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Full-Text Articles in Life Sciences

Microbial Community Shifts Caused By Changes In The Primary Oxidant At A Drinking Water Treatment Plant, Connie Marie Moloney Dec 2014

Microbial Community Shifts Caused By Changes In The Primary Oxidant At A Drinking Water Treatment Plant, Connie Marie Moloney

Graduate Theses and Dissertations

Microbial communities resistant to common oxidants can cause concerns for water treatment plants (WTPs). If a bacterium is not fully oxidized during disinfection, these species can impede upon filtration processes or seed biofilms in the distribution system. In an effort to minimize disinfection by-products (DBP's) that result from the reaction of chlorine (Cl2) with natural organic matter, water treatment plants have the option to change their primary oxidant to chlorine dioxide (ClO2). The following study examines the change in microbial communities during the sedimentation process under differing oxidation regimes, specifically chlorine (Cl2) and ClO2 at the local water treatment plant …


Predation Thresholds In Marine Microbial Communities Applied To Environments With Low Prey Abundances, Bonnie Bailey Oct 2014

Predation Thresholds In Marine Microbial Communities Applied To Environments With Low Prey Abundances, Bonnie Bailey

OES Theses and Dissertations

Prokaryotes (Bacteria and Archaea) comprise the largest component of biomass in the world's oceans. Their abundances are controlled by resource availability, viral infections and protist grazing. Many pico- and nano-eukaryotic predators grow almost as quickly as their prey, and greatly increase in numbers as soon as their prey do, leading in tum to depletion in prokaryotes. It is still unclear however, as to what extent microbial predators are able to feed in low prey environments, most prominently in the largest biome on Earth, the deep sea (below l 000 m depth). It has been hypothesized that in low prey environments, …


A Mathematical Model Of Moisture Movement And Bacterial Growth In Two-Dimensional Porous Medium, Rachel Elizabeth Tewinkel May 2014

A Mathematical Model Of Moisture Movement And Bacterial Growth In Two-Dimensional Porous Medium, Rachel Elizabeth Tewinkel

Theses and Dissertations

Bacterial growth in sand is of concern in regard to the health of beaches. A mathematical model is presented that represents the movement of moisture and the growth of bacteria through a beach. Simulations were run by numerically solving Richards Equation using a Finite Volume Method in order to track moisture movement. A model of moisture-dependent bacterial growth was then implemented. These simulations show that elevated bacteria counts following rain events do not necessarily result from bacteria in the body of water, but can also be sourced from the sand. Additionally, four different moisture-dependent bacterial growth models are compared to …


Prokaryotic Diversity Of The Wastewater Outfalls, Reefs, And Inlets Of Broward County, Alexandra Mandina Campbell May 2014

Prokaryotic Diversity Of The Wastewater Outfalls, Reefs, And Inlets Of Broward County, Alexandra Mandina Campbell

HCNSO Student Theses and Dissertations

We applied culture-independent, next-generation sequencing (NGS) high throughput pyrosequencing, to characterize the microbial communities associated with near shore seawater in Broward County, FL. These waters flow over coral reef communities, which are part of the Florida reef tract, and are close to shore where bathers frequent. Through a close partnership with the NOAA FACE program, 38 total seawater samples were taken from 6 distinct locales -the Port Everglades and Hillsboro Inlets, Hollywood and Broward wastewater outfalls, and the associated reef waters-over the course of one year. Tagged 16S rRNA amplicons were used to generate longitudinal taxonomic profiles of marine bacteria …


Antimicrobial Resistance Of Channel Catfish Intestinal Microflora In The Arkansas And Ninnescah Rivers In Kansas, Jordan R. Hofmeier May 2014

Antimicrobial Resistance Of Channel Catfish Intestinal Microflora In The Arkansas And Ninnescah Rivers In Kansas, Jordan R. Hofmeier

Master's Theses

Antimicrobial compounds have been used by humans to counteract bacterial infections since 1910. Overuse of these compounds in clinical and agricultural applications has led to rapid evolution and global spread of antimicrobial resistance and rivers are the main receiving body for antimicrobials and resistant bacteria from urban effluents and agricultural runoff. When antimicrobial-resistant bacteria enter the aquatic environment, water acts as a physical pathway for their distribution. Subsequently, resistance genes become established in natural systems and pose threats to human health and ecological processes. Due to these potential threats, antimicrobial resistance in the aquatic environment should be closely monitored. To …


Dispersal Of Antibiotic-Resistant Bacteria Near Central Great Plains Feedlots, Jennifer R. Pfannenstiel-Klaus May 2014

Dispersal Of Antibiotic-Resistant Bacteria Near Central Great Plains Feedlots, Jennifer R. Pfannenstiel-Klaus

Master's Theses

Antibiotic resistance is a growing concern in medical and veterinary settings. Resistance can be worsened by misuse and overuse of antibiotics. Such situations can give rise to highly resistant organisms. Ciprofloxacin, a synthetic, broad-spectrum antibiotic used to treat gram-positive and gram-negative infections in humans, has similar chemical structure to enrofloxacin, which is used to treat animals. Cross-resistance might arise because of that similarity. This research describes the dispersal and prevalence of bacteria that exhibit ciprofloxacin resistance in relation to feedlots in the central Great Plains region. Six times in 2013, six feedlots were sampled for airborne bacterial communities at, upwind …


Remediation Of Tetracycline From Water Sources Using Vetiver Grass (Chrysopogon Zizanioides L. Nash) And Tetracycline-Tolerant Root-Associated Bacteria, Aparupa Sengupta Jan 2014

Remediation Of Tetracycline From Water Sources Using Vetiver Grass (Chrysopogon Zizanioides L. Nash) And Tetracycline-Tolerant Root-Associated Bacteria, Aparupa Sengupta

Dissertations, Master's Theses and Master's Reports - Open

Antibiotics are emerging contaminants worldwide. Due to insufficient policy regulations, public awareness, and the constant exposure of the environment to antibiotic sources has created a major environmental concern. Wastewater treatment plants (WWTP) are not equipped to filter-out these compounds before the discharge of the disinfected effluent into water sources (e.g., lakes and streams) and current available technologies are not equipped to remediate these compounds from environmental sources. Hence, the challenge remains to establish a biological system to remove these antibiotics from wastewater. An invitro hydroponic remediation system was developed using vetiver grass (Chrysopogon zizanioides L. Nash) to remediate tetracycline …


Structure-Function Analysis Of Zapc, An Ftsz-Ring Stabilizer, In Escherichia Coli Cytokinesis, Lukasz Tchorzewski Jan 2014

Structure-Function Analysis Of Zapc, An Ftsz-Ring Stabilizer, In Escherichia Coli Cytokinesis, Lukasz Tchorzewski

Dissertations and Theses

In Escherichia coli, cell division is defined by the polymerization and constriction of a cytokinetic ring (Z ring) formed by FtsZ, a tubulin-like GTPase, at midcell. Division also involves the formation of a multi-protein complex at midcell known as the divisome. Several divisome proteins promote the assembly/disassembly processes of FtsZ, thereby exercising spatiotemporal control over division. Among FtsZ regulatory proteins are the FtsZ ringassociated proteins (Zap), which either directly or indirectly stabilize the Z-ring by increasing lateral interactions amongst FtsZ protofilaments in the Z-ring. ZapA-D are recruited during early cytokinesis and have overlapping functions in stabilizing FtsZ at midcell, but …


Microbial Communities Colonizing Leaves During Early Decomposition Stages, Stephanie Harper Jan 2014

Microbial Communities Colonizing Leaves During Early Decomposition Stages, Stephanie Harper

Electronic Theses and Dissertations

Microbial communities associated with decaying leaves play an important role in the cycling of nutrients in stream ecosystems. In headwater streams that are deemed as heterotrophic, bacteria and fungi are main drivers of organic matter decomposition and thus partly responsible for facilitating the cycling of nutrients from leaves that fall into the stream. The main objective of this study was to compare microbial community composition between different leaf types during breakdown in stream ecosystems. To achieve this objective, I used a combination of field and laboratory trials. Field experiments were performed at the Luquillo Experimental Forest using Dacryodes excelsa and …