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Full-Text Articles in Life Sciences
A Novel Subcluster Of Closely Related Bacillus Phages With Distinct Tail Fiber/Lysin Gene Combinations, Rachel E. Loney, Veronique A. Delesalle, Brianne E. Chaudhry, Megan Czerpak, Alexandra A. Guffey, Leo Goubet-Mccall, Michael Mccarty, Madison S. Strine, Natalie T. Tanke, Albert C. Vill, Gregory P. Krukonis
A Novel Subcluster Of Closely Related Bacillus Phages With Distinct Tail Fiber/Lysin Gene Combinations, Rachel E. Loney, Veronique A. Delesalle, Brianne E. Chaudhry, Megan Czerpak, Alexandra A. Guffey, Leo Goubet-Mccall, Michael Mccarty, Madison S. Strine, Natalie T. Tanke, Albert C. Vill, Gregory P. Krukonis
Biology Faculty Publications
Bacteriophages (phages) are the most numerous entities on Earth, but we have only scratched the surface of describing phage diversity. We isolated seven Bacillus subtilis phages from desert soil in the southwest United States and then sequenced and characterized their genomes. Comparative analyses revealed high nucleotide and amino acid similarity between these seven phages, which constitute a novel subcluster. Interestingly, the tail fiber and lysin genes of these phages seem to come from different origins and carry out slightly different functions. These genes were likely acquired by this subcluster of phages via horizontal gene transfer. In conjunction with host range …
Probiotic Compounds Inhibit Staphylococcus Aureus Biofilm Formation, Reduce Virulence, & Improve Antibiotic Sensitivity, Kyle R. Leistikow
Probiotic Compounds Inhibit Staphylococcus Aureus Biofilm Formation, Reduce Virulence, & Improve Antibiotic Sensitivity, Kyle R. Leistikow
Dissertations (1934 -)
Multidrug-resistant (MDR) bacterial infections are a top five global public health threat, causing 2.8 million infections and 35,000 deaths annually in the US alone. Staphylococcus aureus is one of the most clinically important MDR pathogens in the world with infections leading to high rates of morbidity and mortality in both humans and animals. This bacterium's ability to form protective biofilms further complicates classical antibiotic interventions, highlighting the need for new therapeutics with novel mechanisms of action. The goal of this dissertation was to investigate antibiofilm mechanisms employed by probiotic bacteria to reduce S. aureus virulence and mitigate antimicrobial resistance evolution …
To Be Or Not To Be: A Tale Of Staphylococcal Gpsb, Lauren R. Hammond
To Be Or Not To Be: A Tale Of Staphylococcal Gpsb, Lauren R. Hammond
USF Tampa Graduate Theses and Dissertations
There are two big drivers motivating studies into bacterial cell division. The first is a desire to understand life around us. One of the defining characteristics of life is the ability for a cell to grow and divide, and without in-depth knowledge of this process, we cannot truly understand the complexities that allow for life on this planet. The second motivator is to identify new drug targets in the ongoing fight against antimicrobial resistance. Many infectious organisms have become resistant to commonly used antibiotics, and the bacterial cell division machinery is a largely untapped essential process with many potential therapeutic …
Forty Years Without Family: Three Novel Bacteriophages With High Similarity To Spp1 Reveal Decades Of Evolutionary Stasis Since The Isolation Of Their Famous Relative, Veronique A. Delesalle, Brianne E. Tomko, Albert C. Vill, Katherine B. Lichty, Gregory P. Krukonis
Forty Years Without Family: Three Novel Bacteriophages With High Similarity To Spp1 Reveal Decades Of Evolutionary Stasis Since The Isolation Of Their Famous Relative, Veronique A. Delesalle, Brianne E. Tomko, Albert C. Vill, Katherine B. Lichty, Gregory P. Krukonis
Biology Faculty Publications
SPP1, an extensively studied bacteriophage of the Gram-positive Bacillus subtilis, is a model system for the study of phage–host interactions. Despite progress in the isolation and characterization of Bacillus phages, no previously fully sequenced phages have shared more than passing genetic similarity to SPP1. Here, we describe three virulent phages very similar to SPP1; SPP1 has greater than 80% nucleotide sequence identity and shares more that 85% of its protein coding genes with these phages. This is remarkable, given more than 40 years between the isolation of SPP1 and these phages. All three phages have somewhat larger genomes and more …
Sorption Of Cellulases In Biofilm Enhances Cellulose Degradation By Bacillus Subtilis, Yijie Deng, Shiao Y. Wang
Sorption Of Cellulases In Biofilm Enhances Cellulose Degradation By Bacillus Subtilis, Yijie Deng, Shiao Y. Wang
Faculty Publications
Biofilm commonly forms on the surfaces of cellulosic biomass but its roles in cellulose degradation remain largely unexplored. We used Bacillus subtilis to study possible mechanisms and the contributions of two major biofilm components, extracellular polysaccharides (EPS) and TasA protein, to submerged biofilm formation on cellulose and its degradation. We found that biofilm produced by B. subtilis is able to absorb exogenous cellulase added to the culture medium and also retain self-produced cellulase within the biofilm matrix. The bacteria that produced more biofilm degraded more cellulose compared to strains that produced less biofilm. Knockout strains that lacked both EPS and …
Identification Of The Role Of Swra In Copper Induced Poly-Gamma-Glutamic Acid Production In Bacillus Subtilis, Maya Addison
Identification Of The Role Of Swra In Copper Induced Poly-Gamma-Glutamic Acid Production In Bacillus Subtilis, Maya Addison
Scripps Senior Theses
Each year over 2.8 million Americans are infected by an antibiotic resistant strain of bacteria with over 35, 000 dying as a result (CDC). The lack of development of new antibiotics has renewed interest in the antimicrobial properties of copper. Gram positive bacterium such as Bacillus subtilis produce poly-gamma-glutamic acid (γ-PGA) to sequester excess copper ions. swrA has shown to be essential for proper activation of the pgs operon by phosphorylated DegU via an unknown mechanism. This study seeks to determine the role of swrA in copper induced gamma-PGA production and if swrA and ppsB are involved in copper resistance. …
The Influence Of G4 Dna Structures On Stationary Phase Mutagenesis In Bacillus Subtilis, Tatiana Ermi
The Influence Of G4 Dna Structures On Stationary Phase Mutagenesis In Bacillus Subtilis, Tatiana Ermi
UNLV Theses, Dissertations, Professional Papers, and Capstones
Until the late 1980’s it was widely understood that bacterial variance emerges randomly during growth. Research that followed has convincingly shown evidence for mutations arising in non-growing conditions, a phenomenon known as stationary-phase mutagenesis. In Bacillus subtilis, an elegant mutagenic mechanism has been elucidated in non-growing cells that biases mutations to transcribed regions of a subpopulation. One interesting possibility is that mutations can be further biased to hotspots within genes through alternate DNA structures known as non-B DNA. Non-B DNA have been linked to genomic instability and disease in humans, lesser is known about its role in bacteria. Here we …
To Mid-Cell And Beyond: Characterizing The Roles Of Gpsb And Ypsa In Cell Division Regulation In Gram-Positive Bacteria, Robert S. Brzozowski
To Mid-Cell And Beyond: Characterizing The Roles Of Gpsb And Ypsa In Cell Division Regulation In Gram-Positive Bacteria, Robert S. Brzozowski
USF Tampa Graduate Theses and Dissertations
The bacterial cell division protein FtsZ is a tubulin homolog that forms a ring-like structure at the site of cell division in most bacterial species. There it acts as a scaffold, aiding in the recruitment of other divisome proteins to the site of cell division. Furthermore, studies focusing on the role of FtsZ treadmilling and septal peptidoglycan synthesis implicates that FtsZ plays a direct role in the ultimate closure of the division septum. Thus, many studies in the field of bacterial cell division have focused on FtsZ in terms of its spatial and temporal regulation as well as its ability …
Beneficial Endophytic Bacterial Populations Associated With Medicinal Plant Thymus Vulgaris Alleviate Salt Stress And Confer Resistance To Fusarium Oxysporum, Osama Aballa Abdelshafy Mohamad, Jin-Bao Ma, Yong-Hong Liu, Daoyuan Zhang, Shao Hua, Shirkant Bhute, Brian P. Hedlund, Wen-Jun Li, Li Li
Beneficial Endophytic Bacterial Populations Associated With Medicinal Plant Thymus Vulgaris Alleviate Salt Stress And Confer Resistance To Fusarium Oxysporum, Osama Aballa Abdelshafy Mohamad, Jin-Bao Ma, Yong-Hong Liu, Daoyuan Zhang, Shao Hua, Shirkant Bhute, Brian P. Hedlund, Wen-Jun Li, Li Li
Life Sciences Faculty Research
As a result of climate change, salinity has become a major abiotic stress that reduces plant growth and crop productivity worldwide. A variety of endophytic bacteria alleviate salt stress; however, their ecology and biotechnological potential has not been fully realized. To address this gap, a collection of 117 endophytic bacteria were isolated from wild populations of the herb Thymus vulgaris in Sheikh Zuweid and Rafah of North Sinai Province, Egypt, and identified based on their 16S rRNA gene sequences. The endophytes were highly diverse, including 17 genera and 30 species. The number of bacterial species obtained from root tissues was …
A Natural Antimicrobial From Bacillus Subtilis As A Biosanitizer For Resilient Membrane Biofilms, Pratishtha Verma
A Natural Antimicrobial From Bacillus Subtilis As A Biosanitizer For Resilient Membrane Biofilms, Pratishtha Verma
Electronic Theses and Dissertations
The microbial attachment and colonization on separation membranes lead to biofilm formation. Some selective isolates within the biofilm constitutive microflora acquire resistance and emerge predominant over prolonged use of the membrane. Thus, proving the cleaning and sanitization protocols to be ineffective in adequately removing resilient biofilms. This subsequently leads to selecting microbial resistance within the constitutive microflora to almost all antimicrobial treatments and hence, creates a need to develop novel alternative strategies to control biofilm formation on membrane surfaces. The first research project under this study was designed to understand the microbial interactions and emergence of predominance within biofilm constitutive …
Yfmk Is A Novel Nε-Lysine Acetyltransferase That Directly Acetylates The Histone-Like Protein Hbsu In Bacillus Subtilis, Valerie J. Carabetta, Todd M. Greco, Ileana M. Cristea, David Dubnau
Yfmk Is A Novel Nε-Lysine Acetyltransferase That Directly Acetylates The Histone-Like Protein Hbsu In Bacillus Subtilis, Valerie J. Carabetta, Todd M. Greco, Ileana M. Cristea, David Dubnau
Rowan-Virtua Research Day
Recently, Ne-lysine acetylation was realized to be a prevalent bacterial post-translational modification (PTM), contrary to the historical notion that this was a rare occurrence. Acetylation can impact protein function in multiple ways, by modifying conformation, interactions, subcellular localization or activity. In bacteria, hundreds of proteins are known to be acetylated, including those involved essential processes such as DNA replication, nucleoid organization, translation, cell shape, central carbon metabolism, and even several virulence factors. Despite the growing recognition that numerous proteins are acetylated, the biological significance of the vast majority of these modifications in any bacteria remains largely unknown. Previously, …
Development Of The K-State (Competence) And Mutagenesis In Stressed Bacillus Subtillis Cells, Amanda Kidman
Development Of The K-State (Competence) And Mutagenesis In Stressed Bacillus Subtillis Cells, Amanda Kidman
UNLV Theses, Dissertations, Professional Papers, and Capstones
Mutagenesis is central to the evolutionary process. We currently view evolution as a gradual process affecting all cells within a population. However, my project studied an underestimated part of the evolutionary process: mutations generated during stationary phase (caused by nutritional stress or growth arrest) within a subpopulation of cells. I used Bacillus subtilis, a bacterial model for cell growth and differentiation. Stationary-phase cultures of B. subtilis differentiate subpopulations that exhibit different survival strategies including competence, secondary metabolite production, biofilm formation, cannibalism, and endospore formation. The development of competence permits cells to uptake exogenous DNA and incorporate it into their genome. …
Genetic And Biochemical Analysis Of The Micrococcin Biosynthetic Pathway, Philip Ross Bennallack
Genetic And Biochemical Analysis Of The Micrococcin Biosynthetic Pathway, Philip Ross Bennallack
Theses and Dissertations
Declining antibiotic discovery and flourishing antibiotic resistance have led to a modern antibiotic crisis which threatens to compromise our ability to treat infectious disease. Consequently, there is significant interest in developing new antibiotics with novel modes of action and chemical properties. Ribosomally synthesized and post-translationally modified peptides (RiPPs) are natural compounds with the appealing attributes of being derived directly from a genetic template while possessing numerous exotic chemical features that contribute to stability and antimicrobial activity. Abundant in nature, their diverse range of biological activities makes them excellent prospects for antibiotic development. Thiopeptides, a RiPP family rich in chemical complexity, …
The Role Of Mfd In Stationary-Phase Oxidative Damage Repair In Bacillus Subtilis, Katelyn E. Porter
The Role Of Mfd In Stationary-Phase Oxidative Damage Repair In Bacillus Subtilis, Katelyn E. Porter
UNLV Theses, Dissertations, Professional Papers, and Capstones
Since the 1950’s it has been shown that bacterial cells accumulate mutations even in non- dividing conditions, but how this type of mutation occurs is still highly debated. In Bacillus subtilis, Mfd, a precursor of the nucleotide excision repair (NER) system, mediates the formation of mutations in stationary-phase or non-replicating cells. In growing cells, Mfd recruits repair when RNA polymerase is stalled during transcription; it then recruits proteins from NER to repair damage. Here, we examine the hypothesis that Mfd mediates the formation of mutations by interacting with cellular components that repair reactive oxygen species (ROS), a natural byproduct of …
Investigation Of Bacillus Subtilis As A Biopesticide Against Botrytis Cinerea, Kenneth K. Ng
Investigation Of Bacillus Subtilis As A Biopesticide Against Botrytis Cinerea, Kenneth K. Ng
Master's Theses
The objective of this thesis was to investigate BiOWiSHTM-Aqua, a commercial dry solid formulation containing a consortium of bacteria and yeast, as a biopesticide for treatment of Botrytis cinerea, a gray mold that affects strawberries. BiOWiSHTM-Aqua was compared with another commercial product specifically used as a fungicide and bacteriocide, Serenade® Garden Disease Control Spray (concentrated Bacillus subtilis strain QST 713). Both laboratory tests as well as in vivo lab tests were conducted. BiOWiSHTM-Aqua results varied widely from plate to plate, regardless of experimental conditions. In some of these plates, inhibition zones were observed …
Bacteriocin Formation By Dominant Aerobic Sporeformers Isolated From Traditional Maari, Donatien Kabore, Line Thorsen, Dennis Sandris Nielsen, Torben Sune Berner, Hagrétou Sawadogo-Lingani, Bréhima Diawara, Mamoudou H. Dicko Prof., Mogens Jackobsen
Bacteriocin Formation By Dominant Aerobic Sporeformers Isolated From Traditional Maari, Donatien Kabore, Line Thorsen, Dennis Sandris Nielsen, Torben Sune Berner, Hagrétou Sawadogo-Lingani, Bréhima Diawara, Mamoudou H. Dicko Prof., Mogens Jackobsen
Pr. Mamoudou H. DICKO, PhD
The antimicrobial activity of 8 Bacillus spp. and 2 Lysinibacillus spp. representing the predominant aerobic sporeformers during traditional maari fermentations, a traditional fermented baobab seeds product fromBurkina Faso,was investigated. The antimicrobial activitywas assessed against a total of 31 indicator organisms representing various Gram-negative and positive pathogens. The screening showed that 3 Bacillus subtilis strains (B3, B122 and B222) in particular had antimicrobial activity against some Gram-positive organisms and were selected for further studies. Itwas found that the antimicrobial substances producedwere heat stable, in-sensitive to catalase, sensitive to protease and trypsin but resistant to the proteolytic action of papain and proteinase …
The Role Of Transcription In Stationary Phase Mutagenesis In Bacillus Subtilis, Holly Anne Martin
The Role Of Transcription In Stationary Phase Mutagenesis In Bacillus Subtilis, Holly Anne Martin
UNLV Theses, Dissertations, Professional Papers, and Capstones
Stationary phase mutagenesis, also known as stress-induced or adaptive mutagenesis, is defined as the accumulation of mutations during conditions of no net growth or conditions of stress. This process has been implicated in acquiring antibiotic resistance and evasion of host immune responses in microbial pathogens and in the generation of mutations that lead to neoplasia in animal cells. Previous work has shown that defects in DNA synthesis and repair systems contribute to the formation of adaptive mutations; however the role of transcription in the accumulation of mutations is still being examined. It is speculated that transcriptional derepression leads to an …
The Role Of Rpoe In Stationary Phase Mutagenesis In Bacillus, Turquoise C. Alexander, Eduardo A. Robleto
The Role Of Rpoe In Stationary Phase Mutagenesis In Bacillus, Turquoise C. Alexander, Eduardo A. Robleto
Undergraduate Research Opportunities Program (UROP)
Stationary phase mutagenesis is a phenomenon whereby random mutations are generated in non-dividing cells. In order to understand how these mutations arise, we use Bacillus subtilis, a gram positive rod-shaped model organism. It is hypothesize that increased transcription promotes stationary phase mutagenesis in this organism. We therefore examined the role of rpoE, a gene that encodes RNA polymerase ! subunit and proposed to influence efficiency of transcription. To this end, we will first generate a strain bearing a deletion in the rpoE gene. In order to determine if this gene is important for mutagenesis, we will examine the accumulation of …
The Role Of Recn In Stationary Phase Mutagenesis In Bacillus Subtilis, Lauren E. Johnson, Katherine R. Ona, Eduardo A. Robleto, Ronald E. Yasbin
The Role Of Recn In Stationary Phase Mutagenesis In Bacillus Subtilis, Lauren E. Johnson, Katherine R. Ona, Eduardo A. Robleto, Ronald E. Yasbin
Undergraduate Research Opportunities Program (UROP)
Here, we examine mutagenic programs that are independent of growth, such aspects of the evolutionary process are novel and have been implicated in the formation of cancers in animal cells and the acquisition of antibiotic resistance in animal pathogens. Adaptive or stationary phase mutagenesis is a genetic program to in increase diversity in cells under conditions of stress whereby cells escape non-dividing conditions. Previous research has shown that recombination functions are required to generate mutations that promote growth in Escherichia coli cells starved for carbon. This project tests the hypothesis that recombination functions are required for the generation of mutations …
The Effect Of Cody On Stationary Phase Mutagenesis In Bacillus Subtilis, May Yared, Holly Martin, Eduardo A. Robleto, Ronald E. Yasbin
The Effect Of Cody On Stationary Phase Mutagenesis In Bacillus Subtilis, May Yared, Holly Martin, Eduardo A. Robleto, Ronald E. Yasbin
Undergraduate Research Opportunities Program (UROP)
We examine the notion that cells in conditions of stress accumulate mutation is in genes under selection via transcription processes. CodY is a global transcriptional regulator in many Gram positives, including soil and pathogenic microbes. In conditions of exponential growth and when branch chain amino acids and GTP are in abundance CodY acts as a transcriptional repressor of many metabolic operons. This transitional repression saves the cell energy and allows efficient use of resources. In conditions of starvation, CodY relieves repression of genes involved in acquisition of nutrients and degradation of carbon sources (genes under selection). Here, we compare the …