Environmental Microbiology and Microbial Ecology Commons^™

Imidacloprid Effects On The Survival And Cutaneous Microbiome Of Northern Leopard Frogs, Evelyn Margaret Osterloo

Honors Thesis

Amphibians are experiencing population declines due to habitat loss, climate change, and diseases, particularly chytridiomycosis caused by the fungus Batrachochytrium dendrobatidis. Protection from this fungal infection stems from the cutaneous microbiome. Pesticides have been shown to affect amphibians in a variety of ways, including reducing survival, locomotor performance, and accumulation in body tissues. Pesticides may also lead to changes in the cutaneous microbiome affecting amphibians who rely on these organisms as an anti-Bd defense mechanism. To investigate the effect of imidacloprid, a neonicotinoid insecticide, Northern Leopard frogs (Lithobates pipiens) were subjected to sublethal concentrations (control = …

Enhancing Urban Garden Capacity By Linking Biodiversity And Ecosystem Function, Mary T. Nguyen, Carleen Rauh, Shelby Gresch, Charlotte Correiro, Heidi Elmendorf, Adriane Fugh-Berman, Gina Wimp, Alexandra L. Decandia

Virginia Journal of Science

Urban agriculture broadly describes food and plant cultivation in metropolitan areas. While biodiversity is thought to support ecosystem health and resilience, the relationship between above-ground and below-ground diversity has been understudied in urban green spaces. This study examines plant, animal, bacterial, and fungal diversity across three distinct urban habitats: a turf lawn, a forb garden, and a farming space. Using bacterial 16S rRNA and fungal ITS2 sequencing, soil nutrient analyses, and surveys of vegetation and wildlife, we connect diverse philosophies in urban agriculture to their role in advancing community diversity and ecosystem function. We found that different urban gardens support …

Lead Biosorption By Oceanobacillus Profundus Kbz 3-2: Strategies For Bioremediation Systems In Kabwe, Danielle S. Desmarteau

Scripps Senior Theses

Lead contamination remains a significant global public health concern, particularly in Kabwe, Zambia, the site of a former lead mining operation. Bioremediation, which utilizes biological materials and processes to remove environmental contaminants, represents a promising approach for addressing lead pollution. However, the development of effective bioremediation systems requires a detailed understanding of the mechanisms underlying metal removal and the feasibility of implementation in low-resource settings. Oceanobacillus profundus KBZ 3-2, a bacterium isolated from Kabwe mine waste, has demonstrated the ability to remove lead from aqueous environments. This study proposes to investigate the mechanism of lead biosorption by this organism, …

Environmental Monitoring In Shallow Lakes: Public Health Threats In Urban Waters, Kyleigh E. Johnson

Theses and Dissertations

Lakes are an integral part of urban and suburban communities, providing ecological, recreational, and public health benefits. Many of these lakes are located in densely populated areas and are subject to urban influences on water quality. Algal toxins and Escherichia coli are two common recreational concerns. Algal toxins come from harmful algal blooms that are influenced by nutrient availability and temperature, while bacteria are often introduced through run-off and animal waste. Sampling every 3-4 weeks from May-October 2025 allowed for the assessment of seasonal patterns and site-specific differences across nine lakes in the Richmond area. The highest bacterial concentrations appeared …

Microplastic Exposure Alters Tubulin Leading To Alterations In Insulin Secretion By Pancreatic Beta Cells, Anakaren Garcia

Honors Program Theses and Research Projects

Abstract

Diabetes mellitus is a metabolic disorder characterized by elevated blood glucose levels due to impaired insulin secretion or diminished cellular response to insulin (resistance). Pancreatic β-cells depend on a well-organized cytoskeleton, particularly microtubules composed of α- and β-tubulin heterodimers, to transport insulin granules to the plasma membrane during glucose-stimulated insulin secretion (GSIS). Disruption of microtubule organization can impair granule trafficking and reduce insulin release. However, emerging environmental toxicants such as microplastics that interfere with β-cell cytoskeletal function remains largely unexplored.

Microplastics (MPs) are small plastic particles (< 5 mm) that have become widespread environmental contaminants and can enter biological systems. Previous studies have shown that MPs can induce cellular stress and protein misfolding, but their effects on microtubules in pancreatic β-cells are not well characterized. This study investigates whether exposure to fluorescent polystyrene microplastics alters microtubule organization and insulin secretion in βTC-6 cells.

βTC-6 cells were treated with 10 µg/mL of fluorescent polystyrene microplastics for …

First Report Of A Bat Guano Fire From A Cave In Southeast Asia, Sopark Jantarit, Martin Ellis, Pruet Kalasuwan, Neeranuch Phusunti, Pimonsri Mittraparp-Arthorn, Jiranan Pattano, Arnon Chukamnerd, Turdtun Tong-In, Natthawut Khrueaaunruean

International Journal of Speleology

Fires occurring in cave guano are a rare and unusual phenomenon and the occurrence of such events in Southeast Asia is particularly novel. In this study, we document the first recorded instance of a bat guano fire in a tropical cave at Tham Chao Ram in Sukhothai province, northern Thailand. A bacteriological analysis was made of the guano at the fire site and from a control site within the cave. We give a comprehensive review of global reports on bat guano fires in caves, conduct an initial investigation of the physical factors at the fire site and discuss the potential …

Microbial Biodiversity Of The James River Rock Pool Ecosystem., Jordan C. Heydt

Masters Theses, 2020-current

Rock pools are ephemeral aquatic environments that offer a unique opportunity to study complex communities and their responses to environmental changes. The urban James River rock pool system consists of over 700 individual rock pools varying in size and depth. This unique urban freshwater ecosystem has been studied for its invertebrate, plant, and zooplankton populations but not for its microbial community composition. To fill that gap, the microbial community of this system was characterized using 16S rRNA gene sequencing, and the influence of environmental variables on the community composition was analyzed. Our findings show variation in microbial community composition across …

Biological Reduction Of Perchlorate In Martian Regolith Simulant Using Azospira Oryzae, Brianna Bernhardt

Honors Program: Senior Projects (Public)

Establishing a sustainable human presence on Mars will require in-situ resource utilization (ISRU) to reduce costly and inefficient resupply missions. Despite containing many of the requirements for agriculture, Martian regolith is contaminated with toxic levels of perchlorate (ClO₄^-), threatening human health and agricultural success. Biological remediation using perchlorate-reducing bacteria offers a promising approach to address these challenges. This study investigated the perchlorate-reducing ability of Azospira oryzae, a facultative anaerobe capable of converting ClO₄^- to chloride (Cl^-) through dissimilatory respiration. A. oryzae was cultured in Martian regolith simulant (MGS-1) amended with 0.0%, 0.5%, …

Investigating Drivers In Phytoplankton Between Lentic And Lotic Ecosystems Within Twelvepole Creek Watershed, Devin Lee Farmer

Theses, Dissertations and Capstones

Harmful Algal Blooms (HABs) threaten aquatic ecosystems, local economies, and water quality. While extensively studied in lakes (lentic systems), their impact on flowing waters (lotic systems) remains underexplored. This study examined algal drivers in both ecosystems within the same watershed, focusing on Beech Fork Lake (lentic) and Twelve Pole Creek (lotic). Key environmental factors, including pH, turbidity, dissolved oxygen, and nutrient levels, were measured using in situ sensors and laboratory analysis. Water samples were analyzed for nitrogen, phosphorus, and algal biomass for comparison to environmental conditions. Phytoplankton was preserved for identification in future research. By comparing these environments, this study …

Using Bivalves As An Indicator For Fecal Bacteria, Kamala Chuss

Honors Scholar Theses

This project focuses on the integration of fecal bacteria from warm-blooded animals into bivalve tissue, and the utilization of bivalves as an indicator for fecal bacteria in waterways. Bivalves may give a more representative long-term average of fecal bacteria in water as compared to direct water testing. The primary objective is to create a standard operating procedure to use bacterial testing of bivalves as a proxy for bacteria concentration in the water. This method can be used in places where bivalves do not already exist by adding them to a body of water, or by collecting bivalves that already exist …

Assessment Of Tce And Chiral Pcb Dechlorination Rate, Congener Diversity, And Enantioselectivity In Town Creek, Sc, Usa Sediment Microcosms, Catherine P. Sumner

All Dissertations

Polychlorinated biphenyls (PCBs) and trichloroethene (TCE) are ubiquitous contaminants and are recognized as persistent organic pollutants due to their extreme chemical stability. PCBs were manufactured by chlorinating biphenyls that created 209 congeners with various structures, of which 19 are chiral and can exist as a pair of stable atropisomers. PCBs have been known to cause developmental and neurological toxicity in humans and wildlife; they can act as endocrine disrupters, carcinogens, and teratogens. Sangamo Weston Inc. was an industrial plant located near Town Creek in Pickens Country, South Carolina, that manufactured capacitors and used Aroclors 1016 and 1254 as dialectic fluids …

Degradation Of Chlorpyrifos Residue On Tropical Inceptisol Soil With Indigenous Bacteria Treatment, Asep Kurnia, Hidayatuz Zu`Amah, Baiq Nunung Sulastri, Ria Fauriah Makmur

Makara Journal of Science

The use of soil microbes is one of the most effective methods for degrading pesticide residue in soil. Microbes can accelerate the degradation of persistent pollutants including chlorpyrifos in soil. This research aims to find soil bacteria with the greatest potential to degrade chlorpyrifos residue in tropical inceptisol soil and determine its degradation index (DI). The soil used in this experiment was collected from agricultural fields in the districts of Demak, Central Java Province, Indonesia. The experiment was performed using factorial randomize complete block design composed of two factors and four replications. The first factors were made up of two …

Validation Of A Passive Sampler For Tracking Harmful Algal Toxins In Natural Waters, Hailee Eiker

Honors Theses

Algal blooms that produce toxins that are harmful to the health of people, animals, and the environment are known as harmful algal blooms (HABs). Recently, rising global temperatures, nutrient pollution, and an increase in the frequency of extreme hydrologic events have made HABs a bigger problem. This has all led to greater cultural eutrophication which is a major contributor to the spread of HABs. Cyanobacteria make up the bulk of HABs in freshwater systems, microcystins being among the cyanotoxins that are most frequently reported and studied. Taking grab samples of water is the current standard procedure for sampling cyanotoxins, however, …

Interactions Between Multiple Stressors, Nanomaterials And A Pathogen, In Caenorhabditis Elegans, Jarad Cochran

Theses and Dissertations--Plant and Soil Sciences

Metal and metal oxide nanoparticles (NP), which have received interest for use in agriculture, show in vitro and in vivo toxicity at relatively low concentrations. Silver nanoparticles (Ag NP) and zinc oxide nanoparticles (ZnO NP) cause adverse effects in model soil organisms under environmentally relevant conditions. In most toxicity assessments of nanomaterials, model organisms are exposed to a single stressor. Though single stressor experiments are essential to understanding the fate and effects of released NP, in nature, organisms are affected by multiple stressors, including pathogens, which might exacerbate or mitigate negative effects of NP exposure. There is limited research on …

Effects Of Subchronic Oral Pfos Exposure Via Drinking Water On Gut Microbiota Composition, Emma Ann Loder

Graduate Theses/Dissertations

Perfluorooctanesulfonic acid (PFOS) has been phased out of production in the United States, but because of its resistance to degradation and its persistence in the environment, PFOS can be found in drinking water across America. Oral exposure to PFOS has been linked to adverse developmental, immunological, hepatic, and endocrine health. Oral PFOS exposure may alter the gut microbiota and cause dysbiosis, which is implicated in the pathology of inflammatory diseases like Crohn’s disease, diabetes, and ulcerative colitis. The goal of the study was to investigate the effects of subchronic oral PFOS exposure on the composition of the gut microbiota. Adult …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

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 …

Effect Of Authentic Kefir And Nigella Sativa On Broilers Challenged By Coccidia And Clostridium Perfringens, Julian E. Nixon

All Dissertations

Black seed oil concentrations of 0%, 0.1%, 1% and 5% were added to milk inoculated with kefir grains and incubated at 25°C for 22 h. The pH and microbial count indicated 1% black seed oil caused low inhibition (P > 0.05) of fermentation, but 5% black seed oil caused significant inhibition of the kefir microorganisms (P < 0.05).

Cobb 500 male chicks (n = 256) were distributed in a randomized block design and received one of four treatments: CTRL1 (Non-medicated, no kefir, no Clostridium perfringens), CTRL2 (Non-medicated, no kefir, C. perfringens inoculated), CTRL3 (BMD medicated, no kefir, C. perfringens inoculated), KTRT (Non-medicated, …

The Presence Of Microcystin In The Northwest Indiana Watershed, Breeann Mild

The Journal of Purdue Undergraduate Research

No abstract provided.

Evaluating Soil Health Changes Following Cover Crop And No-Till Integration Into A Soybean (Glycine Max) Cropping System In The Mississippi Alluvial Valley, Alexandra Gwin Firth

Theses and Dissertations

The transition of natural landscapes to intensive agricultural uses has resulted in severe loss of soil organic carbon (SOC), increased CO₂ emissions, river depletion, and groundwater overdraft. Despite negative documented effects of agricultural land use (i.e., soil erosion, nutrient runoff) on critical natural resources (i.e., water, soil), food production must increase to meet the demands of a rising human population. Given the environmental and agricultural productivity concerns of intensely managed soils, it is critical to implement conservation practices that mitigate the negative effects of crop production and enhance environmental integrity. In the Mississippi Alluvial Valley (MAV) region of Mississippi, USA, …

Diversity Of Bacteriophage In Burkholderia Species, Abigail Price

Honors Projects

Bacteriophages are viruses that infect and replicate within bacteria and offer the potential of a therapeutic alternative to chronic infections that do not respond to antibiotic-based therapies. B. vietnamiensis is one of a number of Burkholderia species involved with chronic drug resistant infections in the lungs of individuals with compromised respiratory systems, as found in those with chronic obstructive pulmonary disease and, most especially, are of particular significance in patients with cystic fibrosis. The diversity of the Burkholderia species is explored by using online databases and looking at bacteriophage or phage-encoding viruses found in B. vietnamiensis. The open reading frames …

Assessing Environmental Factors That Influence Cyanobacterial Blooms In Skinn Lake, Kloe Atwood

Honors Projects

Global lakes are experiencing an increase in toxic algal blooms that can be damaging to the environment. These blooms are caused by cyanobacteria, specifically a species called Planktothrix. Skinn Lake, in Ohio, is a location of a cyanobacterial bloom that is mainly populated by Planktothrix rubescens. This lake was further examined to identify the major toxin-producing bacteria and identify environmental microbes surrounding the bloom. When the data was examined it was found that the microbiomes of the lake greatly differed between the winter (bloom) months and the summer (non-bloom) months. This difference can be viewed within the nutrient analysis from …

Plastic Biodegradation Through Insects And Their Symbionts Microbes: A Review, Huda Bilal, Hasnain Raza, Haseena Bibi, Tehmina Bibi

Journal of Bioresource Management

Plastic waste has recently been identified as one of the most serious environmental issues, affecting all life forms, natural habitats, and the economy, and is one of the most serious global environmental problems, second only to climate change. Seeking alternative environmentally sustainable options, such as biodegradation instead of conventional disposal, is critical in the face of this challenge. However, there is currently a lack of information about the mechanisms and efficacy of plastic biodegradation. From this perspective, this study aims to illustrate the negative environmental impacts of the plastic waste. It also addresses the role of insects and gut microbiota …

Investigating Distribution Of Legionella Pneumophila In Urban And Suburban Watersheds, Azlan Maqbool

Student Theses

The presence of Legionella pneumophila was assessed using a cultivation-based approach in New York City waterways, a freshwater portion of the lower Hudson River Estuary near Kingston NY, and in urban and suburban street water. Legionella pneumophila was detected in 51% of brackish New York City Estuary samples, most with concentrations near minimum detection (=>1 organism/ mL). In contrast, it was detected in 22% of suburban freshwater Hudson River Estuary samples. Levels of the bacterium were found to be higher during wet weather compared to dry weather in the highly dense urban setting, but not in the less dense …

Microbiological Study In A Gneissic Cave From Sri Lanka, With Special Focus On Potential Antimicrobial Activities, Ethige Isuru P. Silva, Pathmakumara Jayasingha, Saman Senanayake, Anura Dandeniya, Dona Helani Munasinghe

International Journal of Speleology

The emergence of antibiotic resistance is a global health crisis, thus the search for novel antimicrobial compounds has become a continuous necessity. Underexplored and extreme environments, such as cave ecosystems, have been identified as a promising potential source for the discovery of novel microorganisms with novel antimicrobial compounds (AMC). This study presents the first cave microbiological investigation in Sri Lanka, with a special preference for bioprospecting of novel AMC. The cave sediment characterization demonstrated the presence of close to strong acidic conditions (pH 3.1 – 3.3) and thus indicates the possibility of isolating acidophilic microorganisms. Eight cave wall/ceiling fungal strains …

Inhibition Of Biofilm Formation By The Synergistic Action Of Egcg-S And Antibiotics, Shrameeta Shinde, Lee Lee, Tinchun Chu

Department of Biology Faculty Scholarship and Creative Works

Biofilm, a stress-induced physiological state, is an established means of antimicrobial tolerance. A perpetual increase in multidrug resistant (MDR) infections associated with high mortality and morbidity have been observed in healthcare settings. Multiple studies have indicated that the use of natural products can prevent bacterial growth. Recent studies in the field have identified that epigallocatechin gallate (EGCG), a green tea polyphenol, could disrupt bacterial biofilms. A modified lipid-soluble EGCG, epigallocatechin-3-gallate-stearate (EGCG-S), has enhanced the beneficial properties of green tea. This study focuses on utilizing EGCG-S as a novel synergistic agent with antibiotics to prevent or control biofilm. Different formulations of …

Determining The Effects Of Imidacloprid On Non-Target Soil Organisms In Hemlock Stands, Braley Burke

Graduate Theses, Dissertations, and Problem Reports (ETD)

The hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), is an invasive insect that is causing mortality of eastern hemlock trees, Tsuga canadensis, and Carolina hemlock trees, Tsuga caroliniana, across the eastern United States. To protect these ecologically important tree species, a neonicotinoid insecticide, imidacloprid, is commonly used. Imidacloprid is an effective treatment and can remain effective against HWA for four to six years but long-term (≥ one year after application) non-target effects of imidacloprid on forest ecosystems are not well-studied. This study examined terrestrial non-target effects of imidacloprid in hemlock stands with different treatment histories to …

Inaction On Lead Despite The Relevant Knowledge: Predictors, Covariates, And Outreach Implications, Alessandra Rossi, Bernabas Wolde, Pankaj Lal, Melissa Harclerode

Department of Biology Faculty Scholarship and Creative Works

Testing residential soil and paint for lead provides actionable information. By showing where and how much lead exists on the residence, it allows one to quantify risk and determine the best ways to reduce exposure along with the corresponding health and financial costs. For these reasons, several federal and state programs offer outreach to audiences on the benefits of testing residential soil and paint for lead. Not all individuals who know about lead’s adverse health effects, however, test their residence for lead, potentially limiting the actionable information that could have helped to reduce their exposure. Such individuals represent a challenge …

Aspergillus Niger Decreases Bioavailability Of Arsenic(V) Via Biotransformation Of Manganese Oxide Into Biogenic Oxalate Minerals, Bence Farkas, Marek Kolenčík, Miroslav Hain, Edmund Dobročka, Gabriela Kratošová, Marek Bujdoš, Huan Feng, Yang Deng, Qian Yu, Ramakanth Illa, B. Ratna Sunil, Hyunjung Kim, Peter Matúš, Martin Urík

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The aim of this work was to evaluate the transformation of manganese oxide (hausmannite) by microscopic filamentous fungus Aspergillus niger and the effects of the transformation on mobility and bioavailability of arsenic. Our results showed that the A. niger strain CBS 140837 greatly affected the stability of hausmannite and induced its transformation into biogenic crystals of manganese oxalates—falottaite and lindbergite. The transformation was enabled by fungal acidolysis of hausmannite and subsequent release of manganese ions into the culture medium. While almost 45% of manganese was bioextracted, the arsenic content in manganese precipitates increased throughout the 25-day static cultivation of fungus. …

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 …