Microbiology Commons^™

Genistein-Enriched Pig Gut Microbiota Library As A Potential Probiotic Consortium, Theresah Amponsah

Electronic Theses and Dissertations

Plant-based diets contain numerous flavonoid compounds that produce antibacterial effects and gut health improvement. Genistein is among the most abundant isoflavones present in a plant-based diet and can be found in high amounts in soy products (up to 1g Kg-1). We describe here a robust method to identify genistein tolerant and metabolizing bacteria in swine gut microbiota and to screen the strains that have antibacterial and immunestimulatory properties. Such strains could be developed as non-antibiotic alternatives to prevent enteric infections in pigs and improve gut immunity. To this end, a mini bioreactorbased system was used to enrich genistein metabolizing bacteria …

D-Lactic Acid Fermentation Platform From Oil Palm Trunk Sap By Sporolactobacillus Terrae Sbt-1, Naphatsawan Sukaiem

Chulalongkorn University Theses and Dissertations (Chula ETD)

Lactic acid is an organic acid that contains two enantiomers, L- and D-lactic acid, and is considered the most potential monomer for many industrial products. Lactic acid has versatile applications in the pharmaceutical, food, textile, chemical, and leather industries moreover in poly-lactic acid (PLA) manufacturing. While L-lactic acid is well known in many commercial products and studies, only a few studies on D-lactic acid were found. Lactic acid can be produced either by microbial fermentation or chemical synthesis. Approximately 90 percent of the total lactic acid produced worldwide is via microbial fermentation which provides an optically pure L- or D-lactic …

An Integrative Investigation Of The Synechococcus A/B Clade During Adaptive Radiation At The Upper Thermal Limit Of Phototrophy, Christopher L. Pierpont

Graduate Student Theses, Dissertations, & Professional Papers

Thermophilic microorganisms have been scientifically observed since the early nineteenth century and have spurred many questions about the limits of life and the capacity of organisms to survive extreme conditions. Decades of research on thermophile proteins and genomes have yielded several proposed correlates of temperature that may contribute to adaptation of bacteria and archaea to high temperature. However, many of the generalizations reported are drawn from analyses of deeply divergent taxa or from individual case studies in isolation from mesophilic relatives. Members of the Synechococcus A/B (SynAB) group are the only cyanobacteria with members able to grow above 65 °C …

An Optimal Lysis Time Maximizes Bacteriophage Fitness In Quasi-Continuous Culture, Sherin Kannoly, Abhyudai Singh, John J. Dennehy

Publications and Research

Optimality models have a checkered history in evolutionary biology. While optimality models have been successful in providing valuable insight into the evolution of a wide variety of biological traits, a common objection is that optimality models are overly simplistic and ignore organismal genetics. We revisit evolutionary optimization in the context of a major bacteriophage life history trait, lysis time. Lysis time refers to the period spanning phage infection of a host cell and its lysis, whereupon phage progenies are released. Lysis time, therefore, directly determines phage fecundity assuming progeny assembly does not exhaust host resources prior to lysis. Noting that …

Effects Of Copper Fungicides Spray On Nutrient Contents In Soils Of Cocoa Growing Areas Of Southwestern Nigeria, Musibau O Azeez, Olusola O Adesanwo, Joseph A Adepetu

Tanzania Journal of Science

The present study aimed at evaluating the effects of copper fungicides spray on physical and chemical properties of soils of cocoa growing areas of southwestern Nigeria. Samples were collected from selected cocoa farms and adjacent plots across three states (9 samples from Osun State, 9 samples from Ondo State and 7 samples from Ekiti State), within rainforest zone of Nigeria. The physical and chemical properties of the soil samples were determined. Copper contents of the cocoa plantation soils were significantly higher (16.23 mg Cu/kg) than the adjacent plots (6.31 mg Cu/kg) indicating accumulation of Cu in the soil because of …

Placental Insulin-Like Growth Factor-1 Receptor, Protein Kinase B And Mammalian Target Of Rapamycin Are Downregulated In Hiv-1 Positive Women On Antiretroviral Drugs, Winifrida B. Kidima, Gatambwa D. Mukandala, Osiana Leonard, Daniel Nkungu

Tanzania Journal of Science

HIV-1 and ARV drugs uptake during pregnancy may change placental phenotype during pregnancy affecting fetal growth. We investigated the influence of maternal HIV-1 and ARV drugs on expression of placental genes important for fetus growth. A total 51 HIV-1 positives and 46 HIV-1 negative pregnant women were studied. Placental gene expression changes of insulin-like growth factor receptor 1 (IGF-1) R, mammalian target of rapamycin (mTOR), protein kinase B (AKT-1), sodium-coupled neutral amino acid transporters (Slc38a1, Slca38a2, Slc38a4), inhibin A, adrenomedullin and 11 beta-Hydroxysteroid dehydrogenase type (HSD)-2 were assessed by RT-qPCR. There was a significant decrease in mRNA expression of placental …

Preparation, Characterization, And Antimicrobial Activities Of Mixed Ibuprofen-Salicylic Acid Metal-Drug Complexes, Mercy O Bamigboye, Ikechukwu P Ejidike, Racheal O Awolope, Joshua A Obaleye, Favour K. Ejimofor

Tanzania Journal of Science

Most variants of bacteria are resistant to traditional antibiotics which are organic. To overcome the growing infections, bacteria resistant infections, and multiple drug resistance (MDR) rates, transition metals with biological importance were coordinated to organic ligands (Ibuprofen and Salicylic acid) with anti-inflammatory properties. In this study, metal complexes of mixed Ibuprofen and Salicylic acid were prepared using a standard method to give of the type [M(Ibu)(Sal)X] (where M = Fe2+, Ni2+, Cu2+, and X = Cl2, Ibu = Ibuprofen, Sal = Salicylic acid). The complexes were characterized by UV-visible spectroscopy, conductivity measurements, melting points, FT-IR, and X-ray diffraction. The metal …

Identification And Characterization Of Cassava Mosaic Begomoviruses In Non-Crop Plants From Unguja And Pemba Islands, Joseph A. Mwakosya, Gladness E. Temu, Joseph C. Ndunguru

Tanzania Journal of Science

Cassava mosaic disease caused by cassava mosaic begomoviruses (CMBs) remains one of themajor constraints to cassava production since it causes yield losses up to 100%. Researchesshowed that some of CMBs infecting cassava plants may be coming from non-crop plants. Thisstudy intended to identify and characterize CMBs isolated from non-crop plant species inUnguja and Pemba Islands. A total of 108 viral symptomatic and asymptomatic non-crop leafsamples were collected using stratified sampling. DNA was extracted by using CTAB protocolfollowed by polymerase chain reaction using universal and specific primers for cassava mosaicbegomoviruses identification. Results showed that, among eleven samples that were amplified,four were …

Antimicrobial Activity Of Ferulic Acid In Indonesian Purple Rice Through Toll-Like Receptor Signaling, Ernanin Dyah Wijayanti, Anna Safitri, Dian Siswanto, Lidwina Faraline Triprisila, Fatchiyah Fatchiyah

Makara Journal of Science

Purple rice is a potential source of ferulic acid, which has antimicrobial properties. However, the inhibitory mechanism of ferulic acid on the growth of bacteria, particularly Salmonella and Listeria, has not been elucidated. This study aimed to determine the bioactivity of ferulic acid from purple rice as an antimicrobial agent against Salmonella typhimurium and Listeria monocytogenes using in vitro and in silico analyses. The antimicrobial activity of a purple rice ferulic acid extract was tested using the agar well diffusion method. Its effect on bacterial cells was observed using scanning electron microscopy. Ferulic acid was confirmed to have antimicrobial …

An Investigation Into The Prevalence Of Vancomycin-Resistant Enterococci Within An Irish Hospital, Dylan Casey

International Undergraduate Journal of Health Sciences

Vancomycin-resistant enterococci (VRE) are well-recognised nosocomial pathogens that pose a significant threat to public health. Associated with poorer clinical outcomes than their vancomycin-sensitive counterparts, the prevalence of VRE in Ireland has increased in recent times, with the European Antimicrobial Resistance Surveillance Network reporting that out of 29 countries, Ireland demonstrated the highest rates of vancomycin resistance among invasive Enterococcus faecium isolates between 2011 and 2014 (2011; 34.9%, 2012; 44.0%, 2013; 42.7%, 2014; 45.1%). Herein, we investigate VRE prevalence in the Mercy University Hospital (MUH) – an acute care hospital in southern Ireland. A total of 21 first-time VRE infections were …

A Mathematical Model For Transport And Growth Of Microbes In Unsaturated Porous Soil, Harihar Khanal, Andrei Ludu, Ramesh Chandra Timsina, Kedar Nath Uprety

Publications

In this work, we develop a mathematical model for transport and growth of microbes by natural (rain) water infiltration and flow through unsaturated porous soil along the vertical direction under gravity and capillarity by coupling a system of advection diffusion equations (for concentration of microbes and their growth-limiting substrate) with the Richards equation. (e model takes into consideration several major physical, chemical, and biological mechanisms. (e resulting coupled system of PDEs together with their boundary conditions is highly nonlinear and complicated to solve analytically. We present both a partial analytic approach towards solving the nonlinear system and finding the main …

High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig

Publications and Research

Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however, the lack of a highresolution structure of oxygen-evolving PSII from this organism has limited the interpretation of biophysical data to models based on structures of thermophilic cyanobacterial PSII. Here, we report the cryo-electron microscopy structure of PSII from Synechocystis sp. PCC 6803 at 1.93-Å resolution. A number of differences are observed relative to thermophilic PSII structures, including the following: the extrinsic subunit PsbQ is maintained, the C terminus of the …

Monitoring Photosynthetic Activity Using In Vivo Chlorophyll A Fluorescence In Microalgae And Cyanobacteria Biofilms In The Nerja Cave (Malaga, Spain), Yolanda Del Rosal, Juan Muñoz-Fernández, Paula S.M. Celis-Plá, Mariona Hernández-Mariné, Félix Álvarez-Gómez, Salvador Merino, Félix L. Figueroa

International Journal of Speleology

The characterization of the most common photosynthetic biofilms in the Nerja Cave by the continuous monitoring of the in vivo chlorophyll a (Chl a) fluorescence and the incorporation of the irradiance as a new environmental variable related to previous studies in the cave, have allowed us to improve our knowledge about the photosynthetic pattern of the biofilms of the cave. Effective quantum yield (ΔF/F_m′) and relative electron transport rate (rETR) were determined during periods of the light, whereas the maximal quantum yield (F_v /F_m) was determined during dark periods. Increases in …

Stimulation Of Ammonia Oxidizer And Denitrifier Abundances By Nitrogen Loading: Poor Predictability For Increased Soil N2o Emission, Yong Zhang, Feng Zhang, Diego Abalos, Yiqi Luo, Dafeng Hui, Bruce A. Hungate, Pablo García-Palacios, Yakov Kuzyakov, Jørgen Eivind Olesen, Uffe Jørgensen, Ji Chen

Biology Faculty Research

Unprecedented nitrogen (N) inputs into terrestrial ecosystems have profoundly altered soil N cycling. Ammonia oxidizers and denitrifiers are the main producers of nitrous oxide (N₂O), but it remains unclear how ammonia oxidizer and denitrifier abundances will respond to N loading and whether their responses can predict N-induced changes in soil N₂O emission. By synthesizing 101 field studies worldwide, we showed that N loading significantly increased ammonia oxidizer abundance by 107% and denitrifier abundance by 45%. The increases in both ammonia oxidizer and denitrifier abundances were primarily explained by N loading form, and more specifically, organic N …

Farnesol Secretion As A Possible Driving Force For Maintaining Candida Albicans As A Diploid, Kenneth Nickerson, Cory Boone, Kory Parker

Kenneth Nickerson Papers

Candida albicans is a pathogenic dimorphic fungus which is invariably found as a diploid in patients. C. albicans secretes the sesquiterpene farnesol both as a quorum sensing molecule which blocks the yeast to hypha conversion and as a virulence factor for pathogenicity. 20-25 μM farnesol kills other competing yeasts and fungi, often by triggering apoptosis, and yet wild type diploid C. albicans tolerates 300-500 μM farnesol. The recent availability of 10 haploid strains of C. albicans (5 mating type aand 5 mating type α) allowed us to compare their production of and sensitivity to farnesol. On average, the heterozygous diploid …

Analysis Of Spore Shape Determination In Streptomyces, Ning Sun

Electronic Theses and Dissertations

Streptomycetes are Gram-positive, soil-dwelling bacteria that possess a complex life cycle with the alternation of vegetative mycelium, aerial mycelium, and spores. Streptomyces. coelicolor spore maturation is a complex process that involves spore shape metamorphosis from cylindrical pre-spores into ellipsoid spores, but the details of this process have remained enigmatic. Previously, our lab identified a novel gene ssdA that might play a role in spore shape determination using a transposon-based insertion mutagenesis in S. coelicolor. In this study, I isolated a S. coelicolor ssdA-null mutant that showed increased colony hydrophobicity and misshapen spores in sizes and shapes, confirming the …

Metabolic Heterogeneity And The Roles Of Cody And Ccpa In Central Metabolism And S. Aureus Biofilm Formation., Logan L. Bulock

Theses & Dissertations

Staphylococcus aureus is a metabolically versatile human pathogen, causing disease in many areas of the body. Its versatility can be attributed to the fact that it utilizes a variety of tools to adapt to many different environments, including toxins to scavenge from the host and multiple transporters to compete for its preferred carbon sources. S. aureus can also survive in harsh conditions through biofilm development, which are notoriously recalcitrant to antibiotics and immune defenses. Biofilms exhibit marked heterogeneity, with division of labor for production of matrix components and differential gene expression among various niches within the biofilm.

In this study, …

Understanding The Impact Of Chlamydia Trachomatis Infection On Host Vesicular Trafficking, Lisa M. Jorgenson

Theses & Dissertations

Chlamydia trachomatis is a highly evolved obligate intracellular bacterial pathogen. During infection, organisms reside within a host epithelial cell in a membrane-bound vacuole called the inclusion. The inclusion membrane contains both pathogen and host components, including unique chlamydial type III effector proteins called Incs and host lipids like cholesterol and sphingomyelin. The inclusion membrane serves as the main barrier between the bacteria and the host cytosol, and thus, functions as the platform supporting host-chlamydial interactions. Via the inclusion membrane, C. trachomatis intercepts components of host vesicular traffic including many host SNARE proteins, which are a conserved family of eukaryotic proteins …

Skin Bacterial Metacommunities Of San Francisco Bay Area Salamanders Are Structured By Host Genus And Habitat Quality., Shannon Buttimer, Obed Hernandez-Gomez, Erica Bree Rosenblum

Natural Sciences and Mathematics | Faculty Scholarship

Host-associated microbial communities can influence physiological processes of macroorganisms, including contributing to infectious disease resistance. For instance, some bacteria that live on amphibian skin produce antifungal compounds that inhibit two lethal fungal pathogens, Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Therefore, differences in microbiome composition among host species or populations within a species can contribute to variation in susceptibility to Bd/Bsal. This study applies 16S rRNA sequencing to characterize the skin bacterial microbiomes of three widespread terrestrial salamander genera native to the western United States. Using a metacommunity structure analysis, we identified dispersal barriers for these influential bacteria between salamander …

Phage Commander, An Application For Rapid Gene Identification In Bacteriophage Genomes Using Multiple Programs, Matt Lazeriff, Geordie Ryder, Sarah L. Harris, Philippos K. Tsourkas

Computer Science Faculty Research

The number of sequenced bacteriophage genomes is growing at an exponential rate. The majority of sequenced bacteriophage genomes are annotated by one or more of several freely available gene identification programs (Glimmer, GeneMark, RAST, Prodigal, etc.). No program has been shown to consistently outperform the others; thus, the choice of which program to use is not obvious. We present the Phage Commander application for rapid identification of bacteriophage genes using multiple gene identification programs. Phage Commander runs a bacteriophage genome sequence through nine gene identification programs (and an additional program for identification of tRNAs) and integrates the results within a …