Organisms Commons^™

The Discovery Of Metarhizium Anisopliae (Metchnikoff) Sorokin Isolates From Arkansas And Their Pathogenicity To Amblyomma Americanum L., Austin Goldsmith

Graduate Theses and Dissertations

The lone star tick Amblyomma americanum L. is the most abundant tick in Arkansas and has been implicated as a vector of many important disease-causing pathogens. Many species of entomopathogenic fungi have been isolated from several species of ticks, with some of these fungi being utilized for tick biocontrol. However, few studies have assessed the pathogenicity of entomopathogenic fungi to A. americanum. The objectives of this study were to: isolate and identify native Arkansas isolates of entomopathogenic fungi from wild A. americanum ticks exposed to soil and to compare the pathogenicity of one isolate (Metarhizium anisopliae (Metchnikoff) Sorokin isolate Savoy …

Use Of Diatomaceous Earth And Copper Oxide Wire Particles To Control Gastrointestinal Nematodes In Lambs, Olivia Jones

Animal Science Undergraduate Honors Theses

Abstract

Anthelmintic resistance (AR) urges alternatives to control gastrointestinal nematodes (GIN). Copper oxide wire particles (COWP) are more efficacious when used with other dewormers and little is known on efficacy of diatomaceous earth (DE) to control gastrointestinal parasites. The objective was to examine the effects of DE and COWP on GIN control. Katahdin lambs (n = 32; ~150 d of age; 25.0 ± 1.8 kg) were randomly assigned to receive: 1) DE fed at an estimated 2% dry matter intake (with the assumption of moderate consumption of bermudagrass forage and provided supplement), 2) 1g COWP, 3) both 2% DE and …

The Effect Of Prescribed Burning On Wood-Decay Fungi In The Forests Of Northwest Arkansas, Nawaf Ibrahim Alshammari

Graduate Theses and Dissertations

Prescribed burning is defined as the process of the planned application of fire to a predetermined area under specific environmental conditions in order to achieve a desired outcome such as land management. This project used both morphological and molecular methods to identify and characterize the wood-decay fungi associated with the forests of northwest Arkansas—Pea Ridge National Military Park, Devil’s Den State Park, and the Buffalo National River—through frequent visits made between February 2018 and February 2019. In addition, in order to assess the effects of prescribed burning, incubation chambers were used to compare the growth of fungi from both unburned …

Selectivity Of Infrared Heat Treatment On Inactivation Of Mycotoxigenic Fungi On Stored Grain, Shantae A. Wilson

Graduate Theses and Dissertations

Selective Infrared (IR) heating holds great potential to decontaminate spores of unsafe fungi in corn. The objectives for this study were to investigate the impact of exposing corn to infrared energy at selected peak wavelengths (λ), infrared intensities and treatment durations, followed by tempering for further inactivation of microbes on the grain and explore a method for decontaminating Aspergillus flavus (A. flavus) spores on corn. Freshly harvested corn with initial moisture contents (IMCs) of 16%, 20%, and 24% wet basis (w.b.) were used. The corn samples were treated at different infrared wavelengths (3.2, 4.5, and 5.8 μm) for 20, 40 …

Effect Of Macrograzers (Campostoma Spp. And Faxonius Spp.) On Periphyton In Ozark Streams With Considerations Given To Macrograzer Biomass, Phosphorus, And Season: Mensurative And Manipulative Studies, Kayla R. Sayre

Graduate Theses and Dissertations

Nutrient and benthic algal biomass relationships can guide numeric nutrient criteria development in lotic systems. However, herbivorous macrograzers may confound this relationship by reducing the slope of the positive relationship between nutrients and periphyton biomass in streams. I conducted a mensurative field study to determine if stoneroller and crayfish abundance related to algal biomass at varying nutrient concentrations and manipulated macrograzer presence with electrical exclosures in streams to examine macrograzer effects on algal biomass and understand whether these effects on periphyton varied with total phosphorus (TP) or season. Macrograzer density was quantified across a TP gradient (n=15 streams; range = …

Fungi Of Forests: Examining The Diversity Of Root-Associated Fungi And Their Responses To Acid Deposition, Donald Jay Nelsen

Graduate Theses and Dissertations

Global importance of forests is difficult to overestimate, given their role in oxygen production, ecological roles in nutrient cycling and supporting numerous living species, and economic value for industry and as recreational zones. Fitness of the forest-forming trees strongly depends on microbial communities associated with tree roots. In particular, fungi impact tree fitness: mycorrhizal species provide water and nutrients for the trees in exchange for C, endophytic fungi play key roles in host defense against pathogenic organisms, and saprotrophic fungi decompose dead organic matter and facilitate nutrient cycling. In addition, pathogenic fungal species strongly affect forest fitness. Despite their importance, …

Characterization Of A Novel Fungal-Specific Gene, Fug1, In Fusarium Verticillioides, John Byron Ridenour

Graduate Theses and Dissertations

Filamentous fungi are responsible for numerous plant and animal diseases. The filamentous ascomycete Fusarium verticillioides is a globally important pathogen of maize, capable of causing severe yield reductions and economic losses. Also of substantial concern is the contamination of infected kernels with fumonisins, toxic secondary metabolites linked to toxicoses in humans and livestock. The number of sequenced fungal genomes is rapidly increasing. However, functional characterization of fungal genes has not progressed at a comparable rate. In pathogenic fungi, uncharacterized genes represent a source for novel virulence factors or anti-fungal targets. Therefore, to fully understand the genetic mechanisms underlying fungal pathogenesis, …

Sampling Local Fungal Diversity In An Undergraduate Laboratory Using Dna Barcoding, A. H. Harrington, A. F. Bigott, B. W. Anderson, M. J. Boone, S. M. Brick, J. F. Delsol, R. A. Hotchkiss, R. A. Huddleston, E. H. Kasper, J. J. Mcgrady, M. L. Mckinnie, M. V. Ottenlips, N. E. Skinner, K. C. Spatz, A. J. Steinberg, F. Van Den Broek, C. N. Wilson, A. M. Wofford, A. M. Willyard

Journal of the Arkansas Academy of Science

Traditional methods for fungal species identification require diagnostic morphological characters and are often limited by the availability of fresh fruiting bodies and local identification resources. DNA barcoding offers an additional method of species identification and is rapidly developing as a critical tool in fungal taxonomy. As an exercise in an undergraduate biology course, we identified 9 specimens collected from the Hendrix College campus in Conway, Arkansas, USA to the genus or species level using morphology. We report that DNA barcoding targeting the internal transcribed spacer (ITS) region supported several of our taxonomic determinations and we were able to contribute 5 …

Relationships Between Landscape Factors And Crayfish Density And The Interacting Effects Of Grazing And Increased Sedimentation On Algal Biomass, Katheryn Haley Rose

Graduate Theses and Dissertations

In recent years in the United States there has been a rapid expansion in anthropogenic sources of sediment in streams including construction, agriculture, and drilling for natural gas. Potential effects land disturbance associated with activities from natural gas development on aquatic biota in surrounding streams have not yet been well documented. An increase in inorganic sediment in streams can be detrimental to organisms through a variety of mechanisms including alteration of dominant substrate type, higher turbidity resulting in lower visibility, and burial of food resources such as algae and detritus. Increasing sedimentation in stream environments through anthropogenic disturbance is a …

Development Of Novel Antifungal Peptides Based On A Natural Model Of Histatin-5 Peptide, Duy Tu Nguyen

Graduate Theses and Dissertations

Our research group is working toward the development of novel antifungal peptides based on a natural model of peptide histatin-5. Histatin-5 is found in human saliva and known to protect our body against oral infections by Candida species. Candidiasis, or an infection caused by Candida species, is considered one of the most medically important fungal infections worldwide. Blood stream infections caused by Candida species are the fourth leading cause of hospital-acquired fungal infections that is associated with high mortality rates and high costs of treatment. This study investigated the modes of action of histatin-5 with the use of one 16-mer …

Role Of Lactic Acid Bacteria As A Bio-Sanitizer To Prevent Attachment Of Listeria Monocytogenes On Deli Slicer Contact Surfaces, And The Influence Of Listeria Innocua On The Attachment Of L. Monocytogenes On Selected Materials Located In The Food-Processing Environment, Jean Baptiste Ndahetuye

Graduate Theses and Dissertations

Listeria monocytogenes an important foodborne pathogen that continues to be a serious problem for the food industry. This pathogen contaminates food primarily during post-harvest in the food-processing environment. Its ecology in the food-processing environment is not well understood but previous research has demonstrated the ability of L. monocytogenes to survive on food contact surfaces after cleaning and disinfection. The current study explored the attachment of three lactic acid bacteria (LAB) strains, Lactobacillus animalis , Lb. amylovorus and Pediococcus acidilactici , their combination in a cocktail, and their influence to prevent the attachment of L. monocytogenes at room temperature by examining …

Algae In Agricultural Fields From St. Francis County, Arkansas, T. Smith

Journal of the Arkansas Academy of Science

On August 9th, 2007, two agriculture fields (rice and sorghum fields) were sampled for freshwater algae in St. Francis County. The purpose of this study was to document the algal species in the rice and sorghum fields and compare the similarities of species composition. There were a total of 53 species identified. Overall, diatoms and cyanobacteria were equally dominant with both represented by 21 species (39.6% of the total) and 11 green algal species (20.8%) were present. The sorghum field was dominated by Chlorogloeopsis fritschii and Chroococcus limneticus, while Anabeana cylindrica was abundant in the rice field.

Characterization Of A PorosTm-Fumonisin B1 Affinity Column For Isolating Ceramide Synthase From Rat Liver, S. Jernigan, W. B. Melchior Jr., G. R. Jenkins, K. L. Rowland, D. W. Roberts, P. C. Howard, H. Tolleson

Journal of the Arkansas Academy of Science

Fumonisin B1 is a mycotoxin produced by fungi of the genus Fusarium, common pathogens of corn and other grain plants. Toxic effects associated with fumonisin B1 include equine leukoencephalomacia, porcine pulmonary edema, rat renal carcinoma, and murine hepatocellular carcinoma. Increased risk for esophageal cancer in humans has been epidemiologically associated with consumption of corn contaminated with Fusarium, suggesting that fumonisin B1 may be involved. The biological effects of fumonisin B1 exposure result primarily from disruption of de novo sphingolipid biosynthesis via inhibition of ceramide synthase. Exposure of animals or cultured cells to fumonisin B1 results in the characteristic accumulation of …

Microorganisms Associated With The Carapace And Plastron Of Aquatic Turtles (Pseudemys Concinna And Trachemys Scripta) In Southwestern Arkansas, Renn Tumlison, Sharon Clark

Journal of the Arkansas Academy of Science

No abstract provided.

Role Of Endophytes In Tall Fescue, E. L. Piper, C. P. West

Journal of the Arkansas Academy of Science

Tall fescue (Festuca arundinacea Schreb.) is the most commonly grown cool season grass used for pastures in Arkansas. Most tall fescue contains a fungal endophyte (Acremonium coenophialum Morgan-Jones & Gams), which causes fescue toxicosis in livestock and costs cattle producers millions of dollars annually in lost production. Endophyte presence is known to reduce wild mammal populations in areas where tall fescue is prevalent. The endophyte spends its entire life cycle within the plant and is transmitted through the seed. The association is mutualistic with the plant providing nutrients for the endophyte and the endophyte conferring drought, insect, and nematode resistance …

Evaluation Of Aposphaeria Amaranthi As A Bioherbicide For Pigweed (Amaranthus Spp.), A. S. Mintz, G. J. Weidmann

Journal of the Arkansas Academy of Science

Studies were conducted to determine the potential of the fungus, Aposphaeria amaranth!, as a bioherbicide for pigweeds (Amaranthus spp.). Experiments to establish the environmental parameters necessary for control of tumble pigweed (A. albus) demonstrated that an 8-hr dew period was sufficient for control of seedlings with four to six leaves, and that temperatures ranging from 20 to 28 C were conducive for disease development. Conidial concentrations as lowas 1x 10s conidia per ml also were sufficient for plant mortality. Host range tests demonstrated pathogenicity of A. amaranthi to several other species of Amaranthus, including biotypes resistant to triazine herbicides. Disease …

Development Of Pleurotus Ulmarius Fr. Grown In Pure Culture, Delbert Swartz, J. D. Collar

Journal of the Arkansas Academy of Science

No abstract provided.

Absence Of Pasteurella Pestis In The Wildlife Of Arkansas, R. Reece Corey, Leo J. Paulissen, Delbert Swartz

Journal of the Arkansas Academy of Science

No abstract provided.

Further Studies On An Antibiotic Substance Produced By Rhizopus Nigricans Ehrenberg, Kenneth D. Mace, Delbert Swartz

Journal of the Arkansas Academy of Science

No abstract provided.

List Of The Smut Fungi Of Arkansas, George E. Templeton

Journal of the Arkansas Academy of Science

No abstract provided.

Antibiotic Substance Produced By Rhizopus Nigricans Ehrenberg, Billy Joe Williams

Journal of the Arkansas Academy of Science

No abstract provided.