Environmental Microbiology and Microbial Ecology Commons^™

“Pinkalicious": Outer Membrane Vesicles Isolated From Pseudoalteromonas Rubra Carry Prodigiosin Antibiotics As Cargo, Margaret Hill

Senior Honors Projects

Astrangia poculata, the state coral of Rhode Island, is susceptible to infection by Vibrio coralliilyticus RE22, which is a common marine pathogen affecting various invertebrate species. The settlement of coral larvae prior to the establishment of colonies is mediated by crustose coralline algae (CCA). This process may be induced by CCA-associated protective bacteria that colonize corals in early metamorphosis; furthermore, such bacteria potentially have downstream effects in the susceptibility of corals to pathogens. Strains of Pseudoalteromonas rubra isolated from CCA have been shown to induce larval settlement of tropical corals. We hypothesize that P. rubra induces the settlement of …

Investigating The Impact Of Edaphobacter Aggregans (Wbg-1) On Arabidopsis Thaliana Development, Julia Talbert

Undergraduate Research Symposium

Acidobacteria is a phylum of bacteria that make up 50% of soil microbes. While making up a large proportion of bacteria found in soil, this phylum is largely unexplored with limited information about the bacteria and their impact on plant growth. The selected target of this study is Edaphobacter aggregans, WBG-1, which is a part of a subdivision of acidobacteria. Examining the bacteria’s effects on the development of the model plant Arabidopsis thaliana will provide insight into understanding this unknown phylum of soil-dwelling bacteria. Acidobacteria are an important realm to investigate as they affect agriculture practices. With Missouri being such …

Analysis Of Microbial Abundance On Marine Snow In The Deep Ocean, Matthew Qilan Thompson

Undergraduate University Honors Capstones

The ocean plays a critical role in the carbon cycle, with phytoplankton serving as a source of energy and nutrients (such as nitrogen and phosphorus) to larger organisms in upper trophic levels. Additionally, marine snow, a cluster of components including dead zooplankton, organic carbon debris, and polymers as carbohydrates, proteins, and DNA, transport these nutrients and associated microorganisms to the deeper parts of the ocean. However, the relationship between microbial abundance and particle sizes of marine snow across the water column is not well understood. Previous studies suggest that microbial abundance is lower in the bathypelagic zone (1,000m - 4,000m) …

A Forensic Assessment Of Current Water Quality Using Idexx Techniques In The Himmarshee Canal And New River In Fort Lauderdale, Florida, Catherine Margaret Bilodeau

All HCAS Student Capstones, Theses, and Dissertations

Fecal contamination has continued to plague local communities around the United States and the world, especially in highly populated areas like Southern Florida. Newer techniques are beginning to be used to track microbes properly as they are found in waterways. Some more recent techniques in Microbial Source Tracking (MST) use IDEXX kits to detect fecal indicator bacteria (FIB). Two IDEXX kits Colilert-18^® which detects total coliforms and Escherichia coli in water or fecal coliforms in wastewater, and Enterolert^®, which targets enterococci, were used in the waterways of the Himmarshee Canal and South Fork of the New River …

Effects Of Cyanobacteria Harmful Algal Blooms On The Microbial Community Within Lake Okeechobee, Fl, Usa, Paisley S. Samuel

All HCAS Student Capstones, Theses, and Dissertations

The Lake Okeechobee (Lake O) watershed is a Floridian freshwater ecosystem that has been affected by the increased frequency and intensity of harmful cyanobacterial bloom (cyanoHAB) events occurring over recent decades. Lake O has several ecological and economic purposes such as providing habitats for various organisms and providing drinking water to urban communities surrounding the lake. Toxic cyanoHAB events are posing a threat to the ecosystem and economy of the lake due to the degradation of water quality. This study investigates how the microbial community structure within Lake O is affected by annual cyanobacterial harmful algal blooms over several years …

The Application Of Microbial Source Tracking To Aid In Site Prioritization For Remediation In Lower Michigan, John J. Hart

Masters Theses

Non-point source fecal pollution is a threat to both the environment and public health. Climate change, aging infrastructure, and intensified agricultural practices are predicted to accentuate this issue. In Michigan, due to the high instance of aging infrastructure and intensified agriculture, non-point source fecal pollution has caused many waterbodies to exceed the state standards posing a risk to recreational activities and source water. Due to this threat, there is an increased effort to identify and remediate these sources. My study focused on improving the identification of non-point source fecal pollution through a combination of culture-based and molecular fecal indicator bacteria …

Microbial Community Interactions Between Honey Bee Symbionts, Jillian P. Lewis

2023 Midwest Ecology & Evolution Conference

Bombella apis is a bacterial honey bee symbiont that benefits larvae by supplementing their nutrition and protecting them from pathogenic fungi. B. apis co-occurs with another bee-associated bacterium, Apilactobacillus kunkeei, in certain hive niches: nectar, larvae, honey stomachs of nurse bees, the queen gut, and royal jelly. Because bacterial species existing in the same ecological niche are apt to form microbial communities that interact, these interactions may modulate B. apis’ positive impact on the honey bee larvae. We hypothesize that due to its faster growth, A. kunkeei outcompetes B. apis for shared resources in nutrient rich conditions such …

Variation In Synthetic Floral Microbiome Composition Is Largely Ignored By Foraging Bumblebees, Nevin P. Cullen

2023 Midwest Ecology & Evolution Conference

Most flowers are occupied by diverse communities of microbes, which can alter floral attractiveness to key pollinators and floral fitness by interacting with floral traits. Different species of flower often acquire unique communities of microbes. Consequently, pollinators are frequently forced to choose between two flowers with distinct floral microbiomes while foraging. However, it is currently unknown whether pollinators have an inherent preference for flowers containing one floral microbiome over another, and whether microbial preference is modified by variation in floral traits. We investigated this knowledge gap using distinct bacteria and yeasts cultured from a nickel-hyperaccumulating plant and its non-accumulating relative. …

An Optimal Patch Use Model For Nitrogen Foraging In Arbuscular Mycorrhizal Fungi, Xin Lin

2023 Midwest Ecology & Evolution Conference

Optimal Foraging Theory has been widely used to study animal foraging behaviors, but has seldom been applied to symbiotic microbes like arbuscular mycorrhizal (AM) fungi. To date we know little about how AM fungi make decisions to forage in different nutrient patches. To help address this gap we here apply Optimal Foraging Theory to understand how AM fungi forage for nitrogen. We focus on nitrogen because AM fungi need more nitrogen than their plant hosts and soil nitrogen availability can shift the relationship between AM fungi and their hosts from mutualism to parasitism. We present a stochastic dynamic programming model …

Elevated Co2 Drives Community And Network Structural Change Within Foliar Microbiomes Of Soybean, Connor Morozumi

2023 Midwest Ecology & Evolution Conference

Microbiomes within plants can play large roles in determining responses to stress or perturbation, increasingly common in a rapidly changing world. For example, foliar endophytes are known to increase stress tolerance to drought and decrease herbivory among many other effects. How these microbes are likely to respond to global change themselves is poorly understood. Global changes, such as increased atmospheric CO₂, which can influence host plant physiological processes, have the potential to directly and indirectly alter microbiome community structure. Here, we assessed community and network structure of bacterial and fungal phyllosphere microbiomes within soybean (Glycine max). …

Initial Steps In Testing The Stress Gradient Hypothesis For Selenium Exposure In Soil Bacteria, Kristian J. Harris

2023 Midwest Ecology & Evolution Conference

The Stress Gradient Hypothesis (SGH) states that interspecific interactions should shift from competitive to facilitative interactions as environmental stress increases. Selenium (Se) is a naturally occurring metalloid that acts as an environmental pollutant and as an essential micronutrient. Due to its metallic properties, Se acts as an oxidative stress and can be toxic to plants and animals. Given this, Se in soil systems acts as an abiotic stress that influences species composition and species interactions. Within soils, bacteria and fungi have evolved to tolerate Se via detoxification and Se processing for respiration and studies show that metal detoxification traits like …

Human Microbiome Transfer In The Built Environment Differs Based On Occupants, Objects, And Buildings, Andrew J. Hoisington, Christopher E. Stamper, Katherine L. Bates, Maggie A. Stanislawski, Michael C. Flux, Teodor T. Postolache, Christopher A. Lowry, Lisa A. Brenner

Faculty Publications

Compared to microbiomes on other skin sites, the bacterial microbiome of the human hand has been found to have greater variability across time. To increase understanding regarding the longitudinal transfer of the hand microbiome to objects in the built environment, and vice versa, 22 participants provided skin microbiome samples from their dominant hands, as well as from frequently and infrequently touched objects in their office environments. Additional longitudinal samples from home environments were obtained from a subset of 11 participants. We observed stability of the microbiomes of both the hand and built environments within the office and home settings; however, …

Enrichment Media Selection And Co-Culture Potential Among Exoelectrogen Bacteria Vary With Ecological Factors, Nur Syafira Khoirunnisa, Syaiful Anwar, Untung Sudadi, Dwi Andreas Santosa

Makara Journal of Science

Staphylococcus saprophyticus ICBB 9554 and Citrobacter freundii ICBB 9763 are exoelectrogen bacteria applied as microbial fuel cells (MFC). We selected enrichment media for both these exoelectrogen bacteria, characterized their synergistic traits, and evaluated the growth conditions under different ecological factors. In this study, different enrichment media, such as those containing sugar, molasses, and palm sugar (2, 4, and 6% w/v) were tested for S. saprophyticus ICBB 9554. Meanwhile, technical sodium acetate (NaAc), commercial vinegar 25%, and cider vinegar (5, 10, and 15 mM acetate concentration) were tested for C. freundii ICBB 9763. Both the exoelectrogen bacteria were tested for the …

Fish Farming Wastewater Treatment Using Algae-Cyanobacterial Inocula, Yolanys Aranda

Graduate Industrial Research Symposium

Fish is one of the most important nutrient sources of the human diet, and its low-cost aquaculture production is advantageous. During processing, large quantities of organic and inorganic nutrients are produced. Discharging fish farming wastewater to the environment without proper treatment can support harmful algal growth. Therefore, aquaculture effluent must be treated prior to discharge to the receiving waters. In this study, six different cyanobacteria and algae species, including Chlorococcumminutum, Porphyridiumcruentum, Chlorella vulgaris, Microcystis aeruginosa, Chlamydomonas reinhardtii, and Fischerellamuscicola were studiedto treatfish aquaculture wastewater, using mix-culture bacteria as the inoccolum. All samples were incubated for 21 days. Parameters such as …

Susceptibility Of Pre-Adult Biological Stages Of Mythimna Separata (Walker) (Lepidoptera: Noctuidae) To Three Entomopathogenic Fungi (Hypocreales), Melissa P. Montecalvo, Marcela M. Navasero

The Philippine Agricultural Scientist

Armyworms are polyphagous insect pests of agricultural crops. Their population is usually managed below threshold level using insecticides. However, a single control measure is insufficient to attain a sustainable pest management. Hence, this research was conducted to assess the three species of entomopathogenic fungi as potential biological control agents against Mythimna separata (Walker) or paddy armyworm. Dose mortality assays were conducted to determine the pathogenicity of Beauveria bassiana (Bals.) Vuill., Metarhizium anisopliae (Metschn.) Sorokin, and Metarhizium rileyi (Farlow) Kepler, S.A. Rehner and Humber against various biological stages of M. separata including egg, 1^st to 6^th larval instars, prepupa, …

Assessing Functional Biodiversity For The Future Of Plants, Planet, And People, Ali Loker

Doctor of Plant Health Program: Dissertations and Student Research

Biodiversity plays a critical role in supporting life in global ecosystems and its links to ecosystem services and sustainability are recognized by scientific and non-scientific communities. Growing awareness of the importance of biodiversity is accelerated by discussions of its loss, and how to design interventions to conserve and mitigate a biodiversity crisis. Stakeholders are funding and implementing assessment strategies at various scales to help direct conservation efforts. There is also growing interest in measuring and communicating biodiversity outcomes.

Functional biodiversity characterizes the multiplicity of life forms into groups based on their diverse contributions to natural and agro-ecosystems. Assessing functional biodiversity …

The Kinetics Of Biocontaminant Inactivation: A Comparative Study With Bacillus Globigii And Bacillus Anthracis, Leigh M. Durden

Theses and Dissertations

Bacillus anthracis has been a biological threat for decades and after the 2001 terrorist attack via the U.S. Postal Service where five people died, there was heightened awareness and inquiry on the subject (Goel, 2015; Greenberg et al., 2010; Nicholson & Galeano, 2003; Spotts Whitney et al., 2003). The health risk to humans makes this biological agent, a Tier 1 agent and one of the most likely to be used in an attack (Anthrax as a Bioterrorism Weapon | CDC, n.d.; Driks, 2009; Rose & Rice, 2014). B. anthracis is one of most resistant and potent biological warfare agents as …

Evaluation Of Qpcr To Detect Shifts In Population Composition Of The Rhizobial Symbiont Mesorhizobium Japonicum During Serial In Planta Transfers, Kenjiro W. Quides, Yoobeen Lee, Teresa Hur, Hagop S. Atamian

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Microbial symbionts range from mutualistic to commensal to antagonistic. While these roles are distinct in their outcome, they are also fluid in a changing environment. Here, we used the Lotus japonicus–Mesorhizobium japonicum symbiosis to investigate short-term and long-term shifts in population abundance using an effective, fast, and low-cost tracking methodology for M. japonicum. We use quantitative polymerase chain reaction (qPCR) to track previously generated signature-tagged M. japonicum mutants targeting the Tn5 transposon insertion and the flanking gene. We used a highly beneficial wild type and moderately beneficial and non-beneficial mutants of M. japonicum sp. nov. to demonstrate the specificity …

Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder

Cal Poly Humboldt theses and projects

Soil acidity is a common agricultural problem worldwide, as approximately 50% of all potentially arable soils are affected by pH limitations. At soil pH 3+) is considered to be the chemical form of aluminum in acid soil that hinders plant growth the most. Potentially, soil organic matter (SOM) can ameliorate the toxic effects of Al³⁺ on plants and microbes by binding with Al³⁺, thus preventing Al³⁺ (and other species of aluminum) from interacting in the rhizosphere. Increasing SOM also increases soil health indicators (i.e., microbial activity, soil water holding capacity, aggregate stability, porosity, etc.) while the …

Implications Of Intraspecific Variation In Soil Microbes On Solidago Performance, Yazeed Alshammari

Masters Theses

This study explored the implications of intraspecific variation in soil microbes on the performance of Solidago altissima, a North American species that has become invasive across several continents. This research explored how different clones of Solidago altissima were associated with bacterial and fungal soil microbial communities, which influenced plant performance. In a common garden of 24 Solidago altissima clones, I analyzed the relationship between soil microbial communities, foliar chemistry, clone genetic relatedness, and plant performance. My methods included analysis of soil microbial communities (bacterial and fungal), genetic distances among clones to assess relatedness, and measures of plant performance (light …