Microbiology Commons^™

Exploring Anaerobic Reductive Dechlorination At Low Ph Environments, Yi Yang

Masters Theses

Chlorinated aliphatic hydrocarbons (CAHs), such as tetrachloroethene (PCE) and trichloroethene (TCE), are ubiquitously pollutants in aquifer sediments and groundwater due to their heavy usage in industry and inappropriate disposal in the last century. Among about 1300 NPL (National Priorities List) sites, PCE and TCE are the two most frequently detected hazardous contaminants.

Engineered bioremediation, including biostimulation and bioaugmentation, is a promising technology to clean those PCE and/or TCE contaminated sites. However, in many contaminated groundwater systems and hazardous waste sites, pH can be lower than 5 to 6. And release of HCl (strong acid) from anaerobic reductive dechlorination may lower …

Applied And Mechanistic Studies Of Microbial 17beta-Estradiol Degradation, Zhongtian Li

Z Li

The presence of natural estrogens, a class of endocrine disrupting compounds, in water has caused increasing concerns over their adverse impacts on the health of aquatic eco-systems and human beings. In this study, adsorption characteristics of two natural estrogens, 17β-estradiol (E2) and estrone (E1), on granular activated carbon (GAC) were investigated in isotherm tests and in a GAC column. The GAC column was then converted to a biologically active carbon (BAC) column and the removal efficiency of E2 and its primary biodegradation intermediate E1 were monitored. During BAC operation, the impacts of various reactor operation parameters, such as the carbon …

Inactivation Of Bacterial Opportunistic Skin Pathogens By Nonthermal Dc-Operated Afterglow Atmospheric Plasma, L. C. Heller, C. M. Edelblute, A. M. Mattson, X. Hao, J. F. Kolb

Bioelectrics Publications

AIMS: Multidrug-resistant opportunistic pathogens are clinically significant and require the development of new antimicrobial methods. In this study, Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus cells were exposed to atmospheric plasma on agar plates and in vitro on porcine skin for the purpose of testing bacterial inactivation.

METHODS AND RESULTS: Microbial inactivation at varying exposure durations was tested using a nonthermal plasma jet generated with a DC voltage from ambient air. The observed reduction in colony forming units was quantified as log₁₀ reductions.

CONCLUSIONS: Direct plasma exposure significantly inactivated seeded bacterial cells by approx. 6 log_{10 …}

Comparison Of Phenolic Compounds And Antioxidant Capacities Of Traditional Sorghum Beers With Other Alcoholic Beverages, Fatouma Abdoul-Latif, Romaric G. Bayili, Louis C. Obame, Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

Thirty samples of sorghum beers “dolo” were selected from traditionally fermented household manufacturers from Burkina Faso. Dolo samples were screened for their total phenolic content, proanthocyanidins and putative antioxidant capacities, and were compared with industrial beers and wines. Total phenols were measured using the Folin-Ciocalteu method. Proanthocyanidins content were determined by the method of HCl-butanol hydrolysis. Antioxidant activities were evaluated both with 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and by the trolox equivalent antioxidant capacity (TEAC) using 2,2’-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid radical) (ABTS•+). The average contents of total phenols and proanthocyanidins were 506 μg GAE/ml of dolo and 45 μg APE/ml of dolo, respectively. An …

Characterization Of Xylan Utilization And Discovery Of A New Endoxylanase In Thermoanaerobacterium Saccharolyticum Through Targeted Gene Deletions, Kara K. Podkaminer, Adam M. Guss, Heather L. Trajano, David A. Hogsett, Lee R. Lynd

Dartmouth Scholarship

The economical production of fuels and commodity chemicals from lignocellulose requires the utilization of both the cellulose and hemicellulose fractions. Xylanase enzymes allow greater utilization of hemicellulose while also increasing cellulose hydrolysis. Recent metabolic engineering efforts have resulted in a strain of Thermoanaerobacterium saccharolyticum that can convert C5 and C6 sugars, as well as insoluble xylan, into ethanol at high yield. To better understand the process of xylan solubilization in this organism, a series of targeted deletions were constructed in the homoethanologenic T. saccharolyticum strain M0355 to characterize xylan hydrolysis and xylose utilization in this organism. While the deletion of …

Toxicity Assessment And Analgesic Activity Investigation Of Aqueous Acetone Extracts Of Sida Acuta Burn F. And Sida Cordifolia L. (Malvaceae), Medicinal Plants Of Burkina Faso, Kiessoum Konate, Adama Hilou, Raïssa Rr Aworet-Samseny, Alain Souza, Nicolas Barro, Mamoudou H. Dicko Prof., Jacques Datté, Bertrand M’Batchi

Pr. Mamoudou H. DICKO, PhD

Background Sida acuta Burn f. and Sida cordifolia L. (Malvaceae) are traditionally used in Burkina Faso to treat several ailments, mainly pains, including abdominal infections and associated diseases. Despite the extensive use of these plants in traditional health care, literature provides little information regarding their toxicity and the pharmacology. This work was therefore designed to investigate the toxicological effects of aqueous acetone extracts of Sida acuta Burn f. and Sida cordifolia L. Furthermore, their analgesic capacity was assessed, in order to assess the efficiency of the traditional use of these two medicinal plants from Burkina Faso. Method For acute toxicity …

Effects Of Moisture Augmentation Of Municipal Solid Waste Through Addition Of Food Waste Or Wastewater Treatment Biosolids On Bio-Gas Formation For Power Generation, Jared Michael Gore

UNLV Theses, Dissertations, Professional Papers, and Capstones

An investigation into the effect of moisture augmentation by manipulation of food waste proportion or wastewater treatment plant biosolids proportion was undertaken to determine the effects on production of methane and other biogases from municipal solid waste (MSW). Laboratory microcosm experiments were performed to determine the effect of various proportions of influent waste streams on the production of biogas. Results indicated that moisture augmentation through the addition of food waste to MSW increases the overall bio-gas and hydrogen gas formed during fermentation. Moisture augmentation through addition of wastewater treatment bio-solids lead to inconclusive results. Addition of food waste to MSW …

Antibacterial Activity Against Beta- Lactamase Producing Methicillin And Ampicillin-Resistants Staphylococcus Aureus: Fractional Inhibitory Concentration Index (Fici) Determination, Kiessoun K Onate, Jacques François Mavoungou, Alexis Nicaise Lepengué, Raïssa Rr Aworet-Samseny, Adama Hilou, Mamoudou H. Dicko Prof., Bertrand M’Batchi

Pr. Mamoudou H. DICKO, PhD

The present study reports the antibacterial capacity of alkaloid compounds in combination with Methicillin and Ampicillin-resistants bacteria isolated from clinical samples. The resistance of different bacteria strains to the current antibacterial agents, their toxicity and the cost of the treatment have led to the development of natural products against the bacteria resistant infections when applied in combination with conventional antimicrobial drugs. The antibacterial assays in this study were performed by using inhibition zone diameters, MIC, MBC methods, the time-kill assay and the Fractional Inhibitory Concentration Index (FICI) determination. On the whole, fifteen Gram-positive bacterial strains (MRSA/ARSA) were used. Negative control …

Enhanced Hydrocarbon Biodegradation Using Bioaugmentation With Biowish™-Aqua Fog, Michael Robert Lehrer

Master's Theses

This study was done to determine the effectiveness of a commercially available bioaugmentation product, BiOWiSH^TM-Aqua FOG, for remediating petroleum-contaminated sandy soil. Biodegradation enhancement by BiOWiSH^TM-Aqua FOG was evaluated in laboratory microcosms by directly measuring total petroleum hydrocarbon (TPH) and indirectly using respirometry. Attempts were made to enrich hydrocarbon-degrading bacteria in BiOWiSH^TM-Aqua FOG, and the resulting enrichment cultures were screened using respirometry as well. Potential hydrocarbon-degrading bacteria in BiOWiSH^TM-Aqua FOG were isolated. Experiments were performed at bench-scale using microcosm bottles containing sand contaminated with either motor oil or No. 2 diesel fuel. The …

Proteomic Analysis Of 17Β-Estradiol Degradation By Stenotrophomonas Maltophilia, Zhongtian Li

Z Li

Microbial degradation plays a critical role in determining the environmental fate of steroid hormones, such as 17β-estradiol (E2). The molecular mechanisms governing the microbial transformation of E2 and its primary degradation intermediate, estrone (E1), are largely unknown. The objective of this study was to identify metabolism pathways that might be involved in microbial estrogen degradation. To achieve the objective, Stenotrophomonas maltophilia strain ZL1 was used as a model estrogen degrading bacterium and its protein expression level during E2/E1 degradation was studied using quantitative proteomics. During an E2 degradation experiment, strain ZL1 first converted E2 to E1 stoichiometrically. At 16 h …

Investigation Of Bacillus Subtilis As A Biopesticide Against Botrytis Cinerea, Kenneth K. Ng

Master's Theses

The objective of this thesis was to investigate BiOWiSH^TM-Aqua, a commercial dry solid formulation containing a consortium of bacteria and yeast, as a biopesticide for treatment of Botrytis cinerea, a gray mold that affects strawberries. BiOWiSH^TM-Aqua was compared with another commercial product specifically used as a fungicide and bacteriocide, Serenade® Garden Disease Control Spray (concentrated Bacillus subtilis strain QST 713). Both laboratory tests as well as in vivo lab tests were conducted. BiOWiSH^TM-Aqua results varied widely from plate to plate, regardless of experimental conditions. In some of these plates, inhibition zones were observed …

Removing 17Β-Estradiol From Drinking Water In A Biologically Active Carbon (Bac) Reactor Modified From A Granular Activated Carbon (Gac) Reactor, Zhongtian Li

Z Li

Estrogenic compounds in drinking water sources pose potential threats to human health. Treatment technologies are needed to effectively remove these compounds for the production of safe drinking water. In this study, GAC adsorption was first tested for its ability to remove a model estrogenic compound, 17β-estradiol (E2). Although GAC showed a relatively high adsorption capacity for E2 in isotherm experiments, it appeared to have a long mass transfer zone in a GAC column reactor, causing an early leakage of E2 in the effluent. With an influent E2 concentration of 20 μg/L, the GAC reactor was able to bring down effluent …

Bacteriocin Formation By Dominant Aerobic Sporeformers Isolated From Traditional Maari, Donatien Kabore, Line Thorsen, Dennis Sandris Nielsen, Torben Sune Berner, Hagrétou Sawadogo-Lingani, Bréhima Diawara, Mamoudou H. Dicko Prof., Mogens Jackobsen

Pr. Mamoudou H. DICKO, PhD

The antimicrobial activity of 8 Bacillus spp. and 2 Lysinibacillus spp. representing the predominant aerobic sporeformers during traditional maari fermentations, a traditional fermented baobab seeds product fromBurkina Faso,was investigated. The antimicrobial activitywas assessed against a total of 31 indicator organisms representing various Gram-negative and positive pathogens. The screening showed that 3 Bacillus subtilis strains (B3, B122 and B222) in particular had antimicrobial activity against some Gram-positive organisms and were selected for further studies. Itwas found that the antimicrobial substances producedwere heat stable, in-sensitive to catalase, sensitive to protease and trypsin but resistant to the proteolytic action of papain and proteinase …

Acid Resistance, Bile Tolerance And Antimicrobial Properties Of Dominant Lactic Acid Bacteria Isolated From Traditional “Maari” Baobab Seeds Fermented Condiment, Donatien Kabore, Hagrétou Sawadogo-Lingani, Mamoudou H. Dicko Prof., Bréhima Diawara, Mogens Jacobsen

Pr. Mamoudou H. DICKO, PhD

Maari is a fermented food condiment obtained by spontaneous fermentation of seeds from the baobab tree (Adansonia digitata). Nine dominant lactic acid bacteria (LAB) strains, isolated from traditional maari fermentation were examined for their resistance to pH 2.5, their tolerance to 0.3% bile and their antimicrobial activities against pathogenic bacteria. The agar spot test was used to screen the dominant LAB for antagonistic activity against a total of 21 indicator organisms including Bacillus cereus strains, Salmonella spp., Listeria monocytogenes, Yersinia enterocolitica, Escherichia coli and Micrococcus luteus. It was observed that all LAB strains survived in 0.3% bile and exhibited antimicrobial …

Why Do We Collect?, Allison Marsh

Section 2: Imaging the Microscopic

No abstract provided.

Imaging And Aesthetics, Allison Marsh

Section 2: Imaging the Microscopic

No abstract provided.

Capturing Motion, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.

Understanding Fracture, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.

Listen, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.

Photographic Evidence, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.

Spotlight On Usc: Mechanical Engineering, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.

Influencing Art, Allison Marsh

Section 3: Imaging the Fast Moving

No abstract provided.

Complete Genome Sequence Of Clostridium Clariflavum Dsm 19732, Javier A. Izquierdo, Lynne Goodwin, Karen W. Davenport, Hazuki Teshima

Dartmouth Scholarship

Clostridium clariflavum is a Cluster III Clostridium within the family Clostridiaceae isolated from thermophilic anaerobic sludge (Shiratori et al, 2009). This species is of interest because of its similarity to the model cellulolytic organism Clostridium thermocellum and for the ability of environmental isolates to break down cellulose and hemicellulose. Here we describe features of the 4,897,678 bp long genome and its annotation, consisting of 4,131 protein-coding and 98 RNA genes, for the type strain DSM 19732.

Spotlight On Usc: A.C. Moore Herbarium, Allison Marsh

Section 2: Imaging the Microscopic

No abstract provided.

Virus Capsids As Nanoscale Delivery Vessels Of Photoactive Compounds For Site-Specific Photodynamic Therapy, Brian Alexander Cohen

Legacy Theses & Dissertations (2009 - 2024)

The research presented in this work details the use of a viral capsid as an addressable delivery vessel of photoactive compounds for use in photodynamic therapy. Photodynamic therapy is a treatment that involves the interaction of light with a photosensitizing molecule to create singlet oxygen, a reactive oxygen species. Overproduction of singlet oxygen in cells can cause oxidative damage leading to cytotoxicity and eventually cell death. Challenges with the current generation of FDA-approved photosensitizers for photodynamic therapy primarily stem from their lack of tissue specificity. This work describes the packaging of photoactive cationic porphyrins inside the MS2 bacteriophage capsid, followed …