Environmental Microbiology and Microbial Ecology Commons^™

Surveillance Of A Novel Vesivirus Discovered In An Urban Mephitis Mephitis Population, Amanda E. Diggins

Honors Theses and Capstones

Caliciviridae is a family of non-enveloped, positive-sense, single stranded RNA viruses, including eleven defined genera that contain important pathogens of humans and animals. Within the Caliciviridae family, the genus Vesiviridae includes feline calicivirus, a leading cause of upper respiratory disease in cats, and vesicular exanthema of swine virus, a historical disease of domestic swine that has now been implicated in several marine mammal vesicular diseases, one of which has been confirmed zoonotic. Urban landscapes create a unique environment for rapid intra- and interspecies transmission of viruses. Clustered resources attract high-density populations of synanthropic wildlife species, increasing spatial overlap and heightening …

Investigating Microbe-Mediated Temperature Tolerance In Lemna Minor, Matthew Thomas Farbaniec

Honors Theses and Capstones

Temperature limits plant growth and survival more than many other environmental variables, and increases in the frequency of extreme hot or cold weather events pose significant challenges for plant growth and crop yields. Previous studies have shown that bacteria, fungi, and other microorganisms associated with plants ( i.e., the plant microbiome) can influence host response to temperature stress. These same microbes have their own temperature tolerances. We investigated whether microbial temperature tolerance correlates with plant resilience using an aquatic plant model, Lemna minor, and isolates derived from its microbiome. Microbial isolates were assessed at −10°C, 4°C, and 32°C for …

The Impact Of Nutrient Depletion On The Effect Of Hhq On Emiliania Huxleyi, Marley Gonsalves

Honors Theses and Capstones

Emiliania huxleyi is a ecologically important, bloom-forming coccolithophore. HHQ is a bacteria compound that causes cell stasis in E. huxleyi that can lead to bloom termination. This study analyzed the role that nutrient depletion plays in this relationship. Results show that nitrogen depletion protects cells from the effects of HHQ, affecting bloom dynamics.

Identification Of Novel Biosynthetic Gene Clusters Encoding For Polyketide/Nrps-Producing Chemotherapeutic Compounds From Marine-Derived Streptomyces Hygroscopicus From A Marine Sanctuary, Hannah Ruth Flaherty

Honors Theses and Capstones

Nearly one out of six deaths in 2020, around ten million people, were caused by cancer, making it a leading cause of death worldwide (WHO, 2022). This major public health issue, in addition to the rise of multidrug-resistant (MDR) pathogens, provides a high demand for the discovery of new pharmaceutical drugs to be used clinically to treat these conditions. The Streptomyces genus accounts to produce 39% of all microbial metabolites currently approved for human health, indicating its potential as an important species to study for antimicrobial and anticancer agents. The long linear genome of Streptomyces contains specialized sequences known as …

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 …

Isolation And Identification Of Bacterial Endosymbionts In The Brooding Brittle Star Amphipholis Squamata, Abbey Rose Tedford

Honors Theses and Capstones

Symbiotic associations with subcuticular bacteria (SCB) have been identified and studied in numerous echinoderms, including the SCB of the brooding brittle star, Amphipholis squamata. These SCB, however, have not been studied using current next generation sequencing technologies. Previous studies on the SCB of A. squamata placed these bacteria in the genus Vibrio (γ-Proteobacteria), but subsequent studies suggested that the SCB are primarily composed of α-Proteobacteria. The present study examines the taxonomic composition of SCB associated with A. squamata from the Northwest Atlantic. DNA was extracted using a CTAB protocol and 16S rRNA sequences were amplified …

Attached Algae As An Indicator Of Water Quality: A Study Of The Viability Of Genomic Taxonomic Methods, Allison R. Wood

Honors Theses and Capstones

This research involved evaluating algae as an indicator of water quality in New Hampshire's rivers, with a focus on the Great Bay Estuary. The project had three main goals. First, determining whether or not algae would work as an indicator of water quality in the great bay ecosystem, an environment where tidal currents are strong and water composition is mixed. The second goal was to compare traditional microscopic methods of taxonomy with emerging genomic methods, increasing the economic viability of attached algae monitoring. The third project goal, still underway, is to evaluate massive amounts of genomic data from the Great …

Investigating The Interactions Between Cyanobacteria And Vibrio Parahaemolyticus, Caroline E. Ward

Honors Theses and Capstones

One well-known pathogen that has been the topic of many recent studies is Vibrio parahaemolyticus, which causes thousands of foodborne illnesses a year, mostly from the ingestion of raw or undercooked oysters. It has been shown cyanobacteria can act as a long-term reservoir of Vibrio cholerae, another pathogenic Vibrio, by encasing the cells within mucilaginous sheaths during which Vibrios enter a viable but non-culturable state. In this study we investigated the interaction of V. parahaemolyticus with cyanobacteria to determine whether cyanobacteria aid in the longevity and survival of V. parahaemolyticus. We found that non-pathogenic V. parahaemolyticus …

The Pleiotropic Effects Of Beneficial Mutations Of Adapted Escherichia Coli Populations, Brian Scott Van Dam

Honors Theses and Capstones

Mutations that improve fitness in one environment can often be beneficial, deleterious, or neutral in alternative environments. When a single mutation effects fitness in multiple environments, it is said to be a pleiotropic, which can have important consequences for niche specialization, niche expansion, speciation, and even extinction in the face of environmental change. While previous studies have revealed that pleiotropy is nearly universal, the role of adaptive history in the spectrum of pleiotropic effects has yet to undergo detailed experimental observation. Using experimental evolution we gathered beneficial mutations in a previously adapted strain of Escherichia coli growing in the same …

The Distribution Of Fitness Effects Of Spontaneous Mutations In Vibrio Fischeri, Chelsea K. Jones

Honors Theses and Capstones

Mutations are the ultimate source of the biological diversity on which natural selection acts, but the vast majority of these mutations are harmful. As such, mutations lead to disease states like cancer, extinction of small populations, and can drive pathogen evolution. Unfortunately, because mutations are rare and past studies have been subject to detection biases, very little is known about the distribution of fitness effects from naturally occurring mutations. In this study, we used mutation accumulation and full genome sequencing to capture naturally occurring mutations before they were exposed to the sieve of natural selection in Vibrio fischeri. We …

One Can’T Stand On Its Own: Are Non-Luminescence Traits Necessary For V. Fischeri Colonization Of E. Scolopes?, Feier Liu

Honors Theses and Capstones

Vibrio fischeri and Euprymna scolopes squid establish mutualistic symbiosis and select for each other in the natural environment. V. fischeri provides bioluminescent camouflage for E. scolopes while E. scolopes provides nutrients for V. fischeri. The most intriguing aspect of this relationship is that E. scolopes is highly selective and only allows sustained colonization by luminous, but not dark V. fischeri. Luminescence is the key symbiosis trait; however, other bacterial factors may also allow squid recognition. We hypothesized that there are luminescence linked traits that contribute to colonization. V. fischeri with luminescence variation was isolated and tested for oxidative resistance, …

Soil Bacterial Communities Of A Calcium-Supplemented And A Reference Watershed At The Hubbard Brook Experimental Forest (Hbef), New Hampshire, Usa, Ganapathi Sridevi, Rakesh Minocha, Swathi A. Turlapati, Katherine C. Goldfarb, Eoin L. Brodie, Louis S. Tisa, Subhash C. Minocha

New Hampshire Agricultural Experiment Station Publications

Soil Ca depletion because of acidic deposition-related soil chemistry changes has led to the decline of forest productivity and carbon sequestration in the northeastern USA. In 1999, acidic watershed (WS) 1 at the Hubbard Brook Experimental Forest (HBEF), NH, USA was amended with Ca silicate to restore soil Ca pools. In 2006, soil samples were collected from the Ca-amended (WS1) and reference watershed (WS3) for comparison of bacterial community composition between the two watersheds. The sites were about 125 m apart and were known to have similar stream chemistry and tree populations before Ca amendment. Ca-amended soil had higher Ca …

Bioavailability And Trophic Transfer Of Humic-Bound Copper From Bacteria To Zooplankton, Emile M. Lores, Jonathan Pennock

School of Marine Science and Ocean Engineering

ABSTRACT:

The effect of humic acid (HA) on uptake and transfer of Cu by selected marine organisms from the microbial loop was determined. Bacteria grown with and without 15 µg Cu l^-1 and with and without 10 mg Suwannee River Humic Acid (SRHA) l^-1 were fed to Uronema sp. The Uronema were subsequently fed to Acartia tonsa to determine the effect of humic acid on the uptake and transfer of Cu from bacteria to copepods. The presence of 10 mg SRHA l^-1 reduced Cu uptake in A. tonsa by an average of 54% and significantly reduced the …