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2020

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Articles 121 - 150 of 459

Full-Text Articles in Microbiology

Characterization Of The Overexpression Of The Native H+-Pumping Pyrophosphatase In The Microalga Picochlorum Soloecismus, Kimberly T. Wright Jul 2020

Characterization Of The Overexpression Of The Native H+-Pumping Pyrophosphatase In The Microalga Picochlorum Soloecismus, Kimberly T. Wright

Biology ETDs

Microalgae are of interest for the creation of sustainable and cost competitive alternatives to petroleum-based fuels and chemicals. However, cultivation, extraction and processing of algal biomass requires improved yields to achieve economic feasibility. The advancement of microalgal biotechnology and various genetic engineering techniques allow the improvement of microalgae biomass for this purpose. Here, the characterization of the overexpression of the native vacuolar H+ pumping pyrophosphate (AVP1) in Picochlorum soloecismus was examined. AVP1 overexpression causes biomass increase in relevant plant crops. When overexpressed in this microalga it increases carbon storage in the form of starch in a closed laboratory photobioreactor. However, …

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Disruption Of Pyoverdine Synthesis In Pseudomonas Aeruginosa Through Periodic Disturbance Of Biofilm Structure, Rebecca J. Quinn Jul 2020

Disruption Of Pyoverdine Synthesis In Pseudomonas Aeruginosa Through Periodic Disturbance Of Biofilm Structure, Rebecca J. Quinn

All HCAS Student Capstones, Theses, and Dissertations

Infections due to bacteria were once easily treated using antibiotics. However, the effective shelf life of antibiotics is diminishing due to the rise and spread of antibiotic resistant bacteria. Accordingly, novel approaches to treating infections are required. Pseudomonas aeruginosa is a multi-drug resistant, biofilm forming opportunistic pathogen. A determinant of P. aeruginosa’s pathogenicity is pyoverdine, a siderophore that is used to sequester iron from the environment. After being produced by a bacterium, pyoverdine is secreted into the environment where it complexes with iron. The pyoverdine-iron complex is then returned to the bacteria through diffusion, where it drives the synthesis of …

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Evaluating Regional Agricultural Wastes As Substrates For The Mycelial Growth And Fruiting Body Yield Of Pleurotus Ostreatus, Daniel Rhiner Jul 2020

Evaluating Regional Agricultural Wastes As Substrates For The Mycelial Growth And Fruiting Body Yield Of Pleurotus Ostreatus, Daniel Rhiner

Master of Science in Integrative Biology Theses

Pleurotus ostreatus, commonly known as the oyster mushroom, is a widely cultivated culinary mushroom known for its ability to colonize a variety of lignocellulosic agricultural wastes. The ability of P. ostreatus to utilize these types of wastes as growth substrates suggests a potential for this organism to convert agricultural waste streams into locally productive and regenerative systems. Agriculture is a leading contributor to Georgia’s economy, but it also produces large amounts of plant-based agricultural wastes of little to no value. Repurposing these wastes into profitable culinary and medicinal mushrooms has become an increasingly appealing approach to mitigating these wastes. …

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Host-Dependent Differences In Replication Strategy Of The Sulfolobus Spindle-Shaped Virus Strain Ssv9 (A.K.A., Ssvk1): Infection Profiles In Hosts Of The Family Sulfolobaceae, Ruben M. Ceballos, Coyne Gareth Drummond, Carson Len Stacy, Elizabeth Padillo-Crespo, Kenneth M. Stedman Jul 2020

Host-Dependent Differences In Replication Strategy Of The Sulfolobus Spindle-Shaped Virus Strain Ssv9 (A.K.A., Ssvk1): Infection Profiles In Hosts Of The Family Sulfolobaceae, Ruben M. Ceballos, Coyne Gareth Drummond, Carson Len Stacy, Elizabeth Padillo-Crespo, Kenneth M. Stedman

Biology Faculty Publications and Presentations

The Sulfolobus Spindle-shaped Virus (SSV) system has become a model for studying thermophilic virus biology, including archaeal host-virus interactions and biogeography. Several factors make the SSV system amenable to studying archaeal genetic mechanisms (e.g., CRISPRs) as well as virus-host interactions in high temperature acidic environments. Previously, we reported that SSVs exhibited differential infectivity on allopatric vs. sympatric hosts. We also noticed a wide host range for virus strain SSV9 (a.k.a., SSVK1). For decades, SSVs have been described as “non-lytic” double-stranded DNA viruses that infect species of the genus Sulfolobus and release virions via budding rather than host lysis. In this …

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Microbiome Shifts Associated With The Introduction Of Wild Atlantic Horseshoe Crabs (Limulus Polyphemus) Into A Touch-Tank Exhibit, Ariel D. Friel, Sean A. Neiswenter, Cale O. Seymour, Lauren Rose Bali, Ginger Mcnamara, Fabian Leija, Jack Jewell, Brian P. Hedlund Jul 2020

Microbiome Shifts Associated With The Introduction Of Wild Atlantic Horseshoe Crabs (Limulus Polyphemus) Into A Touch-Tank Exhibit, Ariel D. Friel, Sean A. Neiswenter, Cale O. Seymour, Lauren Rose Bali, Ginger Mcnamara, Fabian Leija, Jack Jewell, Brian P. Hedlund

Life Sciences Faculty Research

The Atlantic horseshoe crab (Limulus polyphemus) is a common marine aquarium species and model organism for research. There is potential monetary and conservation value in developing a stable captive population of horseshoe crabs, however, one major impediment to achieving captivity is a lack of knowledge regarding captive diseases. We utilized 16S rRNA gene amplicon sequencing to track changes in the microbiomes of four body locations in three wild-caught (tracked over 14 months in captivity) and three tank-acclimated (>2 years in captivity) adult L. polyphemus in a touch tank at Shark Reef Aquarium at Mandalay Bay in Las Vegas, NV. …

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The Strengths, Weaknesses, Opportunities And Threats (Swot) Analysis Of The Severe Acute Respiratory Syndrome Coronavirus 2 Of Covid-19, Michael Oluyemi Babalola Ph.D Jul 2020

The Strengths, Weaknesses, Opportunities And Threats (Swot) Analysis Of The Severe Acute Respiratory Syndrome Coronavirus 2 Of Covid-19, Michael Oluyemi Babalola Ph.D

The University of Louisville Journal of Respiratory Infections

Introduction: SARS-CoV-2 is the etiologic agent of Coronavirus Disease 2019 (COVID-19), a highly contagious, emergent, acute, viral pneumonia that emanated sporadically in Wuhan, China, in December 2019. COVID-19 became a pandemic in February 2020, leading to 4,942,687 confirmed cases and over 321,987 deaths and grounding several economies around the world as of May 2020. Although global researchers, epidemiologists, virologists, and medical professionals rose steadily to contain the disease, in-depth knowledge of the virus and concerted efforts to combat it are still evolving. This research sought to elucidate the biological Strengths, Weaknesses, Opportunities, and Threats to SARS-CoV-2, with a view to …

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Plankton Dynamics In An Urban, Subtropical Lake Prior To Lake Restoration, Jennifer C. Pulsifer Jul 2020

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. …

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Improved Antimicrobial Properties Of Silver Nanoparticles With Methylene Blue, Ermek Belekov Jul 2020

Improved Antimicrobial Properties Of Silver Nanoparticles With Methylene Blue, Ermek Belekov

Masters Theses & Specialist Projects

Photosensitizing agents are the cornerstone of photodynamic therapy (PDT) that play essential role in deactivation process of multidrug resistant pathogens and tumor treatments. In this work we studied a photosensitizing agent made from mixture of silver nanoparticles (Ag NPs) and methylene blue (MB) which possess improved important characteristics like high photostability and high singlet oxygen yield. Ag NPs were synthesized by pulsed laser ablation technique in different aqueous solutions like Polyvinylpyrrolidone (PVP), citrate and Deionized (DI) water. The synthesized Ag NPs were characterized in depth using with transmission electron microscopy (TEM), UVVisible (UV-Vis), and photoluminescence (PL) spectra. Ag NPs were …

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Defective Early Innate Immune Response To Ectromelia Virus In The Draining Lymph Nodes Of Aged Mice Due To Impaired Dendritic Cell Accumulation., Colby Stotesbury, Eric B Wong, Lingjuan Tang, Brian Montoya, Cory J Knudson, Carolina R Melo-Silva, Luis J Sigal Jul 2020

Defective Early Innate Immune Response To Ectromelia Virus In The Draining Lymph Nodes Of Aged Mice Due To Impaired Dendritic Cell Accumulation., Colby Stotesbury, Eric B Wong, Lingjuan Tang, Brian Montoya, Cory J Knudson, Carolina R Melo-Silva, Luis J Sigal

Department of Microbiology and Immunology Faculty Papers

It is known that aging decreases natural resistance to viral diseases due to dysfunctional innate and adaptive immune responses, but the nature of these dysfunctions, particularly in regard to innate immunity, is not well understood. We have previously shown that C57BL/6J (B6) mice lose their natural resistance to footpad infection with ectromelia virus (ECTV) due to impaired maturation and recruitment of natural killer (NK) cells to the draining popliteal lymph node (dLN). More recently, we have also shown that in young B6 mice infected with ECTV, the recruitment of NK cells is dependent on a complex cascade whereby migratory dendritic …

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Epstein Barr Virus-Immortalizedｂlymphocytes Exacerbate Experimental Autoimmune Encephalomyelitis In Xenograft Mice, Pascal Polepole, Alison Bartenslager, Yutong Liu, Thomas M. Petro, Samodha C. Fernando, Luwen Zhang Jul 2020

Epstein Barr Virus-Immortalizedｂlymphocytes Exacerbate Experimental Autoimmune Encephalomyelitis In Xenograft Mice, Pascal Polepole, Alison Bartenslager, Yutong Liu, Thomas M. Petro, Samodha C. Fernando, Luwen Zhang

Nebraska Center for Virology: Faculty Publications

Multiple sclerosis (MS) is the most common autoimmune disorder affecting the central nervous system. Epstein-Barr virus (EBV) is a causative agent for infectious mononucleosis (IM) that is associated with MS pathogenesis. However, the exact mechanism by which EBV, specifically in IM, increases the risk for MS remains unknown. EBV immortalizes primary B lymphocytes in vitro and causes excessive B lymphocyte proliferation in IM in vivo. In asymptomatic carriers, EBV-infected B lymphocytes still proliferate to certain degrees, the process of which is tightly controlled by the host immune systems. Experimental autoimmune encephalomyelitis (EAE) mimics key features of MS in humans …

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Inactivation Of Hippo And Cjun-N-Terminal Kinase (Jnk) Signaling Mitigate Fus Mediated Neurodegeneration In-Vivo, Ankita Sarkar, Abijeet Singh Mehta, Prajakta Deshpande, Madhuri Kango-Singh, Udai Bhan Pandey, Amit Singh Jul 2020

Inactivation Of Hippo And Cjun-N-Terminal Kinase (Jnk) Signaling Mitigate Fus Mediated Neurodegeneration In-Vivo, Ankita Sarkar, Abijeet Singh Mehta, Prajakta Deshpande, Madhuri Kango-Singh, Udai Bhan Pandey, Amit Singh

Biology Faculty Publications

Amyotrophic Lateral Sclerosis (ALS), a late-onset neurodegenerative disorder characterized by the loss of motor neurons in the central nervous system, has no known cure to-date. Disease causing mutations in human Fused in Sarcoma (FUS) leads to aggressive and juvenile onset of ALS. FUS is a well-conserved protein across different species, which plays a crucial role in regulating different aspects of RNA metabolism. Targeted misexpression of FUS in Drosophila model recapitulates several interesting phenotypes relevant to ALS including cytoplasmic mislocalization, defects at the neuromuscular junction and motor dysfunction. We screened for the genetic modifiers of human FUS-mediated neurodegenerative phenotype using molecularly …

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Repression Of Tick Microrna-133 Induces Organic Anion Transporting Polypeptide Expression Critical For Anaplasma Phagocytophilumsurvival In The Vector And Transmission To The Vertebrate Host, Ellango Ramasamy, Vikas Taank, John F. Anderson, Hameeda Sultana, Girish Neelakanta Jul 2020

Repression Of Tick Microrna-133 Induces Organic Anion Transporting Polypeptide Expression Critical For Anaplasma Phagocytophilumsurvival In The Vector And Transmission To The Vertebrate Host, Ellango Ramasamy, Vikas Taank, John F. Anderson, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

The microRNAs (miRNAs) are important regulators of gene expression. In this study, we provide evidence for the first time to show that rickettsial pathogen Anaplasma phagocytophilum infection results in the down-regulation of tick microRNA-133 (miR-133), to induce Ixodes scapularis organic anion transporting polypeptide (isoatp4056) gene expression critical for this bacterial survival in the vector and for its transmission to the vertebrate host. Transfection studies with recombinant constructs containing transcriptional fusions confirmed binding of miR-133 to isoatp4056 mRNA. Treatment with miR-133 inhibitor resulted in increased bacterial burden and isoatp4056 expression in ticks and tick cells. In contrast, treatment with …

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Using Soil Geospatial Properties And Environments To Explore Microbial Diversity, Sharon Faye Smith Jul 2020

Using Soil Geospatial Properties And Environments To Explore Microbial Diversity, Sharon Faye Smith

Graduate Theses and Dissertations

Soil microorganisms help maintain nutrient cycling, control carbon sequestration, impact plant productivity, and influence several soil chemical and physical properties; yet, the processes that control the microbial composition of soil and how environmental changes may affect the composition and activity of these organisms at different scales remains a difficult and intriguing puzzle for soil scientists, ecologists, and modelers. Wetlands are endangered and important ecosystems that provide several services, which are directly linked to soil function. However, few wetland assessments consider the soil environment and microbial ecology. Linking soil microbial community composition and distribution patterns to soil physio-chemical properties would provide …

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Optimisation Of Biomass And Lipid Production Of A Tropical Thraustochytrid Aurantiochytrium Sp. Umacc-T023 In Submerged-Liquid Fermentation For Large-Scale Biodiesel Production, Sohedein Mohamad Nor Azzimi Jul 2020

Optimisation Of Biomass And Lipid Production Of A Tropical Thraustochytrid Aurantiochytrium Sp. Umacc-T023 In Submerged-Liquid Fermentation For Large-Scale Biodiesel Production, Sohedein Mohamad Nor Azzimi

Student Works (2020-2029)

A tropical thraustochytrid, Aurantiochytrium sp. UMACC-T023, was optimised for high biomass and lipid production in submerged-liquid fermentation (SLF). Biomass and lipid production were optimised based on glucose, polypeptone, and yeast extract concentration using response surface methodology (RSM). In RSM, the applied central composite design (CCD) showed that the optimisation model was significant for all variables studied. Yeast extract and polypeptone were associated with significant effects in UMACC-T023 biomass production with p < 0.05. The model was validated by employing the optimised media composition in shake flasks and in 1.4-L stirred-tank bioreactors. The optimised media composition for both biomass and lipid production was 10 g L-1 glucose, 15.08 g L-1 polypeptone, and 13.56 g L-1 yeast extract. Biomass production in the bioreactor increased 2.12-fold compared with the shake flask culture utilising the same optimised media composition. This result demonstrated that the optimized media composition can be utilised for large-scale lipid production of UMACC-T023 for potential biodiesel feedstock as it also fulfilled the international standards for biodiesel.

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Identification And Characterization Of Genes Influencingwssvdisease Resistance In Giant Tiger Shrimp (Penaeus Monodon) Using A Transcriptomicsapproach, Mohd Ghani Farhana Jul 2020

Identification And Characterization Of Genes Influencingwssvdisease Resistance In Giant Tiger Shrimp (Penaeus Monodon) Using A Transcriptomicsapproach, Mohd Ghani Farhana

Student Works (2020-2029)

The giant tiger shrimp (Penaeus monodon) is one of the most extensively farmed crustacean species in the world. The emergence of diseases such as the white spot syndrome virus has however become a threat to the shrimp industry. Although there have been various studies utilizing RNA-Seq, more efforts are needed to further understand the molecular mechanisms of host-virus interaction in P. monodon. The effect of the WSSV infection on host gene expression in the haemocytes, hepatopancreas and muscle of P. monodon was investigated using Illumina HiSeq 2000. The RNA-Seq of cDNA libraries was developed from survived WSSV-challenged shrimp as well …

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Suspended Carbon Nanowire Biosensor For Rapid And Label-Free Salmonella Detection, Thiha Aung Jul 2020

Suspended Carbon Nanowire Biosensor For Rapid And Label-Free Salmonella Detection, Thiha Aung

Student Works (2020-2029)

Carbon, the building block life, is rapidly becoming the building block of nextgeneration electronics and sensor materials. Of many ways to handle nanocarbon materials, Carbon Microelectromechanical Systems (C-MEMS) emerges as a unique way for top-down fabrication of three-dimensional carbon micro to nanostructures. In this work, the use of C-MEMS techniques in nanowire biosensor fabrication is explored. Two main hindrances in the use of C-MEMS carbon structures for biosensing lie in miniaturization to nanoscale sensor material and inertness of as-fabricated carbon. This dissertation presents ways to overcome these limitations. First, miniaturization to patterned sub-100 nm carbon nanowires was achieved by optimization …

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Meeting Report Of The Third Annual Tri-Service Microbiome Consortium Symposium, J Philip Karl, Robyn A. Barbato, Laurel A. Doherty, Aarti Gautam, Sarah M. Glaven, Robert J. Kokoska, Dagmar Leary, Rebecca Mickol, Matthew A. Perisin, Andrew J. Hoisington, Edward J. Van Opstal, Vanessa Varaljay, Nancy Kelley-Loughnane, Camilla A. Mauzy, Michael S. Goodson, Jason W. Soares Jul 2020

Meeting Report Of The Third Annual Tri-Service Microbiome Consortium Symposium, J Philip Karl, Robyn A. Barbato, Laurel A. Doherty, Aarti Gautam, Sarah M. Glaven, Robert J. Kokoska, Dagmar Leary, Rebecca Mickol, Matthew A. Perisin, Andrew J. Hoisington, Edward J. Van Opstal, Vanessa Varaljay, Nancy Kelley-Loughnane, Camilla A. Mauzy, Michael S. Goodson, Jason W. Soares

Faculty Publications

The Tri-Service Microbiome Consortium (TSMC) was founded to enhance collaboration, coordination, and communication of microbiome research among U.S. Department of Defense (DoD) organizations and to facilitate resource, material and information sharing among consortium members. The 2019 annual symposium was held 22–24 October 2019 at Wright-Patterson Air Force Base in Dayton, OH. Presentations and discussions centered on microbiome-related topics within five broad thematic areas: 1) human microbiomes; 2) transitioning products into Warfighter solutions; 3) environmental microbiomes; 4) engineering microbiomes; and 5) microbiome simulation and characterization. Collectively, the symposium provided an update on the scope of current DoD microbiome research efforts, highlighted …

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Bioinformatic Analysis Of The Gut Microbiota Derived From The Oil Fly Helaeomyia Petrolei From The La Brea Tar Pits, Brian A. Dillard Jul 2020

Bioinformatic Analysis Of The Gut Microbiota Derived From The Oil Fly Helaeomyia Petrolei From The La Brea Tar Pits, Brian A. Dillard

School of Biological Sciences: Dissertations, Theses, and Student Research

In the early 1930s, Thorpe a prominent entomologist, called for more research into Helaeomyia petrolei larva. These larvae live in the Californian La Brea tar pits where they are exposed to large amounts of polyaromatic hydrocarbons. Molecules like anthracene, phenanthrene, and toluene which should be highly toxic to both the oil fly larvae and its enteric bacteria. This extremophilic gut microbiome has yet to be studied using current day next gen sequencing and bioinformatic techniques. In fact, since Thorpe’s work in the 1930s, there have been only two publications characterizing the oil fly larvae. Both in the early 2000s by …

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Phenotypic Switching Of Bacterial Cells In Extreme Environments, Sudip Nepal Jul 2020

Phenotypic Switching Of Bacterial Cells In Extreme Environments, Sudip Nepal

Graduate Theses and Dissertations

A large number of terrestrial microbial lives thrive in extremes of environmental conditions, including extremes of pressure, temperature, salinity, pH, and a combination of them. For example, all the marine biomass thrive at high hydrostatic pressure depending on depth. The temperature in the ocean can be very high near the hydrothermal vents and salinity and pH depends on the composition of salt in the surrounding areas. On the surface, hot springs, lakes and geysers provide high temperature conditions, while many places are permafrost regions with subzero temperatures. There is an emerging body of work on the viability, genomics, and metagenomics …

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Current Epidemiological Assessment Of Plasmodium Falciparum And Helminth Co-Infections In Children After A Decade Of Implementation Of Control Programs In Morogoro Region, Tanzania, Christopher Kisiringyo, Winifrida Kidima Jun 2020

Current Epidemiological Assessment Of Plasmodium Falciparum And Helminth Co-Infections In Children After A Decade Of Implementation Of Control Programs In Morogoro Region, Tanzania, Christopher Kisiringyo, Winifrida Kidima

Tanzania Journal of Science

A school based cross-sectional study was conducted from July to November 2018 to assess the burden of asymptomatic Plasmodium falciparum, Schistosoma and soil transmitted helminth (STH) infections in Mvomero. A total of 374 children (age range =  5–16 years, mean age = 11.3 years) were recruited from five primary schools. Prevalence of asymptomatic P. falciparum infections were 29.9%, S. haematobium 49.7%, hookworm 20.3%, Ascaris lumbricoides 12.6%, Taenia saginata 0.5% and S. mansoni 0.3%. Malaria parasite density increased with increasing children age (r = 0.99). Only 6.5% (12/186) of S. haematobium infected children were presented with heavy infections, whereas all STH-positive …

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Geochemical Characteristics Of Soil In Relation To Occurrence Of Entomopathogenic Nematodes (Epns) In Osogbo, Osun State, Nigeria, Mohammed Rufai, Abidat Shittu, Monsuru Adeleke Jun 2020

Geochemical Characteristics Of Soil In Relation To Occurrence Of Entomopathogenic Nematodes (Epns) In Osogbo, Osun State, Nigeria, Mohammed Rufai, Abidat Shittu, Monsuru Adeleke

Tanzania Journal of Science

The occurrence and abundance of entomopathogenic nematodes (EPNs) vary across locations, and this has been attributed to many factors including soil physico-chemical properties. This study examined the influence of selected soil chemicals on the occurrence of EPNs under different cultivated lands in Osun state, Southwestern Nigeria. EPNs were isolated from 23.33% of the soil samples in selected sites using decantation and centrifugation method and nematodes observed under standard microscopy were identified based on morphological analysis of infective juveniles (IJs). This study has revealed the presence of nematodes of the families Steinernema and Heterorhabditis in the sampled soils. Soil chemical properties, …

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Assessment Of Biochemical Changes During Fermentation Process For Production Of Traditional Fermented Cassava Meal “Mchuchume”, Severino Alphonce, Lilian Kaale Jun 2020

Assessment Of Biochemical Changes During Fermentation Process For Production Of Traditional Fermented Cassava Meal “Mchuchume”, Severino Alphonce, Lilian Kaale

Tanzania Journal of Science

“Mchuchume” is a ready to eat fermented cassava food whose production is accomplished by a consortium of microorganisms, some of which may be probiotic in nature and others pathogens to humans and of no use in the fermenting system. This work made characterization of biochemical changes evolved at different times in local (open) and biotechnological (closed) fermentation methods. The study also assessed organoleptic properties of final products. Acidification was observed in the retting water as pH ranged from 6.32 to 4.25 and titratable acidity from 0.02% to 0.32%. A decrease in total reducing sugars (6.59 to 4.03 mg/g) in fermenting …

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Antimicrobial Strategies For Topical Applications, Kelsey Marie Lopez Jun 2020

Antimicrobial Strategies For Topical Applications, Kelsey Marie Lopez

LSU Doctoral Dissertations

Bacteria can thrive in diverse environments and are often harmless or beneficial. Bacteria in digestive tracts is one example of beneficial bacteria; however, bacteria can be harmful and when this type proliferates, it can cause infections within hosts. Bacterial infections are easily treated with antibiotics in most cases. However, bacteria are also capable of developing mutations which could cause them to become multi-drug resistant and eventually, “superbugs.” Therefore, the development of novel antimicrobial agents and materials capable of combating drug-resistant bacteria is necessary. Research presented in this dissertation focuses on different strategies for minimizing and preventing topical bacterial infections using …

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Microbial Community Structures In Three Bahamian Blue Holes, Meghan J. Gordon Jun 2020

Microbial Community Structures In Three Bahamian Blue Holes, Meghan J. Gordon

USF Tampa Graduate Theses and Dissertations

This study used 16S rDNA metagenomics and water chemistry to conduct an examination of microbial community dynamics and biogeochemistry in three physically adjacent, sunlit blue holes with variable hydrologic regimes on San Salvador Island, Bahamas. Church and Watling’s Blue Holes are holomictic with relatively clear waters, while Inkwell Blue Hole hosts density stratification and waters stained brown with tannins. Based on water color and clarity and physicochemical profiles, I hypothesized Church and Watling’s Blue Holes would be dominated by oxigenic photoautotrophs, and that the bottom layer of Inkwell would be characterized by euxinic (anoxic and sulfidic) conditions and host primarily …

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Plant Defensin Antibacterial Mode Of Action Against Pseudomonas Species, Andrew E. Sathoff, Shawn Lewenza, Deborah A. Samac Jun 2020

Plant Defensin Antibacterial Mode Of Action Against Pseudomonas Species, Andrew E. Sathoff, Shawn Lewenza, Deborah A. Samac

Research & Publications

Background: Though many plant defensins exhibit antibacterial activity, little is known about their antibacterial mode of action (MOA). Antimicrobial peptides with a characterized MOA induce the expression of multiple bacterial outer membrane modifications, which are required for resistance to these membrane-targeting peptides. Mini-Tn5- lux mutant strains of Pseudomonas aeruginosa with Tn insertions disrupting outer membrane protective modifications were assessed for sensitivity against plant defensin peptides. These transcriptional lux reporter strains were also evaluated for lux gene expression in response to sublethal plant defensin exposure. Also, a plant pathogen, Pseudomonas syringae pv. syringae was modified through transposon mutagenesis to …

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The Clinical Features Of Co-Circulating Dengue Viruses And The Absence Of Dengue Hemorrhagic Fever In Pakistan, Erum Khan, Dhani Prakoso, Kehkashan Imtiaz, Faisal Malik, Joveria Farooqi, Maureen T. Long, Kelli L. Barr Jun 2020

The Clinical Features Of Co-Circulating Dengue Viruses And The Absence Of Dengue Hemorrhagic Fever In Pakistan, Erum Khan, Dhani Prakoso, Kehkashan Imtiaz, Faisal Malik, Joveria Farooqi, Maureen T. Long, Kelli L. Barr

Department of Pathology and Laboratory Medicine

Dengue virus (DENV) is the most common and widespread arboviral infection worldwide. Though all four DENV serotypes cocirculate in nature, the clinicopathological framework of these serotypes is undefined in Pakistan. A cross-sectional, observational study was performed to document the circulation of various arboviruses in the Sindh region of Pakistan. Here we describe a population of patients diagnosed with DENV spanning a 2-year period. This study used an orthogonal system of NS1 antigen ELISA followed by RT-PCR for DENV detection and subtyping. A total of 168 NS1 positive patients were evaluated of which 91 patients were serotyped via RT-PCR. There was …

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Microbiomes Of Caribbean Octocorals Vary Over Time But Are Resistant To Environmental Change, Mark Mccauley, Colin R. Jackson, Tamar Goulet Jun 2020

Microbiomes Of Caribbean Octocorals Vary Over Time But Are Resistant To Environmental Change, Mark Mccauley, Colin R. Jackson, Tamar Goulet

Faculty and Student Publications

The bacterial microbiome is an essential component of many corals, although knowledge of the microbiomes in scleractinian corals far exceeds that for octocorals. This study characterized the bacterial communities present in shallow water Caribbean gorgonian octocorals over time and space, in addition to determining the bacterial assemblages in gorgonians exposed to environmental perturbations. We found that seven shallow water Caribbean gorgonian species maintained distinct microbiomes and predominantly harbored two bacterial genera, Mycoplasma and Endozoicomonas. Representatives of these taxa accounted for over 70% of the sequences recovered, made up the three most common operational taxonomic units (OTUs), and were present in …

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Metabolic Network Analysis Of Filamentous Cyanobacteria, Daniel Alexis Norena-Caro Jun 2020

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 …

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Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein Jun 2020

Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein

Honors Scholar Theses

In recent years, ciprofloxacin resistant (CpR) Aeromonas veronii and A. hydrophila strains have been isolated from the wounds of patients receiving leech therapy. Genome comparisons of these CpR isolates revealed the presence of chromosomal mutations in gyrA and parC as well as the gain of qnrS2 on either a large, 34 kb, conjugatable, low-copy plasmid, pAv42, or on a small, 6.8 kb, high-copy plasmid, pAh1471. The minimum inhibitory concentration, MIC, for Cp of these clinical isolates ranged from 1 to ≥32 µg/mL and some harbored a qnrS2 containing plasmid. We wanted to assess the contributions of these factors in an …

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Roadmap For Naming Uncultivated Archaea And Bacteria, Alison E. Murray, John Freudenstein, Simonetta Gribaldo, Roland Hatzenpichler, Philip Hugenholtz, Peter Kämpfer, Konstantinos T. Konstantinidis, Christopher E. Lane, R. Thane Papke, Donovan H. Parks, Ramon Rossello-Mora, Matthew B. Stott, Cameron Thrash, Stephanus N. Venter, William B. Whitman, Silvia G. Acinas, Rudolf I. Amann, Karthik Anantharaman, Jean Armengaud, Brett J. Baker, Roman A. Barco, Helge B. Bode, Eric S. Boyd, Carrie L. Brady, Paul Carini, Patrick S. G. Chain, Daniel R. Colman, Kristen M. Deangelis, Maria Asuncion De Los Rios, Paulina Estrada-De Los Santos, Christopher A. Dunlop Jun 2020

Roadmap For Naming Uncultivated Archaea And Bacteria, Alison E. Murray, John Freudenstein, Simonetta Gribaldo, Roland Hatzenpichler, Philip Hugenholtz, Peter Kämpfer, Konstantinos T. Konstantinidis, Christopher E. Lane, R. Thane Papke, Donovan H. Parks, Ramon Rossello-Mora, Matthew B. Stott, Cameron Thrash, Stephanus N. Venter, William B. Whitman, Silvia G. Acinas, Rudolf I. Amann, Karthik Anantharaman, Jean Armengaud, Brett J. Baker, Roman A. Barco, Helge B. Bode, Eric S. Boyd, Carrie L. Brady, Paul Carini, Patrick S. G. Chain, Daniel R. Colman, Kristen M. Deangelis, Maria Asuncion De Los Rios, Paulina Estrada-De Los Santos, Christopher A. Dunlop

Life Sciences Faculty Research

The assembly of single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) has led to a surge in genome-based discoveries of members affiliated with Archaea and Bacteria, bringing with it a need to develop guidelines for nomenclature of uncultivated microorganisms. The International Code of Nomenclature of Prokaryotes (ICNP) only recognizes cultures as ‘type material’, thereby preventing the naming of uncultivated organisms. In this Consensus Statement, we propose two potential paths to solve this nomenclatural conundrum. One option is the adoption of previously proposed modifications to the ICNP to recognize DNA sequences as acceptable type material; the other option creates a nomenclatural code …

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