Environmental Microbiology and Microbial Ecology Commons^™

Monitoring Lake Sinclair, Margaret Blackledge

Graduate Research Showcase

Algae, a polyphyletic group of aquatic primary producers, play a great part in earth’s biosphere. They produce half of the world’s oxygen and are major contributors to aquatic biodiversity. When conditions are favorable to a species, algae will bloom. Some algal species will produce algal toxins during a bloom as a potential mechanism to concentrate carbon. Due to the integral part they play in aquatic food webs, nutrient cycling and the potential for harmful algal blooms, algal communities are monitored to determine the health and safety of aquatic environments. Lake Sinclair in middle Georgia is a good model where in …

Choices On Sampling, Sequencing, And Analyzing Dna Influence The Estimation Of Community Composition Of Plant Fungal Symbionts, Jonathan A. Cale, Natalie Scott, Gregory J. Pec, Simon M. Landhäusser, Justine Karst

Publications: Biology

Plant root symbionts, namely mycorrhizal fungi, can be characterized using a variety of methods, but most of these rely on DNA. While Sanger sequencing still fulfills particular research objectives, next‐generation sequencing currently dominates the f ield, thus understanding how the two methods differ is important for identifying both opportunities and limitations to characterizing fungal communities. In addition to testing sequencing methods, we also examined how roots and soils may yield different fungal communities and how disturbance may affect those differences. We sequenced DNA from ectomycorrhizal fungi colonizing roots of Pinus banksiana and found that operational taxonomic unit richness was higher, …

Characterization Of Microbial Populations In Landfill Leachate, Umut M. Bicim, Hanna Fulford, Lori A. Hoagland, Alejandro R. Sanchez, Amisha D. Shah, Inez Hua

Discovery Undergraduate Interdisciplinary Research Internship

In the United States, municipal solid waste (MSW) landfills remain a potential mining source of recoverable materials, including but not limited to critical, precious, and rare earth metals found in electronic waste. This is possible due to collectible leachate that filters through MSW landfills, carrying metals, nutrients of value, and microbes—some of which may hold key metal bioleaching properties—within. The purpose of this study is to begin analyzing leachate from MSW landfills in the American Midwest to understand the composition of microbial communities within these landfills. Landfill leachate samples sourced in northern Indiana, representing the landfill process during unique times …

Roles Of Non-Frankia Bacteria In Root Nodule Formation And Function In Alnus Sp., Kelsey Christine Mercurio

Honors Theses and Capstones

Plant roots are home to a wide variety of beneficial microbes; understanding and optimizing plant-microbe interactions may be critical to enhance global food security in a sustainable, equitable way. With the help of their nitrogen-fixing bacterial partner, Frankia, actinorhizal plants form symbiotic root nodules and play important roles in agroforestry and land reclamation. However, Frankia does not live alone in nodules, and the other microbial residents may contribute to nodule formation and function. We collected root nodules from alder trees (Alnus sp.) in 2018 and 2019, then isolated DNA and individual bacterial strains to characterize the nodule microbial …

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 …

Impact Of Endangered Animal Protection Rights, Policies, And Practices On Zoonotic Disease Spread, Daniella Fedak-Lengel

Honors Projects

Building on field research in Costa Rica and Belize, this honors project analyzes environmental and endangered animal protection policies, rights, and practices in Central America and the Caribbean, and assesses the impact of veterinary science and biological research and practice, particularly conservation biology, on animal welfare concerns. Informed by the recent surge in awareness regarding zoonoses and zoonotic disease transmission, prevention and control, resulting from the current global pandemic of SARS-CoV-2, the project assesses the need for new and innovative types of collaboration, particularly involving conservation biologists, environmental scientists, public health experts, law and policy makers, and global trade and …

Spatio-Temporal Dynamics Of Fungal Communities And Their Effects On Plants, Kel Cook

Biology ETDs

Fungi perform several critical functions in the environment. Spatiotemporal distributions of fungal communities will mediate when and where these functions happen and how they vary across the landscape. I first explored tropical tree canopy fungal community variation at small spatial scales and documented near total turnover of fungi across sub-meter distances and among adjacent substrates. The second chapter analyzed fungal turnover over the course of three years, where community stability was driven primarily by abundant fungi. In the third chapter, I tested effects of the environment, including host plant and habitat, on canopy fungal communities and found only small effects, …

Evaluation Of Anti-Cancer Function In Natural Killer Cells Generated From Rat Hematopoietic Stem Cells, Alireza Pirahmadian

Student Works (2020-2029)

Natural killer cells (NK) cells are lymphocytes and they are the most important key constituent of mammalian immune system against cancer tumour cells. The genome of NK cells is categorically divided to inhibitory and activator genes that code ligands on the surface of NK cells. Indeed, these ligands are cancer tumour cells destroyer arms of the NK cells. On the other hand, hematopoietic stem cells (HSCs) are the origin of all blood cells, derives from BM and mature to immune cells. NK cells cannot defeat CTCs on their own. The main reason is their population (numbers are low), they cannot …

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. …

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. …

The Trichoplusia Ni Gut Microbiome And Its Derivation From The Phyllosphere Of Its Food Plants, Josemaria Garcia, Marisol Escanuela, Swapna Bhat, Evan Lampert

Georgia Journal of Science

Insects are the most abundant and diverse animals on planet Earth and rely on their diverse microbiomes to be so. The insect gut microbiome is vital in the growth and development of many insect species. Trichoplusia ni, the cabbage looper, is a generalist herbivore, but little is known about its microbiome. In this study, a metagenomic analysis of fecal samples was used to determine the effect of diet on the microbiome of T. ni larvae. Larvae were reared on six plant species, the microbiome was sampled from fecal material, and the phyllosphere was sampled from leaves the larvae ate. …

Diatom Voucher Flora And Comparison Of Collection Methods For Biodiversity Hotspot Upper Three Runs Creek, Katie M. Johnson

Biology Theses

Surface freshwater is a scarce resource. Due to the scarcity and necessity of this resource, it is imperative that its quality is routinely monitored. One way of monitoring water quality is through biological assessments, which include examining algal assemblages. Regionally, little remains known of algal taxa in the southeastern United States. In the past, the Academy of Natural Sciences of Philadelphia (ANSP) conducted biological assessments along the Savannah River finding Gomphonema parvulum (Kützing) Kützing 1849 to be a dominant taxon rendering assessments inconclusive. Recent studies have provided evidence that species complexes and semi-cryptic taxa have been identified within the Gomphonema …

Identification Of Antibiotic Producing Soil Bacteria Against Bacillus Subtilis, Morgan Brockhouse, Dr. Lori Scott

Identifying and Characterizing Novel Antibiotic Producing Microbes From the Soil

This project is a collaboration with the Tiny Earth Project Initiative (TEPI), which is a global network of educators and students focused on student-sourcing antibiotic discovery from soil. Individual strains of soil bacteria were isolated and produced antibiotic against Bacillus subtilis. Two of these samples were sequenced using the 16S rRNA gene to reveal they are very closely related to the genus Pseudomonas.

Massard Prairie Restoration And Soil Microbiome Succession, Jeffrey M. Shaver, Emily S. Bellis, Chizuko Iwaki, Jake Qualls, Jay Randolph, Jeremiah Smith

Journal of the Arkansas Academy of Science

We have initially sequenced soil microbial DNA from 4 restored and 4 virgin tallgrass prairie soil samples from Ben Geren Park and Massard Prairie (Fort Smith, AR), respectively. As expected, the soil microbiomes are distinct, with several lineages of nitrogen-fixing bacteria more common in virgin tall grass prairie. However, we predict that as restoration of tallgrass prairie in Ben Geren Park progresses, the soil microbiome of restored prairie will more closely mirror those of the virgin prairie.

Investigating Links Between Soil Microbial Structure And Function In Three Major Plant Communities Across Temporal Scales Of Arctic Alaska, Kaj Lynoe

Electronic Theses and Dissertations

Arctic microbial systems continue to get attention today as our understanding regarding their structure and function in a changing system is paramount to C feedbacks with warming and changes in precipitation. Plant communities and microbial community processes across the Arctic landscape are central to understanding tundra ecosystem processes because environmental conditions and plant community structure drive microbial cycling of soil organic matter. Here, we want to understand how soil microbial respiration, mineralization, biomass, and community composition are linked to three Alaskan tundra plant communities, namely Shrub, Tussock, and Sedge tundra and the seasonal variability in this system. A total of …

Biocide Resistance As A Result Of Exposure To Biocides Used In Hydraulic Fracturing, Lindsey Schenten

Dissertations, Master's Theses and Master's Reports

Microbial resistance to antimicrobials is an important topic to investigate not only for our health but for the environment. There is a growing concern about expanding microbial resistance to both antibiotics and other antimicrobials such as biocides. We wanted to know how bacteria previously exposed to hydraulic fracturing fluids, including biocides, would react to biocide exposure and what the mechanism of resistance looked like. In order to test this hypothesis bacterial isolates were obtained from water and sediment from a stream that had been previously exposed to a spill of hydraulic fracturing water. Thirty bacterial isolates were obtained from these …

A Landscape On The Threshold Of Change: Patterns Of Soil Microbial Ecology Along Dynamic Geomorphic And Hydrologic Features In A Polar Desert, Kelli L. Feeser, David James Van Horn, Heather N. Buelow, Daniel R. Colman, Theresa A. Mchugh, Jordan G. Okie, Egbert Schwartz, Cristina D. Takacs-Vesbach, Becky A. Ball, Andrew G. Fountain, Michael N. Gooseff, Joseph S. Levy, Maciej K. Obryk

Biology ETDs

The McMurdo Dry Valleys (MDV) of Antarctica are on the threshold of widespread landscape scale change due to increasing temperature and solar radiation and altered hydrology: buried ice is melting, the soil active layer is thickening, thermokarst features are developing along streams, water tracks are expanding, and lake levels are rising. These changes will impact the microbial communities found in each of the affected habitats. The purpose of this work is to first, understand the spatial distribution of soil bacteria in the MDV, specifically investigating the scale-dependent effects of environmental heterogeneity, and second, to perform surveys and coupled experiments to …

Interaction Between Fusarium Head Blight And Crown Rot Disease Incidence And Environmental Factors And Soil Physiochemical Analysis On Wheat In The South Of Iraq, Basra Province, Mohammed Hussein Minati Dr., Mohanad Khalaf Mohammed-Ameen Dr.

Karbala International Journal of Modern Science

This study was conducted to evaluate the interaction between disease incidence of both Fusarium head blight (FHB) and crown rot (FCR) and physiochemical parameters for soil samples and environmental factors in 14 selected wheat fields in the North of Basra province. The results showed that both diseases were occurred in all surveyed fields. The level of FCR incidence was higher than FHB. The incidence of both diseases was increased with favourable weather conditions (high humidity and temperature ˃15 °C), reaching the highest levels in crucial periods before and during the ripening stage. The percentage of disease incidence ranged between 6 …

Morphology, Molecular Characterization And Habitat Preference Of Harmful Benthic Dinoflagellate Gambierdiscus (Dinophyceae) In Malaysia, Nurin Izzati Mustapa

Student Works (2020-2029)

Ciguatera fish poisoning (CFP) is a type of illness that causes human intoxication after consuming contaminated coral fishes. The neurotoxins, ciguatoxins, are produced by species of Gambierdiscus, one of the harmful benthic dinoflagellates. Identification of harmful dinoflagellate species is important to gain further insights into the global dispersion. In this study, morphological characteristics of species in the genus Gambierdiscus and their habitat preferences were investigated. Field sampling was undertaken at Pulau Rawa, Terengganu and Pulau Sibu, Johor. Single cells of Gambierdiscus were isolated and clonal cultures were established. Morphology of Gambierdiscus was examined by using light and scanning electron microscopes. …

Glycolic Acid Utilization In Two Species Of Marine Bacteria, Erik S. Timsak

STAR Program Research Presentations

Interactions between bacteria and phytoplankton are crucial for the cycling of organic matter in marine environments. Around 50% of organic carbon taken up by marine bacteria is converted into inorganic carbon. The uptake of organic carbon by marine bacteria exuded from phytoplankton is a key factor in regulating the marine carbon cycle. One such molecule that is exuded by phytoplankton and then uptaken by marine bacteria is called glycolate - the anion of glycolic acid, a two caron molecule. Glycolate is exuded by phytoplankton during photorespiration and 10-50% of dissolved organic carbon in marine environments is comprised of glycolate. Additionally, …

Molecular Detection Of Pathogenic Leptospira Throughout The Caribbean, Zamara R. Garcia Truitt

Biology Theses

Leptospirosis is a common widespread zoonotic disease found throughout the Caribbean. The infection is produced by a pathogenic Leptospira species found in tropical and subtropical regions. The severity of the disease ranges from a mild asymptomatic infection to death. Leptospirosis is a neglected tropical disease due to the lack of public awareness and health approaches. Therefore, misdiagnosis is common because the symptoms are similar to that of other tropical endemic diseases. The aim of the study was to determine the presence of pathogenic Leptospira in water samples collected from Puerto Rico and Trinidad. Sixty-four environmental water samples were collected throughout …

Hawk On Wire: Ecopoems By Scott T. Starbuck, Vivian M. Hansen

The Goose

Review of Scott T. Starbuck’s Hawk on Wire: Ecopoems

Investigation Of Origin And Growth Of Fungi In Coastal Beach Sand, Ruth L. Wright

Honors Theses

In a previous study from this lab (Stevens, Evans, & Aguirre, 2012) yeast colonies were isolated and grown grown from sand collection at pristine, medium use and high use beaches along the grand strand. In that study greater yeast abundance and greater diversity both correlated with higher census of human use, suggesting that some yeast growth of sites was anthropogenic. However the sand matrix itself also varied from very fine, uniform, dark sand at the pristine beach to coarser, color varying, less tightly packed sand at residential and commercial beaches. This suggested an alternative hypothesis to differential colonization and growth …

Fungi In A Hot, Dry, Changing World, Miriam I. Hutchinson

Biology ETDs

My doctoral work focused on understanding the reciprocal relationship between fungi and their environment, namely how fungi respond to environmental flux, as well as how fungi can modify and structure their habitats, especially in the context of climate change. As such, I aimed my research on fungi with distinct adaptations to their environmental niches: endophytic fungi that inhabit plant tissue and thermophilic fungi that are capable of growing at the upper temperature limit for eukaryotic life. My research consisted of three studies. First, I investigated the thermophilic species Myceliophthora heterothallica to demonstrate its use as a model organism for efficient …

Warming Up: Climate Change Related Shifts Of Mycorrhizal Fungal Communities In High Latitude Ecosystems, Megan Rae Devan

Biology ETDs

This dissertation examines how climate change affects mycorrhizal fungal communities in boreal and arctic ecosystems. In chapter one, I revealed that increases in fire severity and related increases in deciduous tree dominance result in greater Ascomycota relative abundance (RA) and subsequent declines in Basidiomycota RA. In chapter two I analyzed the effects of post-fire mycorrhizal fungal communites on host growth. There were trends at the fungal genus level that were largely reflected at the guild level across all hosts; however, there were some fungal genera that had the opposite effect on different host species. In chapter three, I found host …

Identification Of Bird-Associated Nonpoint Sources Of Microbial Contamination In Sediments, Savannah D. Mullins

Honors College Theses

Fecal indicator bacteria (FIB), such as Enterococci, are commonly used to monitor the microbial contamination of recreational beach waters based on standards set by the United States Environmental Protection Agency. Sediment and sand may also harbor FIB and reintroduce these bacteria to the water column. Enterococci may be originated from various non-point sources such as humans and wildlife. Recent literature has shown that avian feces also harbor high concentrations of Enterococci. The purpose of this study is identify the relationship between Enterococci and avian-associated markers in sediments. Sediment samples were collected monthly from four sites at Kings Ferry Beach in …

Consistency Is Futile!: Selecting Phycoremediators For Consortia, Tori Spencer

BIO 410 Spring 2019 Research Papers

Bioremediation is the process by which organisms remove and transform toxic compounds in a contaminated source. This is a waste management technique currently used to clean up man-made contamination. Many organisms act as natural remediators; in the case of algae, they are called phycoremediators who perform phycoremediaton. The term algae encompasses a variety of taxonomic groups and their diversity is still being realized; there are over 44,000 named species of the 72,000 species that we have identified. Some estimates calculate that there are over 200,000 diatom species alone. This diversity continues to be difficult to organize, which is problematic for …

Combating Drug Resistance - Comparison Of The Antibiotic Effect Of Hydrastis Canadensis Extract And Pure Berberine Via Minimum Inhibitory Concentration Assay, William Luke Scott, Timothy D. Trott

Research in Biology

Herbal medicines are a melee of complex organic chemicals, making it difficult to ascertain their direct mechanism of action. In contrast to mainstream pharmaceuticals, it is argued that herbal medicines are effective because of multiple constituents working synergistically. The complexity of herbal medicines may give them advantages over simpler pharmaceuticals in combating antibiotic resistant microbes, but these advantages can be difficult to quantitate. Popular literature frequently espouses the healing properties of herbal medicines, but many of these claims are not scientifically supported. Many gains could be realized in public health and medicine if more research was aimed at validating / …

Genomics Based Approaches To Fungal Evolution, Aaron J. Robinson, Donald O. Natvig

Biology ETDs

Advances in DNA sequencing and data analysis make it possible to address questions in population genetics and evolution at the genomic level. Fungi are excellent subjects for such studies, because they are found in diverse environments, have short generation times, can be maintained in culture and have relatively small genomes. My research employed genetic approaches using a variety of sequencing technologies and methods of analysis to explore questions in fungal evolution.

In one study, I explored the genetics behind differences in thermotolerance between isolates of Neurospora discreta from Alaska and New Mexico. Isolates from the two states exhibited differences in …

High-Throughput Cultivation Of Bacterioplankton From The Gulf Of Mexico And Genomics Of The First Cultured Ld12 Representative, Michael Winslow Henson

LSU Doctoral Dissertations

Cultivation of microorganisms facilitates characterization of metabolism, interspecies dependencies, virus-host interactions, and other information necessary to resolve the functions and distribution of individual taxa. However, the metabolic and physiological capacities for the majority of microbes remains unresolved because of the lack of cultivated representatives for many groups limits our ability to test cultivation-independent observations. The Northern Gulf of Mexico offers a diversity of ecosystems under the continuous threat from natural and anthropogenic disturbances, yet little is known about its native bacterioplankton community. This dissertation sought to use high-throughput cultivation over three-years at six sites to isolate important coastal bacteria to …