Other Microbiology Commons^™

Antibiotic-Resistant Bacteria In Freshwater Crayfish, Colby Finch

Honors Theses

The presence of antibiotic-resistant bacteria is increasing in natural aquatic environments. Alongside this, organisms that live in these ecosystems are increasingly harboring antibiotic-resistant bacteria. In this study, I analyzed the capacity for the crayfish species Procambarus vioscai paynei to harbor antibiotic-resistant bacteria. Crayfish, as well as water and sediment, were sampled from a pond at the University of Mississippi Field Station. The guts of crayfish were plated on TSA agar, as well as agar containing vancomycin, erythromycin, penicillin, tetracycline, or ciprofloxacin. Following incubation, counts of bacteria were determined. Selected bacterial isolates were tested for multiple antibiotic-resistance. Bacterial isolates were also …

Identification Of Critical Points For Bacterial Contamination In The Microbrewery Environment, Alex Ryan Thompson

All Theses

There are 8,884 craft breweries producing over 23 million barrels of beer in the United States as of 2020. These 23 million barrels of craft beer account for 12.3% of the United States beer consumption in 2020. The American craft beer industry is substantial and needs to protect its product from bacterial contamination.

Overall, beer is a microbially stable product. Beers pH, ethanol levels, CO₂ concentrations, the presence of hop-derived antimicrobial compounds, and low levels of O₂ make beer a highly unfavorable environment for most bacterial species. Furthermore, the brewing process, which involves heat treatments and chemical sanitizers …

Biodegradation Of Rubber Particles In Soil: Using Acclimated Bacteria Isolated From Kansas Soil To Degrade Cryogrinds In Slurry, Shane Graham

Williams Honors College, Honors Research Projects

This study investigated the viability of bioremediating rubber cryogrind using enriched indigenous bacteria. To begin the experiment, soils from three highway roadside locations in Kansas, KS 96 and West, KS 400 and 143^rd, and 199^th, were collected and transported to the lab to be studied. An initial soil characterization was run on the soil samples using distilled (DI) water mixture and 0.01 M CaCl₂ to assess conductivity. The soils were tested to gather a baseline of the relationship between pH and conductivity and the impact of its distance from the roadside. Bacteria were isolated from …

Isolation Of Caldatribacterium (Op9) And Investigation Of Its Potential Interactions With A Novel, Co-Cultivated Thermodesulfobacterium Species, Toshio Alvarado

Electronic Theses, Projects, and Dissertations

Atribacteria (OP9), candidate phylum with no representatives in pure culture, is found in various anaerobic environments worldwide. “Caldatribacterium”, a lineage within Atribacteria that is predicted to be a strictly anaerobic sugar fermenter based on cultivation-independent genomic analyses, is currently being maintained in lab enrichment cultures with fucose as its sole growth substrate. Metagenomics and 16S rRNA gene tag sequencing indicated that the fucose culture was a co-culture of “Caldatribacterium” and an uncultivated member of the genus Thermodesulfobacterium. Due to failed attempts to isolate “Caldatribacterium” by dilution-to-extinction and plating, it was hypothesized that “Caldatribacterium” is dependent in some way on the …

The Gut Microbiome: Is Fecal Matter Microbial Composition A Proxy For Intestinal Microbial Composition In Studies Of The Microbiome, Enique Reyes

All Master's Theses

As many health phenomena seem to be affected directly and indirectly by the microbiome, gut microbiome research has increased in the last decade. Issues such as allergies, cancer, obesity, and other health complications have been shown to be influenced by the microbiome. Most of gut microbiome research is done by collecting and sequencing the DNA of the microbiome of the fecal matter from model organisms or human subjects. Studies that use this method of sample collection and analysis assume that fecal matter microbiomes are similar to intestinal microbiomes, and that it can be used as a proxy. At present, no …

Aeromonas Hydrophila In Amphibians: Harmless Bystander Or Opportunistic Pathogen, Zachary P. Rivas

Honors Undergraduate Theses

For several decades amphibian populations have been declining. Historically, the bacterium A. hydrophila (Ah) was hypothesized to be the causal factor in amphibian disease and population declines. However, with the discovery of a chytrid fungus, Batrachochytrium dendrobatidis (Bd) in 1998, which was identified on the skin of amphibians during documented mortality events, Ah research became of minor interest as focus shifted to Bd. Recent studies into the immunocompromising abilities of Bd, however, have opened new questions about its relationship with Ah and their combined effects on a host.

In this study, I explore the …

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 …