Biology Commons^™

Mara Repression Of Virulence Gene Hila In Salmonella, Alexandra King, Lauren Daugherty, Lon Chubiz Phd

Undergraduate Research Symposium

Salmonella is a bacteria most commonly known for causing the eponymous food-related illness. Due to their rapid reproduction rate and their ability to be propogated and maintained in a lab setting, they are commonly used in lab studies so that we can better understand how Salmonella causes disease in organisms that are more difficult to study. One area of interest is analyzing how Salmonella controls expression of the mechanisms that actually cause disease, called virulence traits, in response to the environment. In this study, antibiotic stress was used to analyze virulence gene expression. MarA is a gene that regulates ampicillin …

Growth Of Diatom Fistulifera Alcalina In Bacterial Co-Culture And Comparative Mitogenomics Of Fistulifera Species, Erwin David Berthold

FIU Electronic Theses and Dissertations

Diatoms are excellent biological models of growth and intracellular oil generation. The productivity and compounds of diatoms, especially oils, support aquatic food chains and human medical and industrial needs. The qualities that made diatoms prolific producers, specifically diatom physiological features such as growth rates with intracellular lipid storage in alkaline environments, are however poorly understood. Another physiological aspect that remains unexplored is the effects of bacteria on the growth and lipid production of alkaliphilic diatoms. More studies, especially co-cultures, are needed for advances in diatom biology and strain performance for the algal biotechnological field. Besides physiology, diatom genetics using next-generation …

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 …

Investigation Of An Elevational Gradient Reveals Strong Differences Between Bacterial And Eukaryotic Communities Coinhabiting Nepenthes Phytotelmata, Kadeem J. Gilbert, Leonora S. Bittleston, Mark Arcebal K. Naive, Anthony E. Kiszewski, Perry Archival C. Buenavente, David J. Lohman, Naomi E. Pierce

Biology Faculty Publications and Presentations

Elevation is an important determinant of ecological community composition. It integrates several abiotic features and leads to strong, repeatable patterns of community structure, including changes in the abundance and richness of numerous taxa. However, the influence of elevational gradients on microbes is understudied relative to plants and animals. To compare the influence of elevation on multiple taxa simultaneously, we sampled phytotelm communities within a tropical pitcher plant (Nepenthes mindanaoensis) along a gradient from 400 to 1200 m a.s.l. We use a combination of metabarcoding and physical counts to assess diversity and richness of bacteria, micro-eukaryotes, and arthropods, and …

Effects Of A Neonicotinoid Insecticide On The Growth Of Honey Bee Gut Microbes, Macee Mitchell, Daniel Franzese, Taylor Morales, Shane Lucht, Jesse Steele, Jenifer Walke

2020 Symposium Posters

The gut microbiome plays an essential role in the overall health of organisms. However, the presence and abundance of these microbes may be altered by environmental factors, such as exposure to pesticides. The goals of this project were to understand 1) the prevalence of pesticide residues in honey bees in eastern Washington, and 2) the impact of pesticides to the honey bee gut microbiome. Accordingly, we tested bees from 24 hives among six sites across eastern Washington. High-performance liquid chromatography-mass spectrometry (HPLC-MS) was used to detect the presence and concentration of six commonly used agricultural pesticides: Carbaryl, Chlorpyrifos, Coumaphos, Cypermethrin, …

Factors Affecting The Microbiome Of Ixodes Scapularis And Amblyomma Americanum, R. Jory Brinkerhoff, Chris Clark, Kelly Ocasio, David T. Gauthier, Wayne L. Hynes

Biological Sciences Faculty Publications

The microbial community composition of disease vectors can impact pathogen establishment and transmission as well as on vector behavior and fitness. While data on vector microbiota are accumulating quickly, determinants of the variation in disease vector microbial communities are incompletely understood. We explored the microbiome of two human-biting tick species abundant in eastern North America (Amblyomma americanum and Ixodes scapularis) to identify the relative contribution of tick species, tick life stage, tick sex, environmental context and vertical transmission to the richness, diversity, and species composition of the tick microbiome. We sampled 89 adult and nymphal Ixodes scapularis (N …

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, …

Green Infrastructure Design Influences Communities Of Urban Soil Bacteria, Jessica Lee Joyner, Jordan Kerwin, Maha Deeb, George Lozefski, Bharath Prithiviraj, Anna Paitseva, John Mclaughin, Peter M. Groffman, Zhongqi Cheng, Theodore R. Muth

Publications and Research

The importance of natural ecosystem processes is often overlooked in urban areas. Green Infrastructure (GI) features have been constructed in urban areas as elements to capture and treat excess urban runoff while providing a range of ancillary benefits, e.g., ecosystem processes mediated by microorganisms that improve air and water quality, in addition to the associations with plant and tree rhizospheres. The objective of this study was to characterize the bacterial community and diversity in engineered soils (Technosols) of five types of GI in New York City; vegetated swales, right of way bioswales (ROWB; including street-side infiltration systems and enhanced tree …

The Effects Of A Bacterial Endotoxin On Behavior And Sensory-Cns-Motor Circuits In Drosophila Melanogaster, Oscar Istas, Abigail Greenhalgh, Robin L. Cooper

Biology Faculty Publications

The effect of bacterial sepsis on animal behavior and physiology is complex due to direct and indirect actions. The most common form of bacterial sepsis in humans is from gram-negative bacterial strains. The endotoxin (lipopolysaccharide, LPS) and/or associated peptidoglycans from the bacteria are the key agents to induce an immune response, which then produces a cascade of immunological consequences. However, there are direct actions of LPS and associated peptidoglycans on cells which are commonly overlooked. This study showed behavioral and neural changes in larval Drosophila fed commercially obtained LPS from Serratia marcescens. Locomotor behavior was not altered, but feeding …

Diverse Microbial Communities Hosted By The Model Carnivorous Pitcher Plant Sarracenia Purpurea: Analysis Of Both Bacterial And Eukaryotic Composition Across Distinct Host Plant Populations, Jacob J. Grothjan, Erica B. Young

Biological Sciences Faculty Articles

Background. The pitcher plant Sarracenia purpurea supplements nutrient acquisition through carnivory, capturing insect prey which are digested by a food web community of eukaryotes and bacteria. While the food web invertebrates are well studied, and some recent studies have characterized bacteria, detailed genetic analysis of eukaryotic diversity is lacking. This study aimed to compare eukaryotic and bacterial composition and diversity of pitcher communities within and between populations of host plants in nearby but distinct wetland habitats, and to characterize microbial functions across populations and in comparison with another freshwater community.

Methods. Pitcher fluid was sampled from the two …

Better Living Through Chemistry: Addressing Emerging Antibiotic Resistance, Nathan P. Coussens, Ashley L. Molinaro, Kayla J. Culbertson, Tyler Peryea, Gergely Zahoránszky-Köhalmi, Matthew D. Hall, Dayle A. Daines

Biological Sciences Faculty Publications

The increasing emergence of multidrug-resistant bacteria is recognized as a major threat to human health worldwide. While the use of small molecule antibiotics has enabled many modern medical advances, it has also facilitated the development of resistant organisms. This minireview provides an overview of current small molecule drugs approved by the US Food and Drug Administration (FDA) for use in humans, the unintended consequences of antibiotic use, and the mechanisms that underlie the development of drug resistance. Promising new approaches and strategies to counter antibiotic-resistant bacteria with small molecules are highlighted. However, continued public investment in this area is critical …

Best Practices For Healthy Beaches And Watersheds In Maine: Potential Bioremediation Strategies For Improving Water Quality, Elyse Defranco

Maine Sea Grant Publications

Maine’s watersheds face many challenges from human inputs, with pollution threatening the health of our beaches, rivers, and aquaculture operations. Maine’s rural communities often lack the resources to update aging sewer infrastructure or to adequately maintain septic systems, and these sources of pollution impact watershed health. In addition to addressing sources of pollution, which can be difficult to ascertain and challenging to address when located, bioremediation practices have the potential to aid in clean-up efforts. New technological advances and research discoveries in creative forms of bioremediation are being developed and are producing promising case studies around the world. These new …

A Study On The Dissolution Of Autunite Minerals By Facultative Bacteria In Bicarbonate Media, Sandra C. Herrera Landaez

FIU Electronic Theses and Dissertations

Uranium (U) is a key contaminant at the Hanford site. The formation of uranyl-phosphate bearing minerals such as autunite as a result of tripoliphosphate injections has been used as a U immobilization strategy. Bacteria are known as key factors governing the fate and transport of soil contaminants. This research evaluated the interaction of facultative bacteria Shewanella Oneidensis MR-1 with autunite mineral in bicarbonate-amended media solutions. The concentration of several elements such as U, calcium (Ca) and phosphorous (P) released as a result of autunite mineral biodissolution were determined as a function of time; changes in cell density and protein assay …

An Analysis Of Bacterial Contamination Of Chicken Eggs And Antimicrobial Resistance, Holly Spitzer

All College Thesis Program, 2016-2019

Chicken eggs are a major component of American diets, with an average yearly consumption of approximately 250 eggs per person (American Humane Society). While highly nutritious, eggs are also one of the leading causes of food poisoning and food borne illness in the United States. Eggs may become contaminated by a number of different types of bacteria during production, including Salmonella, a group of bacteria that, according to the CDC, causes more than 1.2 million cases of food borne illness in the United States every year. In an effort to decrease the frequency of bacterial contamination, many food producers …

Isolation And Characterization Of Microbial Community Associated With Diadumene Lineata, The Orange-Striped Sea Anemone, Tiffany Lin, Andrew Weir

Student and Faculty Research Days

The orange-striped sea anemone, Diadumene lineata, is a marine invertebrate that can be found in the Northern Hemisphere. Distribution of Diadumene lineata ranges from Japan to the Gulf of Argentina. This invasive anemone originated from the Pacific Coast of Asia and serves as a host for a diverse microbial community including a photosynthetic alga. The epiphytic bacteria adhere to the outer surface as well as to the gastrovascular cavity of the host. The microbial community associated with Diadumene lineata is relatively unknown. This study attempted to isolate and identify bacteria commonly associated with this invasive marine invertebrate. Diadumene lineata was …

Is There Specificity In A Defensive Mutualism Against Soil Versus Lab Nematodes, Dictyostelium Discoideum Farmers And Their Bacteria?, Boahemaa Adu-Oppong,, David C. Queller, Joan E. Strassmann

Biology Faculty Publications & Presentations

Background: The social amoeba Dictyostelium discoideum is a soil-dwelling microbe, which lives most of its life cycle in the vegetative stage as a predator of bacteria and as prey for nematodes. When bacteria are sparse, amoebae aggregate into a multicellular fruiting body. Some clones of D. discoideum have agriculture (Brock et al., 2011). They carry bacteria through the social stage, eat them prudently, and use some bacteria as defence against non-farming D. discoideum competitors. Caenorhabditis elegans preys on D. discoideum in the laboratory but does not encounter it in nature because C. elegans lives on rotten fruit. The nematode …

Characterization Of A Putative Cephalotoxin From The Hemocytes Of Euprymna Scolopes, Jessie E. Scott

University Scholar Projects

Many organisms have beneficial microbial symbionts, and complex interactions between the immune system and the bacteria must occur to allow these symbioses to persist. The host immune system must recognize and preferentially tolerate the beneficial microorganisms, while simultaneously eliminating harmful pathogens. The Hawaiian bobtail squid, Euprymna scolopes, is a model organism for host-microbe interactions because of the unique light organ symbiosis. Hemocytes, the squid’s primary immune cell, infiltrate and patrol the light organ and continuously interact with the symbiont Vibrio fischeri. Using this model, several innate immunity genes have been shown to be differentially expressed in the hemocytes …

Effect Of Prey Richness On A Consumer’S Intrinsic Growth Rate, Brian J. Darby, Michael A. Herman

School of Biological Sciences: Faculty Publications

The intrinsic growth rate of nonselective microbivores increases asymptotically with increasing prey biomass, but we do not know how intrinsic growth rate is affected by prey richness. The objective of this experiment was to determine the effect of prey richness on the growth kinetics of nematode predators while grazing on mixed bacterial lawns. We found that the intrinsic growth rate of Caenorhabditis elegans in laboratory culture increased asymptotically with prey richness. The mechanism of this pattern was primarily due to the best available prey species in the mixture: the intrinsic growth rate of the consumer feeding on a mixture of …

Effects Of Sugar-Amendment On Bacterial & Fungal Abundance In Native Vs. Nonnative-Dominated Soils Of A Puget Lowland Prairie, Jessica Wong

Summer Research

Scotch broom is a nonnative plant that has invaded the plant communities of the Pacific Northwest in the United States. It associates with bacteria in the soil to fix nitrogen from the atmosphere, thereby elevating soil nitrogen levels and encouraging the invasion of the community by other nonnative plants like itself. Researchers have used sugar-amendment to decrease soil nitrogen and restore native plant growth. Our study took place in Glacial Heritage Preserve, a Puget lowland prairie that has been invaded by broom in several areas. We aimed to investigate whether sugar-amendment increased or decreased bacterial and fungal abundance in native …

A Multidisciplinary Approach To Food Safety Evaluation: Hummus Spoilage And Microbial Analysis Of Kitchen Surfaces In Residential Child Care Institutions (Rcci) In Massachusetts, U.S.A., Elsina E. Hagan

Masters Theses 1911 - February 2014

Food borne illnesses continues to be a public health challenge in the United States (U.S.); an estimated 9.4 million incident cases occurred in 2011. In view of this challenge we conducted two food safety studies; 1) related to product formulation (hummus spoilage challenge study) and 2) evaluating the microbial safety of domestic kitchen surfaces in Residential Child Care Institutions (RCCI pilot study).

Hummus is of Mediterranean origin but is currently eaten globally. This challenge study evaluates a variety of industrial hummus formulations (four in total, differing in pH and/or addition of a preservative (natamycin). Two batches were setup: batch 1; …

Environmental Controls On The Landscape-Scale Biogeography Of Stream Bacterial Communities, Noah Fierer, Jennifer L. Morse, Sean T. Berthrong, Emily S. Bernhardt, Robert B. Jackson

Scholarship and Professional Work - LAS

We determined the biogeographical distributions of stream bacteria and the biogeochemical factors that best explained heterogeneity for 23 locations within the Hubbard Brook watershed, a 3000-ha forested watershed in New Hampshire, USA. Our goal was to assess the factor, or set of factors, responsible for generating the biogeographical patterns exhibited by microorganisms at the landscape scale. We used DNA fingerprinting to characterize bacteria inhabiting fine benthic organic matter (FBOM) because of their important influence on stream nutrient dynamics. Across the watershed, streams of similar pH had similar FBOM bacterial communities. Streamwater pH was the single variable most strongly correlated with …

Communities Of Cloacal Bacteria In Tree Swallow Families, Michael P. Lombardo, Patrick A. Thorpe, R. Cichewicz, M. Henshaw, C. Millard, C. Steen, T. K. Zeller

Peer Reviewed Publications

Our aim in this study was to survey the communities of bacteria found in the cloacae of adult and nestling Tree Swallows (Tachycineta bicolor), determine if there were familial patterns of prevalence, and determine if there were relationships between bacteria loads and nestling size when 12 days old and fledging success.