Microbial Physiology Commons^™

How Acetylation Regulates Metabolic Enzyme Function During Environmental Shifts, Jared Canonigo

Biological Sciences Undergraduate Honors Theses

Organisms such as Saccharomyces cerevisiae can regulate the mechanisms of proteins through post-translational modification. These modifications play a vital role in functional proteomic activity because they can regulate protein activity, localization, and interaction with other cellular molecules. Such modifications include phosphorylation, methylation, and acetylation. The metabolic mechanisms of yeast became of keen interest to our lab because our lab noticed many stress defense proteins were being acetylated during stress heat shock. Notably, Adh1p and Adh2p showed both an increase and a decrease in acetylation at two lysine residues (K315 and K314) overtime during heat shock respectively, though the exact function ...

Increasing Stress Tolerance In Saccharomyces Cerevisiae Using Lipocalin Genes, Ximena Leon

Honors Theses

Saccharomyces cerevisiae is a microorganism that is commonly used in industries, but its productivity is significantly hindered by its inability to resist high stress levels found in industrial processes. By increasing stress tolerance in S. cerevisiae, its role in industrial processes could be maximized. The objective of this study is to determine if complementation of lipocalin genes into the wildtype and knockout strains of S. cerevisiae can increase stress tolerance against a variety of stressors. We identified the knockout yeast strains, ALD3, ALD4, PDX3, and ILV1, as being sensitive to various stressors including salinity, heat, oxidative, and osmotic stresses. Arabidopsis ...

B12: The T Cell Co-Receptor Cd5 Alters Mouse Behavior And Gut Microbiome Composition, Kyle Reaveley

Annual Research Symposium

No abstract provided.

Yeasts Isolated From Traditional Brem Bali Show Stress Tolerance Phenotype Against Fermentation-Related Stresses, Audria Bayu Lenka, Rika Indri Astuti, Sri Listiyowati

Makara Journal of Science

The search for microbes, primarily yeasts with unique characters such as the tolerance against fermentation-related-stresses, is gaining significant interest nowadays. Traditionally made alcoholic beverages can be used as sources for such yeasts, given that during fermentation and storage, microbes may develop stress tolerance responses leading to naturally stress-tolerant yeast strains. In this study, we used an alcoholic beverage, that is, Brem Bali, as the source of potential yeast isolates. We isolated nine yeast isolates from two traditional Brem Bali products. All isolates showed tolerance against high glucose stress (40–50%) and sensitivity against high-temperature stress (37–50 °C). Notably, isolate ...

Mfd Affects Global Transcription And The Physiology Of Stressed Bacillus Subtilis Cells, Holly Anne Martin, Anitha Sundararajan, Tatiana S. Ermi, Robert Heron, Jason Gonzales, Kaiden Lee, Diana Anguiano-Mendez, Faye Schilkey, Mario Pedraza-Reyes, Eduardo A. Robleto

Life Sciences Faculty Publications

© Copyright © 2021 Martin, Sundararajan, Ermi, Heron, Gonzales, Lee, Anguiano-Mendez, Schilkey, Pedraza-Reyes and Robleto. For several decades, Mfd has been studied as the bacterial transcription-coupled repair factor. However, recent observations indicate that this factor influences cell functions beyond DNA repair. Our lab recently described a role for Mfd in disulfide stress that was independent of its function in nucleotide excision repair and base excision repair. Because reports showed that Mfd influenced transcription of single genes, we investigated the global differences in transcription in wild-type and mfd mutant growth-limited cells in the presence and absence of diamide. Surprisingly, we found 1,997 ...

Assessment Of Chlorine Resistance Enterobacter Cloacae Isolated From Water Storage Tanks In Sulaimaniyah City-Iraq, Hastyar H. Najmuldeen

Passer Journal

This study was designed to determine the extent of contamination of water storage tanks by non-lactose fermenter Enterobacter spp, and to characterize the chlorine and antibiotic resistance status. Moreover, to find the correlation between biofilm formation and resistance to chlorine. For this purpose, a total of 60 water samples were collected from residential and restaurant water storage tanks. Bacterial analysis and antibiotic susceptibility profiles of the samples were assessed by the Most Probable Number (MPN) and Vitek 2 compact tests, respectively. The biofilm formation was quantified by crystal violet staining method and chlorine resistance test by microdilution technique.

Obtained results ...

Micro-Physiological Models To Mimic Mucosal Barrier Complexity Of The Human Intestine In Vitro, Abhinav Sharma

Doctoral Dissertations

The mucosal barrier in the intestine is vital to maintain selective absorption of nutrients while protecting internal tissues and maintaining symbiotic relationship with luminal microbiota. This bio-barrier consists of a cellular epithelial barrier and an acellular mucus barrier. Secreted mucus regulates barrier function via in situ biochemical and biophysical interaction with luminal content that continually evolves during digestion and absorption. Increasing evidence suggests that a mucus barrier is indispensable to maintain homeostasis in the gastrointestinal tract. However, the importance of mucus barrier is largely underrated for in vitro mucosal tissue modeling. The major gap is the lack of experimental material ...

Investigating Microbial And Host Factors That Modulate Severity Of Clostridioides Difficile Associated Disease, Armando Lerma

Dissertations, Theses, & Student Research in Food Science and Technology

Clostridioides difficile is recognized as one of the most important pathogens in hospital and community healthcare settings. The clinical outcome of infection of toxigenic C. difficile infection (CDI) ranges from asymptomatic colonization to fulminant pseudomembranous colitis and death. In recent studies, it has been suggested that a high proportion of nosocomial CDI cases are transmitted from asymptomatic carriers which might be acting as infection reservoirs. Understanding what causes the different responses to infection could lead to the development of novel prevention and treatment strategies. Although several explanations have been proposed to explain variations in susceptibility, understanding of the exact mechanisms ...

Metabolic Interactions In Microbial Communities, Elizabeth A. Shank

University of Massachusetts Medical School Publications

The Shank laboratory studies the chemical and physical interactions of microbes with each other and their hosts. Microbes live everywhere, and their activities can have profound impacts on their hosts as well as on ecosystem‐level processes. How microbes interact within these communities, however, remains largely unknown. We are fascinated by the idea that microbes are able to generate and secrete chemical cues (known as specialized or secondary metabolites) that can act as interspecies signals to influence the physiology and metabolism of their microbial neighbors, and thus contribute to the stability and functioning of complex microbial communities. Our research dissects ...

The Physiology And Evolution Of Selenite Respiration In Bacteria, Michael Wells

Electronic Theses and Dissertations

The selenium oxyanions selenate (Se(VI)) and selenite (Se(IV)) can be utilized by some bacteria and archaea as terminal electron acceptors in anaerobic respiration. Se(VI) and Se(IV) respiration is mediated by a phylogenetically and ecologically diverse array of organisms, suggesting that selenium respiration is ubiquitous in natural environments. Several respiratory Se(VI) reductases have been characterized in bacteria, revealing that Se(VI) respiration has evolved independently several times in this domain. Se(IV) respiration, in contrast, has yet to be characterized. I have purified and characterized the first respiratory Se(IV) reductase from Bacillus selenitireducens MLS10. The ...

Linearized Siderophore Products Secreted Via Macab Efflux Pump Protect Salmonella Enterica Serovar Typhimurium From Oxidative Stress, L M. Bogomolnaya, Ronak Tilvawala, J. R. Elfenbein, J. D. Cirillo, H. L. Andrews-Polymenis

Open Access Publications by UMMS Authors

Nontyphoidal salmonellae (NTS) are exposed to reactive oxygen species (ROS) during their residency in the gut. To survive oxidative stress encountered during infection, salmonellae employ several mechanisms. One of these mechanisms involves the multidrug efflux pump MacAB, although the natural substrate of this pump has not been identified. MacAB homologs in pseudomonads secrete products of nonribosomal peptide synthesis (NRPS). In Salmonella enterica serovar Typhimurium, the siderophore enterobactin is produced by NRPS in response to iron starvation and this molecule can be processed into salmochelin and several linear metabolites. We found that Salmonella mutants lacking the key NRPS enzyme EntF are ...

Dietary Soluble And Insoluble Fiber With Or Without Enzymes Altered The Intestinal Microbiota In Weaned Pigs Challenged With Enterotoxigenic E. Coli F18, Qingyun Li, Xiyu Peng, Eric R. Burrough, Orhan Sahin, Stacie A. Gould, Nicholas K. Gabler, Crystal L. Loving, Karin Dorman, John F. Patience

Animal Science Publications

Post-weaning diarrhea caused by enterotoxigenic E. coli (ETEC) causes significant economic losses for pig producers. This study was to test the hypotheses that an ETEC challenge disrupts intestinal microbial homeostasis and the inclusion of dietary soluble (10% sugar beet pulp) or insoluble fiber (15% corn distillers dried grains with solubles) with or without exogenous carbohydrases will protect or restore the gut microbial homeostasis in weaned pigs. Sixty crossbred piglets (6.9 ± 0.1 kg) were blocked by body weight and randomly assigned to one of six treatments (n = 10), including a non-challenged control (NC), ETEC F18-challenged positive control (PC), ETEC-challenged ...

Second Messenger Cyclic-Di-Gmp Regulation In Acinetobacter Baumannii, Justin Deal

Undergraduate Honors Theses

Over time, “superbugs,” or bacteria that have become resistant to antibiotics, have become a great concern in modern medicine. Viable alternates are currently being looked into as effective and safe ways to prevent or treat infections caused by these superbugs. One such method is through the utilization of the second messenger molecule cyclic-di-GMP (c-di-GMP) that has been shown to regulate phenotypes within other bacteria that may control surface colonization in Acinetobacter baumannii. Through a series of experiments, the active enzymes that create c-di-GMP - diguanylate cyclases - and break down c-di- GMP - phosphodiesterases - have been inactivated in mutants to test phenotypes including ...

The Effects Of Farnesol, A Quorum Sensing Molecule From Candida Albicans, On Alcaligenes Faecalis, Savannah Hutson

Undergraduate Honors Theses

Quorum sensing molecules have become a recent focus of study to learn if and how they can be used, both on their own and in conjecture with current antimicrobial methods, as a means of bacterial control. One such quorum sensing molecule is the sesquiterpene alcohol, Farnesol, which is synthesized and released by the fungus, Candida albicans. In most in-vivo cases, our laboratory has shown that Alcaligenes faecalis overtakes C. albicans, preventing its growth. However, as a way to counteract this inhibitory effect, Farnesol may be one way that Candida has found to fight back. In this study, we focused on ...

Effects Of An F18 Enterotoxigenic Escherichia Coli Challenge On Growth Performance, Immunological Status, And Gastrointestinal Structure Of Weaned Pigs And The Potential Protective Effect Of Direct-Fed Microbial Blends, Spenser L. Becker, Qingyun Li, Eric R. Burrough, Danielle Kenne, Orhan Sahin, Stacie A. Gould, John F. Patience

Animal Science Publications

The objective of this experiment was to investigate the impact of an F18 enterotoxigenic Escherichia coli (ETEC) challenge on growth performance, aspects of intestinal function, and selected immune responses of piglets, as well as to evaluate potential protective effects of direct-fed microbial (DFM) blends. Seventy-two weaned piglets (6.4 ± 0.2 kg body weight [BW]; ~21 d of age) were assigned to one of four treatments: 1) NC: Nonchallenged (n = 10), 2) positive challenged control (PC): F18 ETEC-challenged (n = 10), 3) PC + DFM1 (n = 8; three strains of Bacillus amyloliquefaciens; 7.5 × 105 colony-forming units [cfu]/g), or 4) PC ...

Research Tools And Their Uses For Determining The Thermal Inactivation Kinetics Of Salmonella In Low-Moisture Foods, Soon Kiat Lau

Dissertations, Theses, & Student Research in Food Science and Technology

The reputation of low-moisture foods as safe foods has been crumbling over the past decade due to repeated involvement in foodborne illness outbreaks. Although various pasteurization technologies exist, a majority are thermal processes and have not been well-characterized for pasteurizing low-moisture foods. In addition, the nature of a low-moisture food matrix introduces various experimental complications that are not encountered in high-moisture foods. In this dissertation, the development, building instructions, and characterization of various open source tools for studying the inactivation kinetics of microorganisms in low-moisture foods are described. The first tool is the TDT Sandwich, a dry heating device for ...

Cell Cycle Associated Gene Expression Predicts Function In Mycobacteria, Aditya C. Bandekar

GSBS Dissertations and Theses

While the major events in prokaryotic cell cycle progression are likely to be coordinated with transcriptional and metabolic changes, these processes remain poorly characterized. Unlike many rapidly-growing bacteria, DNA replication and cell division are temporally-resolved in mycobacteria, making these slow-growing organisms a potentially useful system to investigate the prokaryotic cell cycle. To determine if cell-cycle dependent gene regulation occurs in mycobacteria, we characterized the temporal changes in the transcriptome of synchronously replicating populations of Mycobacterium tuberculosis (Mtb). By enriching for genes that display a sinusoidal expression pattern, we discover 485 genes that oscillate with a period consistent with the cell ...

Non-Tuberculous Mycobacterial Infections-A Neglected And Emerging Problem, Imran Ahmed, Simon Tiberi, Joveria Farooqi, Kauser Jabeen, Dorothy Yeboah-Manu, Giovanni Battista Migliori, Rumina Hasan

Department of Pathology and Laboratory Medicine

Non-tuberculous mycobacteria (NTM) are ubiquitous dwellers of environmental niches and are an established cause of natural and nosocomial infections. The incidence of NTM infections is rising owing to a growing population of immunocompromised and vulnerable individuals, complex medical and surgical procedures, as well as increased awareness and diagnostic capabilities. The prevalence of different NTM varies between continents, regions, and countries. The true global burden of pulmonary and extrapulmonary disease is unknown and estimates are subject to under and/or over-estimation. Diagnosis requires confirmation by isolation of NTM along with clinical and radiological criteria, which may be suboptimal at all levels ...

Comparison Of Intestinal Permeability, Morphology, And Ileal Microbial Communities Of Commercial Hens Housed In Conventional Cages And Cage-Free Housing Systems, Maddison L. Wiersema, Lucas Koester, Stephan Schmitz-Esser, Dawn A. Koltes

Animal Science Publications

The gastrointestinal health of poultry can be impacted by a variety of factors including their environment. As egg production moves from conventional cage housing (CC) towards cage-free housing (CF), it is important to understand this impact on intestinal health. This study was conducted to determine if housing type impacted intestinal permeability, morphology, and microbial communities in commercial hens across housing systems. Hens were randomly selected from 2 rooms of CC (n = 25) and CF (n = 25) at a commercial facility. Birds were given fluorescein isothiocyanate dextran (FITC-D) by oral gavage to measure intestinal permeability. Jejunal and ileal samples were collected ...

Redirection Of Skn-1 Abates The Negative Metabolic Outcomes Of A Perceived Pathogen Infection, James D. Nhan, Christian D. Turner, Sarah M. Anderson, Chia-An Yen, Hans M. Dalton, Hilary K. Cheesman, Dana L. Ruter, Nandhitha Uma Naresh, Cole M. Haynes, Alexander A. Soukas, Read Pukkila-Worley, Sean P. Curran

Open Access Publications by UMMS Authors

Early host responses toward pathogens are essential for defense against infection. In Caenorhabditis elegans, the transcription factor, SKN-1, regulates cellular defenses during xenobiotic intoxication and bacterial infection. However, constitutive activation of SKN-1 results in pleiotropic outcomes, including a redistribution of somatic lipids to the germline, which impairs health and shortens lifespan. Here, we show that exposing C. elegans to Pseudomonas aeruginosa similarly drives the rapid depletion of somatic, but not germline, lipid stores. Modulating the epigenetic landscape refines SKN-1 activity away from innate immunity targets, which alleviates negative metabolic outcomes. Similarly, exposure to oxidative stress redirects SKN-1 activity away from ...