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Articles 1 - 19 of 19
Full-Text Articles in Microbiology
The Expanding Marine Built Environment And Biofilm Formation Processes, Rachel Mugge
The Expanding Marine Built Environment And Biofilm Formation Processes, Rachel Mugge
Dissertations
The marine built environment (i.e., places or things made or modified by humans) in the northern Gulf of Mexico is rapidly expanding and includes over 2,000 known historic shipwrecks, nearly 4,100 artificial reefs, and other built structures for natural resource extraction, marine aquaculture, renewable energy generation, munitions dumping areas, and commercial and recreational activities. While these structures have the potential to develop into artificial reefs, acting as biodiversity hotspots that provide food and shelter and facilitate organism transport, it is unclear how they affect biodiversity and ecosystem function in the marine environment. The success of artificial reefs to become ecosystems …
Consequences Of Biofilm Architecture On Vibrio Cholerae Ecology And Life History, Benjamin Ray Wucher
Consequences Of Biofilm Architecture On Vibrio Cholerae Ecology And Life History, Benjamin Ray Wucher
Dartmouth College Ph.D Dissertations
The diversity of microbes and the environments they inhabit are staggering. In many of these environments, bacteria have evolved to form sessile surface attached communities called biofilms. These biofilms have wide reaching impacts from importance in global carbon cycling, to persistent catheter infections, to biofouling and wastewater treatment. While many species of microbes form biofilms to survive in their environment, the architectures of these structures vary widely between organisms. Even though a great deal of work has been done to understand bacterial communities and their functions, little work has examined how the spatial aspects of biofilm architecture can affect the …
Biomass Estimation Of Marine Biofilms On Plastic Surfaces, Kian Banihashemi, Fernando Javier Gil
Biomass Estimation Of Marine Biofilms On Plastic Surfaces, Kian Banihashemi, Fernando Javier Gil
Biological Sciences
Plastics have become a major source of marine pollution, which threatens food safety and quality, human health, and marine ecosystems. Due to the drastic negative effects of plastics in a marine environment, alternative biodegradable plastics are being generated that are more eco-friendly and have less environmental impact. Though some of these plastics are known to biodegrade, the process of degradation for bioplastics has not been heavily studied in a marine environment. This pilot project sought to both quantify the process of biodegradation and compare across different methods for effectiveness of biomass estimation, which serves as an indicator of biodegradation. Plastics …
Evidence For Metabolic Diversity In Meso-Neoproterozoic Stromatolites (Vazante Group, Brazil), Flavia Callefo, Fresia Ricardi-Branco, Mirian Mírian Liza Alves Forancelli Pacheco, Alexandre Ribeiro Cardoso, Nora Noffke, Verônica De Carvalho Teixeira, Itamar Tomio Neckel, Lara Maldanis, Emma Bullock, Dina Bower, Adalene Moreira Silva, Dario Ferreira Sanchez, Fabio Rodrigues, Douglas Galante
Evidence For Metabolic Diversity In Meso-Neoproterozoic Stromatolites (Vazante Group, Brazil), Flavia Callefo, Fresia Ricardi-Branco, Mirian Mírian Liza Alves Forancelli Pacheco, Alexandre Ribeiro Cardoso, Nora Noffke, Verônica De Carvalho Teixeira, Itamar Tomio Neckel, Lara Maldanis, Emma Bullock, Dina Bower, Adalene Moreira Silva, Dario Ferreira Sanchez, Fabio Rodrigues, Douglas Galante
OES Faculty Publications
Deciphering the evolution of ecological interactions among the metabolic types during the early diversification of life on Earth is crucial for our understanding of the ancient biosphere. The stromatolites from the genus Conophyton cylindricus represent a datum for the Proterozoic (Meso to Neoproterozoic) on Earth. Their typical conical shape has been considered a result of a competition between microorganisms for space, light and nutrients. Well-preserved records of this genus from the "Paleontological Site of Cabeludo ", Vazante Group, São Francisco Craton (Southern Brazil) present in situ fossilized biofilms, containing preserved carbonaceous matter. Petrographic and geochemical analyses revealed an alternation between …
How Historic Shipwrecks Influence Dispersal Of Deep-Sea Microbiomes, Rachel Moseley
How Historic Shipwrecks Influence Dispersal Of Deep-Sea Microbiomes, Rachel Moseley
Master's Theses
This thesis investigates how historic shipwrecks potentially shape dispersal of deep-sea microbiomes. Processes impacting dispersal of microbiomes around artificial structures in the ocean and how they connect to other deep-sea habitats is unknown. Dispersal processes are explained for some macroorganisms by theories in ecology, specifically the Theory of Island Biogeography and the Wooden Stepping Stone hypothesis. These have not been investigated for microorganisms, and thus this work will probe if they are applicable to microbial biogeography in this habitat. Experiments were conducted to establish new “island-like” features in near proximity (25-125 m) to wooden-hulled historic shipwrecks in the northern Gulf …
Approaches To Studying Bacterial Biofilms In The Bioeconomy With Nanofabrication Techniques And Engineered Platforms., Michelle Caroline Halsted
Approaches To Studying Bacterial Biofilms In The Bioeconomy With Nanofabrication Techniques And Engineered Platforms., Michelle Caroline Halsted
Doctoral Dissertations
Studies that estimate more than 90% of bacteria subsist in a biofilm state to survive environmental stressors. These biofilms persist on man-made and natural surfaces, and examples of the rich biofilm diversity extends from the roots of bioenergy crops to electroactive biofilms in bioelectrochemical reactors. Efforts to optimize microbial systems in the bioeconomy will benefit from an improved fundamental understanding of bacterial biofilms. An understanding of these microbial systems shows promise to increase crop yields with precision agriculture (e.g. biosynthetic fertilizer, microbial pesticides, and soil remediation) and increase commodity production yields in bioreactors. Yet conventional laboratory methods investigate these micron-scale …
Elucidating The Molecular Pathways Involved In The Fitness And Water Stress Response Of Pseudomonas Synxantha 2-79 In The Plant Rhizosphere, Clint Henry D. Pablo
Elucidating The Molecular Pathways Involved In The Fitness And Water Stress Response Of Pseudomonas Synxantha 2-79 In The Plant Rhizosphere, Clint Henry D. Pablo
Master's Theses
Pseudomonas synxantha 2-79 is a biocontrol agent that represents beneficial indigenous rhizobacteria that are broadly distributed in the Pacific Northwest, USA and flourish in the rhizosphere of commercially grown wheat under surprisingly arid conditions. The molecular adaptation of 2-79-like bacteria to plants growing in dry soils is poorly understood. We hypothesized that the ability of 2-79 to colonize and persist in the rhizosphere of water-stressed plants is underpinned by the formation of hydrating biofilms and the utilization of root exudates that contain plant-derived osmoprotectants called quaternary ammonium compounds (QACs). We tested this hypothesis by identifying waters stress response pathways in …
Cyanobacterial And Algal Abundance And Biomass In Cave Biofilms And Relation To Environmental And Biofilm Parameters, Slađana Popović, Nataša Nikolić, Jelena Jovanović, Dragana Predojević, Ivana Trbojević, Ljiljana Manić, Gordana Subakov Simić
Cyanobacterial And Algal Abundance And Biomass In Cave Biofilms And Relation To Environmental And Biofilm Parameters, Slađana Popović, Nataša Nikolić, Jelena Jovanović, Dragana Predojević, Ivana Trbojević, Ljiljana Manić, Gordana Subakov Simić
International Journal of Speleology
Due to life in extreme environments, cyanobacteria and algae from cave biofilms that form at the entrances or deep inside the cave around artificial lights are of increasing interest to many scientists. It is well-known that many phototrophic microorganisms are first to colonize exposed substrata and produce the organic matter on which other biofilm constituents relly. Many studies dealing with phototrophic microorganisms from biofilms focus on the diversity and community composition of cyanobacteria and algae, while quantitative assessments are rarely implemented. Biofilm sampling was conducted in Degurić and Vernjikica Cave located in Western and Eastern Serbia, respectively. Ecological parameters (temperature, …
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 …
Sulfur Cave (Romania), An Extreme Environment With Microbial Mats In A Co2-H2S/O2 Gas Chemocline Dominated By Mycobacteria, Serban M. Sarbu, Joost W. Aerts, Jean-François Flot, Rob J.M. Van Spanning, Calin Baciu, Artur Ionescu, Boglárka M. Kis, Reka Incze, Sándor Sikó-Barabási, Zoltan Para, Botond Hegyeli, Nicu-Viorel Atudorei, Casey Barr, Kenneth Nealson, Ferenc L. Forray, Cristian Lascu, Emily J. Fleming, Wilbert Bitter, Radu Popa
Sulfur Cave (Romania), An Extreme Environment With Microbial Mats In A Co2-H2S/O2 Gas Chemocline Dominated By Mycobacteria, Serban M. Sarbu, Joost W. Aerts, Jean-François Flot, Rob J.M. Van Spanning, Calin Baciu, Artur Ionescu, Boglárka M. Kis, Reka Incze, Sándor Sikó-Barabási, Zoltan Para, Botond Hegyeli, Nicu-Viorel Atudorei, Casey Barr, Kenneth Nealson, Ferenc L. Forray, Cristian Lascu, Emily J. Fleming, Wilbert Bitter, Radu Popa
International Journal of Speleology
Sulfur Cave (Puturosu Mountain, Romania) is an extreme environment, unique for displaying life in a gas chemocline. The lower part of the cave is filled with CO2, CH4, and H2S of mofettic origin, while the upper part contains air that floats above the heavier volcanic gasses. S° and H2SO4 (from sulfur-oxidation) cover the cave wall at and below the CO2-H2S:O2 gas/gas interface. On the cave wall, near the interface the pH is < 1 and unusual microbial biofilms occur on the rock’s surface. We provide context information on the geology, mineralogy, chemistry and biology to better understand this unique environment. We have used X-ray diffraction, optical microscopy, scanning electron microscopy with EDAX capabilities, stable isotope analysis and 16S and 18S rDNA amplicon sequencing. The most common taxa in the microbial biofilms are Mycobacteria, Acidithiobacillus and Ferroplasmaceae. Liquid water in this system originates solely from condensation of water …
Relationships Between Factors Influencing Biofilm Formation And Pathogen Retention In Complex Rhizosphere Microbial Communities, Aaron Coristine
Relationships Between Factors Influencing Biofilm Formation And Pathogen Retention In Complex Rhizosphere Microbial Communities, Aaron Coristine
Theses and Dissertations (Comprehensive)
Riparian wetlands are unique habitats facilitating all forms of life. The riverbanks of these environments provide ideal conditions for bacteria, plants, and higher organisms. Of particular interest to this research was the variation in microbial community structure at high, intermediate and poor water quality impacted areas. Assessing the capabilities of plants to retain microbial pathogens was identified. Root systems and corresponding soil are ideal locations for bacterial deposition, resulting in attachment at these areas. Biofilm production in these regions is important for long-term establishment, leading to persistence and potential naturalization. Opportunistic pathogens originating from mammalian fecal matter are introduced into …
Flood Events Can Reduce Key Fatty Acid Content Of Early-Stage Benthic Algal Assemblages In An Urban Stream, Sarah Whorley, John Wehr
Flood Events Can Reduce Key Fatty Acid Content Of Early-Stage Benthic Algal Assemblages In An Urban Stream, Sarah Whorley, John Wehr
Articles & Book Chapters
Effects of urbanization on stream chemistry and biota have been widely examined. However, few studies quantify the effect of urban stream characteristics on the biochemical properties of basal food resources, such as benthic algae, which can affect aquatic consumers and food webs. A common feature of urban streams is the high frequency of short floods, which may disrupt aquatic communities and their biotic controls. These disturbances can create algal assemblages low in biomass and which remain in early successional stages. This study examined the effects of frequent flood events and macroinvertebrate grazing on biomass, elemental stoichiometry, and essential fatty acid …
Cyanobacteria, Algae And Microfungi Present In Biofilm From Božana Cave (Serbia), Slađana Popović, Gordana Subakov Simić, Miloš Stupar, Nikola Unković, Dragana Predojević, Jelena Jovanović, Milica Ljaljević Grbić
Cyanobacteria, Algae And Microfungi Present In Biofilm From Božana Cave (Serbia), Slađana Popović, Gordana Subakov Simić, Miloš Stupar, Nikola Unković, Dragana Predojević, Jelena Jovanović, Milica Ljaljević Grbić
International Journal of Speleology
Phototrophic microorganisms (cyanobacteria and algae) and microfungi, were identified from biofilm on the walls of the entrance of BožanaCavein west Serbia. Temperature, relative humidity and light intensity were measured, and chlorophyll a content determined. Light intensity differed from the entrance inwards. However, Chl a content was not proportional to light intensity, instead it was positively correlated to biofilm weight. Biofilm samples from two sites were also observed using a scanning electron microscope. Coccoid forms of cyanobacteria were abundant at the sampling site with the lowest light intensity, while members of the order Nostocales were predominant at the sampling site with …
Dielectric Barrier Discharge Atmospheric Cold Plasma For Inactivation Of Pseudomonas Aeruginosa Biofilms, Dana Ziuzina, Sonal Patil, Patrick Cullen, Daniela Boehm, Paula Bourke
Dielectric Barrier Discharge Atmospheric Cold Plasma For Inactivation Of Pseudomonas Aeruginosa Biofilms, Dana Ziuzina, Sonal Patil, Patrick Cullen, Daniela Boehm, Paula Bourke
Articles
In recent years, atmospheric cold plasma (ACP) has been widely investigated for potential application as an alternative decontamination technology in biomedical and healthcare sectors. In this study, the antimicrobial efficacy of ACP against Pseudomonas aeruginosa biofilms was investigated. The 48-h biofilms were treated inside sealed polypropylene containers with a high-voltage dielectric barrier discharge (DBD) ACP (80 kVRMS) and subsequently stored for 24 h at room temperature. Treatment for 60 s by either the direct or indirect mode of ACP exposure (inside or outside plasma discharge, respectively) reduced bacterial populations by an average of 5.4 log cycles from an initial 6.6 …
Effects Of Biodiesel Concentration On Microbial Deterioration Of Polyethylene In A Simulated Fuel Storage Tank, Juan Manuel Restrepo-Florez
Effects Of Biodiesel Concentration On Microbial Deterioration Of Polyethylene In A Simulated Fuel Storage Tank, Juan Manuel Restrepo-Florez
Electronic Thesis and Dissertation Repository
In this study a simulated fuel storage tank was used to investigate the effect of biodiesel concentration on biodegradation of polyethylene. This research is relevant in the field of fuel storage. The simulated storage system consisted of a number of identical conical flasks. Each flask was comprised of two layers, an upper one consisting of a fuel blend of diesel with biodiesel in concentrations ranging from 0 to 100% of biodiesel and the bottom layer containing an aqueous mineral media inoculated with a community obtained from a real fuel storage facility. Polyethylene slabs cut to a specific size were immersed …
Development And Characterization Of An In Vitro Four-Species Anaerobic Dental Biofilm Model, Fernando Andrade
Development And Characterization Of An In Vitro Four-Species Anaerobic Dental Biofilm Model, Fernando Andrade
Dissertations & Theses (Open Access)
Dental caries is the most common chronic disease worldwide. It is characterized by the demineralization of tooth enamel caused by acid produced by cariogenic dental bacteria growing on tooth surfaces, termed bacterial biofilms. Cariogenesis is a complex biological process that is influence by multiple factors and is not attributed to a sole causative agent. Instead, caries is associated with multispecies microbial biofilm communities composed of some bacterial species that directly influence the development of a caries lesion and other species that are seemingly benign but must contribute to the community in an uncharacterized way. Clinical analysis of dental caries and …
Chemoorganotrophic Bacteria Isolated From Biodeteriorated Surfaces In Cave And Catacombs, Filomena De Leo, Agnese Iero, Gabrielle Zammit, Clara E. Urzi
Chemoorganotrophic Bacteria Isolated From Biodeteriorated Surfaces In Cave And Catacombs, Filomena De Leo, Agnese Iero, Gabrielle Zammit, Clara E. Urzi
International Journal of Speleology
The main objective of this work was the comparative analysis of a large number of bacterial strains isolated from biodeteriorated surfaces in three different sites, namely the catacombs of St. Callistus in Rome, Italy, the catacombs dedicated to St. Agatha in Rabat, Malta and the Cave of Bats in Zuheros, Spain. Our results showed that even considering only culturable chemoorganotrophic bacteria the variability is very high, reflecting the great variety of microhabitats present. Hence any strategies to prevent, control or eliminate the biofilm-embedded microbiota from an archeological surface should take into account a number of considerations as stipulated in our …
Biogeochemical Behavior Of Dissolved Arsenic And Uranium Concentrations In Public Water Supply Wells, Kevin J. Mcvey
Biogeochemical Behavior Of Dissolved Arsenic And Uranium Concentrations In Public Water Supply Wells, Kevin J. Mcvey
School of Natural Resources: Dissertations, Theses, and Student Research
Public water supply (PWS) wells currently contain dissolved uranium concentrations above the federally mandated maximum contaminant level (MCL) of 30 ppb (parts per billion) and dissolved arsenic concentrations above the 10 ppb MCL. Both uranium and arsenic are known to cause various forms of cancer in humans. Variations in total uranium concentrations in PWS wells in Nebraska indicate a relationship to the duration and rate of pumping in specific wells. Although total arsenic concentrations show some variability over time in specific wells, the relationship to pumping is not as clear. Previous studies show that iron and sulfur bacteria present in …
Propagation Of Adherent Bacteria On The Brittlestar Ophionereis Annulata (Le Conte) After Enrichment Of Seawater With Amino Acids, Michael A. Rice
Propagation Of Adherent Bacteria On The Brittlestar Ophionereis Annulata (Le Conte) After Enrichment Of Seawater With Amino Acids, Michael A. Rice
Michael A Rice
Epidermal surfaces of the ophiouroid Ophionereis annulata (Le Conte) were examined by scanning electron microscopy. Microvilli, which are characteristic of many transport epithelia, are present on the epidermal surfaces. Epidermal surfaces of freshly-collected brittlestars were compared with brittlestars that were maintained in the laboratory for 48 hours in fresh seawater and in seawater enriched with 20uM glycine. Very few bacteria were observed on the surface of the freshly-collected animals or on animals maintained in the laboratory in fresh seawater. The epidermal surfaces of animals maintained in seawater enriched with 20 uM glycine showed extensive mats of coccoid and bacilloid bacteria. …