Microbiology Commons^™

The Effects Of Slow Release Urea On Nitrogen Metabolism In Cattle, Vaughn B. Holder

Theses and Dissertations--Animal and Food Sciences

The objective of this research was to investigate the effects of slow release urea on N metabolism in cattle. The ruminal behavior of Optigen®II and the effect of basal diet on the in situ degradability of urea and Optigen®II were evaluated. The effect of slow release urea and its interaction with degradable intake protein (DIP) level in the diet on N retention and excretion was evaluated utilizing 8 Holstein steers in a 4 x 4 Latin square experiment. In addition, the effect of slow release urea and DIP level on ruminal and systemic urea kinetics was evaluated using stable isotope …

Soil Microbial Community Response To Climate Change: Results From A Temperate Kentucky Pasture, Lindsey C. Slaughter

Theses and Dissertations--Plant and Soil Sciences

Climate change is likely to alter plant species composition and interactions between plants and soil microbes that together dictate the quantity and quality of forage produced in pastures, the base of animal production in central Kentucky. This study assessed the seasonal dynamics of soil microbes and their response to increased temperature (+3^oC) and growing season precipitation (+30% of the mean annual). Total soil microbial biomass, community composition, enzyme activities, potential carbon mineralization, and catabolic responses to selected substrates were measured seasonally in the different climate treatments. In this system, seasonal variability was a dominant driving factor for all …

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.

Novel Model For Multispecies Biofilms That Uses Rigid Gas-Permeable Lenses, Rebecca Peyyala, Sreenatha S. Kirakodu, Jeffrey L. Ebersole, Karen F. Novak

Center for Oral Health Research Faculty Publications

Oral biofilms comprise complex multispecies consortia aided by specific inter- and intraspecies interactions occurring among commensals and pathogenic bacterial species. Oral biofilms are primary initiating factors of periodontal disease, although complex multifactorial biological influences, including host cell responses, contribute to the individual outcome of the disease. To provide a system to study initial stages of interaction between oral biofilms and the host cells that contribute to the disease process, we developed a novel in vitro model system to grow biofilms on rigid gas-permeable contact lenses (RGPLs), which enable oxygen to permeate through the lens material. Bacterial species belonging to early- …

Interleukin-10 Mediated Autoregulation Of Murine B-1 B-Cells And Its Role In Borrelia Hermsii Infection, Vishal Sindhava, Michael E Woodman, Brian Stevenson, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

B cells are typically characterized as positive regulators of the immune response, primarily by producing antibodies. However, recent studies indicate that various subsets of B cells can perform regulatory functions mainly through IL-10 secretion. Here we discovered that peritoneal B-1 (B-1P) cells produce high levels of IL-10 upon stimulation with several Toll-like receptor (TLR) ligands. High levels of IL-10 suppressed B-1P cell proliferation and differentiation response to all TLR ligands studied in an autocrine manner in vitro and in vivo. IL-10 that accumulated in cultures inhibited B-1P cells at second and subsequent cell divisions mainly at the G1/S interphase. …

The Role Of Cuticle, Fatty Acids, And Lipid Signaling In Plant Defense, Ye Xia

Theses and Dissertations--Plant Pathology

Systemic acquired resistance (SAR) is initiated upon recognition of specific microbial effectors by cognate plant resistance proteins and immunizes distal tissues of plants against secondary infections. SAR involves the generation of a mobile signal at the site of primary infection, which then translocates to and activates defense responses in the distal tissues via some unknown mechanism(s). This study shows that an ACYL CARRIER PROTEIN 4 (ACP4), GLABRA1 (GL1) and ACYL CARRIER BINDING PROTEINS (ACBP) are required for the processing of the mobile SAR signal in distal tissues of Arabidopsis. Although acp4, gl1 and acbp plants generate the mobile signal, …

Yersinia Pestis Virulence Factor Yopm Undermines The Function Of Distinct Ccr2+Gr1+ Cells In Spleen And Liver During Systemic Plague, Zhan Ye

University of Kentucky Doctoral Dissertations

Yersinia pestis, the infective agent of bubonic and pneumonic plague, is classified as a category A agent of bioterrorism. YopM, a protein toxin of Y. pestis, is necessary for full virulence in a systemic plague mouse model with ambient-temperature grown bacteria. We used this model to identify the cells undermined by YopM. Natural killer (NK) cells were previously reported to be lost in spleen and blood in a YopM-associated way; however, NK cell depletion was found not to occur in liver, and ablation of NK cells had no effect on bacterial growth, indicating that NK cells are redundant …

Soil Organic Matter Fractions And Aggregate Distribution In Response To Tall Fescue Stands, I. P. Handayani, Mark S. Coyne, R. S. Tokosh

Plant and Soil Sciences Faculty Publications

The study was conducted to evaluate the influences of tall fescue management on soil organic matter fractions and macro- and microaggregate distribution. Soil samples were collected from four paired adjacent fields consisting of five years of tall fescue mono and poly stands in Western Kentucky. Soil samples from 0 to 15 cm and 15 to 30 cm soil depths were analyzed for soil organic C and N, particulate organic matter C (POM-C) and N (POM-N), macro- and micro aggregate distribution and C-associated with macro- and micro- aggregates. Significant effects were observed between stands for all the properties, except total C, …

Multimeric Hemicellulases Facilitate Biomass Conversion, Zhanmin Fan, Kurt Wagschal, Wei Chen, Michael D. Montross, Charles C. Lee, Ling Yuan

Plant and Soil Sciences Faculty Publications

Two highly active trifunctional hemicellulases were constructed by linking the catalytic portion of a xylanase with an arabinofuranosidase and a xylosidase, using either flexible peptide linkers or linkers containing a cellulose-binding domain. The multifunctional enzymes retain the parental enzyme properties and exhibit synergistic effects in hydrolysis of natural xylans and corn stover.

Soil Microbial Community Response To Hexavalent Chromium In Planted And Unplanted Soil, Ioannis Ipsilantis, Mark S. Coyne

Plant and Soil Sciences Faculty Publications

Theories suggest that rapid microbial growth rates lead to quicker development of metal resistance. We tested these theories by adding hexavalent chromium [Cr(VI)] to soil, sowing Indian mustard (Brassica juncea), and comparing rhizosphere and bulk soil microbial community responses. Four weeks after the initial Cr(VI) application we measured Cr concentration, microbial biomass by fumigation extraction and soil extract ATP, tolerance to Cr and growth rates with tritiated thymidine incorporation, and performed community substrate use analysis with BIOLOG GN plates. Exchangeable Cr(VI) levels were very low, and therefore we assumed the Cr(VI) impact was transient. Microbial biomass was reduced …

Characterization Of Dairy Milk House Waste Water In Kentucky, Anshu Singh, Czarena L. Crofcheck, Gail M. Brion

Biosystems and Agricultural Engineering Faculty Publications

This study focuses on characterization of milk house waste water from eight different farms in Kentucky. The farms were separated into three groups based on the number of cows: small (20-30), medium (30-60), and large (over 60 cows). Samples were collected once a month from four farms and twice a month from the remainder. Samples were analyzed for chemical, biochemical, and microbiological characteristics. Results indicated a large and significant variation in the chemical and microbiological characteristics between the farms. Farm size had a significant effect on the nutrient content of the waste water. Though samples exhibited seasonal variation, there was …

Effects Of Commercial Diazinon And Imidacloprid On Microbial Urease Activity In Soil And Sod, C. W. Ingram, Mark S. Coyne, David W. Williams

Plant and Soil Sciences Faculty Publications

Diazinon [O,O-diethyl O-2-isopropyl-6-methyl(pyrimidine-4-yl) phosphorothioate] and imidacloprid [1-(1-[6-chloro-3-pyridinyl]methyl)-N-nitro-2-imidazolidinimine] are applied to lawns for insect control simultaneously with nitrogenous fertilizers such as urea, but their potential effect on urease activity and nitrogen availability in turfgrass management has not been evaluated. Urease activity in enzyme assays, washed cell assays, and soil slurries was examined as a function of insecticide concentration. Intact cores from field sites were used to assess the effect of insecticide application on urease activity in creeping bentgrass (Agrostis palustris Huds.) and bluegrass (Poa pratensis L.) sod. Bacterial urease fromBacillus pasteurii and plant …

Fertilizer, Tillage, And Dairy Manure Contributions To Nitrate And Herbicide Leaching, C. S. Stoddard, John H. Grove, Mark S. Coyne, William O. Thom

Plant and Soil Sciences Faculty Publications

Few studies have examined the water quality impact of manure use in no-tillage systems. A lysimeter study in continuous corn (Zea mays L.) was performed on Maury silt loam (fine, mixed, semiactive, mesic Typic Paleudalf) to evaluate the effect(s) of tillage (no-till [NT] and chisel-disk [CD]), nitrogen fertilizer rate (0 and 168 kg N ha⁻¹), and dairy manure application timing (none, spring, fall, or fall plus spring) on NO₃–N, atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), and alachlor [2-chloro-2′-6′-diethyl-N-(methoxymethyl)acetanilide] concentrations in leachate collected at a 90-cm depth. Herbicides were highest immediately after application, declining to less …

Mortality Of Escherichia Coli O157:H7 In Two Soils With Different Physical And Chemical Properties, D. N. Mubiru, Mark S. Coyne, John H. Grove

Plant and Soil Sciences Faculty Publications

Wild and domesticated animals can harbor a pathogenic Escherichia coli strain designated as O157:H7. Potential health problems could occur if strain O157:H7 is a more robust survivor in defecated waste than commonly used indicator bacteria. A laboratory study was conducted to assess E. coli O157:H7 survival relative to a nonpathogenie E. coli strain in two soils with different physical and chemical characteristics. Bacteria in the inoculated soils were enumerated on a weekly basis for 8 wk using a most probable number (MPN) technique. First-order decay models were used to describe bacteria mortality in the soils. Decay series were described slightly …

Fecal Bacteria Survival And Infiltration Through A Shallow Agricultural Soil: Timing And Tillage Effects, C. S. Stoddard, Mark S. Coyne, John H. Grove

Plant and Soil Sciences Faculty Publications

Human and livestock exposure to fecal pathogens via contaminated surface or groundwater is an important water quality concern for soils receiving animal wastes. The effects of manure application timing (spring or fall application) and soil management (no-tillage or conservation tillage) on fecal bacteria infiltration through shallow karst soils in central Kentucky (the Bluegrass region) have not been evaluated. We performed a field experiment to measure fecal coliforms and fecal streptococci in leachate from dairy manure-amended no-tillage and conservation tillage soils. Manure significantly increased fecal bacteria in leachate compared with unmanured treatments. After manure application, the leachate that collected in zero-tension …

Fecal Coliform Transport Through Intact Soil Blocks Amended With Poultry Manure, S. W. Mcmurry, Mark S. Coyne, E. Perfect

Plant and Soil Sciences Faculty Publications

Poultry production in Kentucky increased almost 200% between 1991 and 1995. Their waste is typically land applied, and fecal pathogen runoff and infiltration may cause nonpoint source groundwater pollution. We looked at the preferential flow of fecal coliforms through undisturbed soil blocks since fecal bacteria typically infiltrate the soil profile to contaminate groundwater. Poultry manure was uniformly distributed on top of sod-covered or tilled (upper 12.5 cm) soil blocks and the blocks were irrigated. Drainage was collected in 100 uniformly spaced cells beneath each block and analyzed for fecal coliform content and drainage volume. The spatial distribution of drainage and …

Effect Of Sediment Particle Size And Temperature On Fecal Bacteria Mortality Rates And The Fecal Coliform/Fecal Streptococci Ratio, J. M. Howell, Mark S. Coyne, P. L. Cornelius

Plant and Soil Sciences Faculty Publications

Extended survival of fecal bacteria in sediment can obscure the source and extent of fecal contamination in agricultural settings. The variability in fecal coliform/fecal streptococci (FC/FS) ratios with time and discrepancies between observable fecal sources and measured FC/FS ratios in shallow surface water from agricultural watersheds may be explained by examining FC and FS mortality rates in response to ambient temperature and sediment particle size. We measured FC and FS mortality rates at three different temperatures and in three feces-amended sediments with different particle size in a laboratory study. In controlled conditions, using physiological saline to reduce cell death by …

So You Want To Be A Soil Microbiologist?, Mark S. Coyne

Plant and Soil Sciences Faculty Book Gallery

A tongue-in-cheek look at soil microbiology.

Nitrous Oxide Loss From Poultry Manure-Amended Soil After Rain, Mark S. Coyne, A. Villalba, Robert L. Blevins

Plant and Soil Sciences Faculty Publications

Land application of poultry wastes in Kentucky will increase as the broiler industry grows. If poultry manure stimulates N₂O loss from soil it will reduce the fertilizer N value of this waste. In contrast, stimulated N₂O loss in grass filter strips receiving the runoff from manured fields could help reduce contamination of surface water by NO⁻₃. Our objectives were to determine (i) if poultry manure stimulated N₂O loss in soil after rainfall and (ii) if there was an edge-of-field effect on N₂O loss in grass filters intercepting runoff from …

Fecal Bacteria In Agricultural Waters Of The Bluegrass Region Of Kentucky, J. M. Howell, Mark S. Coyne, P. L. Cornelius

Plant and Soil Sciences Faculty Publications

Agricultural runoff influenced by nonpoint pollution frequently exceeds the USEPA standards for bacterial contamination of primary contact water (200 fecal coliforms/100 mL). Few studies have evaluated the effect of cattle (Bos taurus) grazing on fecal contamination of ground water in the karst topography of central Kentucky. Our objectives were to: (i) observe the extent and pattern of fecal bacteria in agricultural waters from two central Kentucky watersheds; (ii) determine if monthly sampling accurately assessed the extent and variability of fecal contamination; and (iii) assess the fecal coliform/fecal streptococci ratio (FC/FS) as an indicator of fecal bacteria source. Springs, …

Nitrous Oxide Flux From Poultry-Manured Erosion Plots And Grass Filters After Simulated Rain, Mark S. Coyne, R. A. Gilfillen, Robert L. Blevins

Plant and Soil Sciences Faculty Publications

Adding carbon-rich materials to fields, like manure, may enhance denitrification. Grass filters, which are used to trap surface runoff from these fields, may also provide a carbon-rich environment that favors water infiltration and denitrification. Nitrous oxide (N₂O) may be evolved these settings. It is a radiatively important trace gas and intermediate in the denitrification pathway and several other microbial processes. We measured N₂O flux, after simulated rain, using a soil cover technique in poultry-manured plots and grass filters receiving their runoff. Intact soil cores were used to relate the N₂O flux to the denitrification …

Frequency Of Mug Negative Escherichia Coli In Kentucky Groundwater Samples, Mark S. Coyne, J. C. Shuler

Plant and Soil Sciences Faculty Publications

MUG negative Escherichia coli are a small fraction (2.5%) of the total E. coli in Kentucky groundwater samples. It is unlikely that they alone will cause a significant potential to underestimate fecal contamination using MUG as the primary criterion for that assessment. An unresolved question is how effectively MUG-based, defined-substrate tests address false negative water samples containing MUG positive E. coli.

Sunlight Induced Movement Of Planktonic Organisms And Their Relationships To Water Movements, John Calkins, Ed Colley, Jay Wallingford, Carol Hulsey, Kathy Lohr, Marc Bolling

KWRRI Research Reports

Previous studies have shown the planktonic organisms of various natural water bodies to be quite sensitive to the levels of solar ultraviolet radiation incident at the water surface in summer. It has been assumed that the majority of the phytoplankton are simply carried about in the mass of the water which they inhabit with little control of their position or sunlight exposure. Photosynthetic microorganisms must strike a delicate balance with regard to solar radiation; they must obtain enough visible light for adequate photosynthesis while avoiding an excessive exposure to the injurious solar UV-B radiation.

It is proposed that the circulation …

Effects Of Polychlorinated Biphenyl Compounds And Proposed Pcb-Replacement Products On Embryo-Larval Stages Of Fish And Amphibians, Wesley J. Birge, Jeffrey A. Black, Albert G. Westerman

KWRRI Research Reports

Static renewal bioassays were performed with four polychlorinated biphenyls, including Capacitor 21 and Aroclors 1016, 1242, and 1254. Each compound was used to treat embryo-larval stages of the rainbow trout (Salmo gairdneri), channel catfish (Ictalurus punctatus), goldfish (Carassius auratus), redear sunfish (Lepomis microlophus), leopard frog (Rana pipiens), Fowler's toad (Bufo fowleri), and American toad (Bufo americanus). Developmental stages of the trout were the most sensitive, with LC₅₀ 's at 4 days posthatching of 0.3, 1.0, 1.1, and 1.6 μg/l for Aroclors 1254, 1242, 1016, and …

Metabolic Capabilities Of Sulfur Oxidizing Bacteria And Their Role In Water Pollution, M. I. H. Aleem

KWRRI Research Reports

This report describes investigations into the physiology of microorganisms that are commonly involved in the oxidation of inorganic sulfur compounds. The metabolic activities of these bacteria play a potent role in several fields of economic importance such as strip mining operations, water pollution, corrosion, metallurgy, petroleum technology and soil fertility processes.

The oxidation of inorganic sulfur compounds was studied in the chemolithotrophs Thiobacillus denitrificans, Thiobacillus A₂, Thiobacillus neapolitanus, and a photolithotroph Rhodopseudomonas palustris. Cell suspensions from all of the thiobacilli catalyzed completely the oxidation of sulfide, thiosulfate, and sulfite to sulfate. The oxidation of thiosulfate in R. palustris …

Ecological Study Of The Effects Of Strip Mining On The Microbiology Of Streams, Ralph H. Weaver, Harry D. Nash

KWRRI Research Reports

The microflora of Cane Branch of Beaver Creek in McCreary County, Kentucky, which drains an area that was strip-mined between 1955 and 1959, was studied and compared with that of Helton Branch which drains a comparable area where there has been no mining. Differences include: the establishment of Ferrcbacillus ferrooxidans, for which procedures were developed for direct colony isolation from the stream; fewer saprophytic bacteria; more numerous and more diversified filamentous and unicellular fungi; and characteristic differences in algal flora. Representatives of 42 genera of filamentous fungi were identified. Of these, 21 were isolated only from Cane Branch. Representatives of …