approved lake restoration project. Plankton dynamics were determined in University Lake by the dilution method to attempt to quantify growth rates of phytoplankton and grazing rates of zooplankton. Landry and Hassett’s (1982) dilution method has been widely used in marine systems to estimate rates of growth and grazing. In many marine systems, nutrients must be added to prevent nutrient limitation. However, it is assumed, due to the hypereutrophic conditions, that nutrients would not be a limitation in University Lake. …
Metabolic Network Analysis Of Filamentous Cyanobacteria, Daniel Alexis Norena-Caro
Metabolic Network Analysis Of Filamentous Cyanobacteria, Daniel Alexis Norena-Caro
LSU Doctoral Dissertations
Cyanobacteria were the first organisms to use oxygenic photosynthesis, converting CO2 into useful organic chemicals. However, the chemical industry has historically relied on fossil raw materials to produce organic precursors, which has contributed to global warming. Thus, cyanobacteria have emerged as sustainable stakeholders for biotechnological production. The filamentous cyanobacterium Anabaena sp. UTEX 2576 can metabolize multiple sources of Nitrogen and was studied as a platform for biotechnological production of high-value chemicals (i.e., pigments, antioxidants, vitamins and secondary metabolites). From a Chemical engineering perspective, the biomass generation in this organism was thoroughly studied by interpreting the cell as a microbial …
Effect Of Biosurfactant And Biochar On Ecosystem Functions And Oil Remediation In Crude Oil Contaminated Wetland Soils, Zhuo Wei
LSU Doctoral Dissertations
Decontamination of oil spill from coastal wetland soils requires a delicate approach. Remediation strategies using biochar, biosurfactant, and nutrient additions have been proposed. However, there is little information on application of these with combination for treatment of crude oil-contaminated wetland soil. Therefore, incubation studies were carried out to investigate the impact of biochar and rhamnolipid (RL) biosurfactant along with nitrogen (N) application on petroleum hydrocarbon degradation in a Louisiana coastal saline marsh and their impacts on greenhouse gas (GHG) emission. Additionally, the toxicity of crude oil as well as remediation materials on coastal wetland ecosystem were assessed at three levels: …
Effect Of Environmental Factors And Residual Sanitizers On Survival And Attachment Of Indicator Organism And Human Pathogens On Fresh Produce, Vijay Singh Chhetri
Effect Of Environmental Factors And Residual Sanitizers On Survival And Attachment Of Indicator Organism And Human Pathogens On Fresh Produce, Vijay Singh Chhetri
LSU Doctoral Dissertations
A comprehensive understanding of the behavior of microbial contaminants on produce surfaces in agricultural farms and during post-harvest activities is essential for the development of produce safety risk management strategies. Our studies investigated the survival and the attachment of E. coli on watermelon surfaces in agricultural settings with different levels of vegetation, and the effect of residual sanitizers on the survival and the attachment of E. coli O157: H7 and L. monocytogenes on spinach leaves. The attachment strength (SR) of the E. coli cells on watermelon surfaces significantly increased (P<0.05) from 0.04 to 0.99 in the first 24 h, which was primarily due to the decrease in loosely attached population, given that the population of strongly attached cells was constant. The daily die-off rate of E. coli ranged from -0.12 …
High-Throughput Cultivation Of Bacterioplankton From The Gulf Of Mexico And Genomics Of The First Cultured Ld12 Representative, Michael Winslow Henson
High-Throughput Cultivation Of Bacterioplankton From The Gulf Of Mexico And Genomics Of The First Cultured Ld12 Representative, Michael Winslow Henson
LSU Doctoral Dissertations
Cultivation of microorganisms facilitates characterization of metabolism, interspecies dependencies, virus-host interactions, and other information necessary to resolve the functions and distribution of individual taxa. However, the metabolic and physiological capacities for the majority of microbes remains unresolved because of the lack of cultivated representatives for many groups limits our ability to test cultivation-independent observations. The Northern Gulf of Mexico offers a diversity of ecosystems under the continuous threat from natural and anthropogenic disturbances, yet little is known about its native bacterioplankton community. This dissertation sought to use high-throughput cultivation over three-years at six sites to isolate important coastal bacteria to …
Phenotypic And Transcriptomic Characterization Of Colonial Phase Variation In The Cholera Pathogen Reveals A Novel Smooth Biofilm-Defective Form, Bliss Nicole Lambert
Phenotypic And Transcriptomic Characterization Of Colonial Phase Variation In The Cholera Pathogen Reveals A Novel Smooth Biofilm-Defective Form, Bliss Nicole Lambert
LSU Doctoral Dissertations
Biofilm formation, through the production of Vibrio polysaccharide (VPS), greatly enhances the environmental fitness and pathogenic success of Vibrio cholerae. As a result of phase variation, V. cholerae can switch from a smooth form to rugose, whose cells produce excess VPS, resulting in highly structured biofilms and greater resistance to stress. To further characterize the reversible process of phase variation, we isolated three colonial lineages. Each lineage began with a smooth parent, N16961, and contained a rugose variant derived from the parent, N16961R, as well as a smooth revertant of the rugose, N16961SD. We found clear phenotypic and transcriptomic …