A New Class Of Homoserine Lactone Quorum-Sensing Signals,
2012
University of Washington, Seattle
A New Class Of Homoserine Lactone Quorum-Sensing Signals, Amy Schaefer, E Greenberg, Colin Oliver, Yasuhiro Oda, Jean Huang, Gili Bittan-Banin, Caroline Peres, Silke Schmidt, Katarina Juhaszova, Janice Sufrin, Caroline Harwood
Jean J. Huang
Quorum sensing is a term used to describe cell-to-cell communication that allows cell-density-dependent gene expression. Many bacteria use acyl-homoserine lactone (acyl-HSL) synthases to generate fatty acyl-HSL quorum-sensing signals, which function with signal receptors to control expression of specific genes. The fatty acyl group is derived from fatty acid biosynthesis and provides signal specificity, but the variety of signals is limited. Here we show that the photosynthetic bacterium Rhodopseudomonas palustris uses an acyl-HSL synthase to produce p-coumaroyl-HSL by using environmental p-coumaric acid rather than fatty acids from cellular pools. The bacterium has a signal receptor with homology to fatty acyl-HSL receptors …
Acyl‐Hsl Signal Decay: Intrinsic To Bacterial Cell–Cell Communications,
2012
California Institute of Technology
Acyl‐Hsl Signal Decay: Intrinsic To Bacterial Cell–Cell Communications, Ya-Juan Wang, Jean Huang, Jared Leadbetter
Jean J. Huang
No abstract available.
The Acid Stress Response Of The Cyanobacterium Synechocystis Sp. Strain Pcc 6308,
2012
Franklin W. Olin College of Engineering
The Acid Stress Response Of The Cyanobacterium Synechocystis Sp. Strain Pcc 6308, Jean Huang, Nancy Kolodny, Jennifer Redfearn, Mary Allen
Jean J. Huang
The cyanobacterium Synechocystis sp. strain PCC 6308 has been shown to exhibit predictable physiological responses to acid stress. Originally isolated from a Wisconsin lake, this cyanobacterium grows optimally under alkaline conditions in the laboratory. After acid stress at a pH of between 4.4 and 7.7, cells return to exponential growth following a lag phase. The organism's response to this tolerable acid stress involves cell concentration-dependent neutralization of the external medium to pH 6 or above within 5 min, maintenance of a transmembrane pH gradient, and maintenance of photosystem II efficiency. Lethal acid stress, at a pH below 4.4, results in …
Diversity And Activity Of Roseobacters And Roseophage,
2012
University of Tennessee, Knoxville
Diversity And Activity Of Roseobacters And Roseophage, Charles Ryan Budinoff
Doctoral Dissertations
Bacteria of the Roseobacter lineage are dominant bacterioplankton in coastal systems and contribute significantly to secondary production in oceanic environments. Generalities of Roseobacter ecology, diversity, and distributions are known, but the intraspecific differences between species and their dynamics over short temporal periods is not well understood. Bacteriophage that infect Roseobacters (‘roseophage’) have the potential to shunt secondary production into the dissolved carbon pool and through the process of infection alter Roseobacter physiology. Despite their significance, little effort was made prior to the onset of this study to characterize roseophage. Using culture dependent and independent approaches, I describe the diversity and …
The Use Of Diatoms To Infer Environmental Change Of The Lower White River, Southeastern Arkansas,
2012
University of Arkansas, Fayetteville
The Use Of Diatoms To Infer Environmental Change Of The Lower White River, Southeastern Arkansas, Ruchi Bhattacharya
Graduate Theses and Dissertations
This dissertation describes the limnology of the lower White River oxbow lakes in southeast Arkansas, inundated by the major 2008 spring flood. The flood water and sediment deposited in oxbow lakes were analyzed for water chemistry, sediment geochemistry and diatom assemblages and used as an analogue for past floods. The 2008 spring flood inundated and homogenized the entire floodplain; also represented by the predominantly planktonic diatom assemblage suggesting riverine input. Indicator species for eutrophication were also recorded consistent with the high nutrient content in the lakes. However, the variance in the surface diatom assemblage was best explained by the lake …
The Effects Of Nutrient Limitation And Cyanophage On Heterotrophic Microbial Diversity,
2012
University of Tennessee, Knoxville
The Effects Of Nutrient Limitation And Cyanophage On Heterotrophic Microbial Diversity, Claire Elyse Campbell
Masters Theses
Marine viruses are critically important in the regulation of biogeochemical cycles and host microbial communities. In this study, we tested whether the indirect effects of virus predation on a phototroph (i.e., Synechococcus) affected the composition of co-occurring heterotrophic bacteria under nitrogen and phosphorus limitation in long-term chemostat experiments. Using 454 Titanium barcoded pyrosequencing of the 16S rRNA gene, microbial diversity and technical (i.e., sequencing) reproducibility were assessed for nine individual chemostats across five different time points. A total of 325,142 reads were obtained; 194,778 high-quality, non-cyanobacterial sequences were assigned to 110 OTUs. Our results show high reproducibility …
Investigation Of Bacillus Subtilis As A Biopesticide Against Botrytis Cinerea,
2012
California Polytechnic State University, San Luis Obispo
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 …
Bacteria And Fungi Cultured From Sand, Cloacal Fluids, And Unhatched Eggs Of Olive Ridley Sea Turtles And Standard Testing Of Antimicrobial Properties Of Cloacal Fluids,
2012
Indiana University - Purdue University Fort Wayne
Bacteria And Fungi Cultured From Sand, Cloacal Fluids, And Unhatched Eggs Of Olive Ridley Sea Turtles And Standard Testing Of Antimicrobial Properties Of Cloacal Fluids, Erin Keene, Tanya Soule, Frank Paladino
Tanya Soule
No abstract provided.
Investigation Of The Relationship Between Extracellular Slime Layer And Sunscreen Production In Nostoc Punctiforme,
2012
Indiana University - Purdue University Fort Wayne
Investigation Of The Relationship Between Extracellular Slime Layer And Sunscreen Production In Nostoc Punctiforme, Pavan Paten, Dexter Shipe, Tanya Soule
Tanya Soule
No abstract provided.
Removing 17Β-Estradiol From Drinking Water In A Biologically Active Carbon (Bac) Reactor Modified From A Granular Activated Carbon (Gac) Reactor,
2012
University of Nebraska – Lincoln
Removing 17Β-Estradiol From Drinking Water In A Biologically Active Carbon (Bac) Reactor Modified From A Granular Activated Carbon (Gac) Reactor, Zhongtian Li
Z Li
Estrogenic compounds in drinking water sources pose potential threats to human health. Treatment technologies are needed to effectively remove these compounds for the production of safe drinking water. In this study, GAC adsorption was first tested for its ability to remove a model estrogenic compound, 17β-estradiol (E2). Although GAC showed a relatively high adsorption capacity for E2 in isotherm experiments, it appeared to have a long mass transfer zone in a GAC column reactor, causing an early leakage of E2 in the effluent. With an influent E2 concentration of 20 μg/L, the GAC reactor was able to bring down effluent …
Soil Bacterial Communities Of A Calcium-Supplemented And A Reference Watershed At The Hubbard Brook Experimental Forest (Hbef), New Hampshire, Usa,
2012
University of New Hampshire
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 …
Bacteria And Fungi Cultured From Sand, Cloacal Fluids, And Unhatched Eggs Of Olive Ridley Sea Turtles And Standard Testing Of Antimicrobial Properties Of Cloacal Fluids,
2012
Indiana University - Purdue University Fort Wayne
Bacteria And Fungi Cultured From Sand, Cloacal Fluids, And Unhatched Eggs Of Olive Ridley Sea Turtles And Standard Testing Of Antimicrobial Properties Of Cloacal Fluids, Erin Keene, Tanya Soule, Frank Paladino
Tanya Soule
No abstract provided.
Purification And Characterization Of Novel Nucleases From A Thermophilic Fungus,
2012
University of Massachusetts Amherst
Purification And Characterization Of Novel Nucleases From A Thermophilic Fungus, Kyle S. Landry
Masters Theses 1911 - February 2014
A thermophilic fungus was isolated from composted horse manure. The organism was as a Chaetomium sp. by sequencing the highly conserved ITS region of the fungus and comparing to known regions in a genomic database and was referred to as TM-417. TM-417 was found to have an optimal growth temperature of 45 oC and an optimal pH of 7.0. An extracellular DNase and RNase was found to be produced by the isolate and were purified 145.58-fold and 127.6-fold respectively using a combination of size exclusion chromatography and a novel affinity membrane purification system. The extent of purification was determined …
Thoughts On Quorum Sensing And Fungal Dimorphism,
2012
University of Nebraska-Lincoln
Thoughts On Quorum Sensing And Fungal Dimorphism, Kenneth W. Nickerson, Audrey L. Atkin, Jessica C. Hargarten, Ruvini U. Pathirana, Sahar Hasim
Papers in Microbiology
Farnesol has been best studied for its role in regulating fungal dimorphism. However, farnesol is also a lipid and in this review we analyze data relevant to farnesol’s function and synthesis from the perspective of farnesol and bacterial endotoxins acting as membrane active compounds. This analysis implicates the possible roles of: (1) endotoxins in the regulation of farnesol production by C. albicans; (2) farnesol in the interactions between C. albicans and the host during disseminated infections; and (3) ubiquinones in the mechanisms for unusually high resistance to farnesol by some C. albicans cell types. Finally we discuss the implications …
Bacterial Community Structure Of Contrasting Soils Underlying Bornean Rain Forests: Inferences From Microarray And Next-Generation Sequencing Methods,
2012
University of Nebraska - Lincoln
Bacterial Community Structure Of Contrasting Soils Underlying Bornean Rain Forests: Inferences From Microarray And Next-Generation Sequencing Methods, Sabrina E. Russo, Ryan Legge, Karrie A. Weber, Eoin L. Brodie, Katherine C. Goldfarb, Andrew K. Benson, Sylvester Tan
School of Biological Sciences: Faculty Publications
Soil microbial diversity is vast, and we lack even basic understanding of how this diversity is distributed ecologically. Using pyrosequencing and microarray methods, we quantified the structure of bacterial communities in two contrasting soils underlying Bornean rain forest (clay and sandy loam) that differ markedly in soil properties, aboveground tree flora, and leaf litter decomposition rates. We found significant soil-related taxonomic and phylogenetic differences between communities that, due to their proximity, are independent of climate. Bacterial communities showed distinct compositional and taxon-abundance distributions that were significantly correlated with the structure of the overlying tree community. Richness of bacteria was greater …
Stability Of Antibiotic Resistance Patterns In Agricultural Pastures: Lessons From Kentucky, Usa,
2012
University of Kentucky
Stability Of Antibiotic Resistance Patterns In Agricultural Pastures: Lessons From Kentucky, Usa, Sloane Ritchey, Siva Gandhapudi, Mark Coyne
Plant and Soil Sciences Faculty Publications
No abstract provided.
Control And Passive Treatment Of Runoff From Horse Muck Storage Structures Using Rain Gardens,
2012
University of Kentucky
Control And Passive Treatment Of Runoff From Horse Muck Storage Structures Using Rain Gardens, Hillary K. Otte
Theses and Dissertations--Forestry and Natural Resources
Runoff from livestock operations may contain a variety of pathogens and high levels of nutrients and other harmful contaminants, and is of particular concern in central Kentucky as watersheds are threatened by waste generated from a high concentration of equine activity. Rain gardens are a type of stormwater management tool used to capture and passively treat runoff. This project aimed to incorporate rain gardens into the horse muck storage structures at a thoroughbred facility in the Canr Run watershed in Lexington, Kentucky. Water quality data from soil water within two rain garden muck pads and two control pads, and grab …
Science Needs More Moneyball,
2012
Wesleyan University
Science Needs More Moneyball, Frederick Cohan
Frederick M. Cohan
No abstract provided.
Demarcation Of Bacterial Ecotypes From Dna Sequence Data: A Comparative Analysis Of Four Algorithms,
2012
Wesleyan University
Demarcation Of Bacterial Ecotypes From Dna Sequence Data: A Comparative Analysis Of Four Algorithms, Juan Francisco, Frederick Cohan, Danny Krizanc
Frederick M. Cohan
No abstract provided.
Prokaryotic Sex: Eukaryote-Like Qualities Of Recombination In An Archaean Lineage,
2012
Wesleyan University
Prokaryotic Sex: Eukaryote-Like Qualities Of Recombination In An Archaean Lineage, Frederick Cohan, Stephanie Aracena
Frederick M. Cohan
No abstract provided.
