14 Matching Results

Search Results

Interspecific Comparison and annotation of two complete mitochondrial genome sequences from the plant pathogenic fungus Mycosphaerella graminicola

Description: The mitochondrial genomes of two isolates of the wheat pathogen Mycosphaerella graminicola were sequenced completely and compared to identify polymorphic regions. This organism is of interest because it is phylogenetically distant from other fungi with sequenced mitochondrial genomes and it has shown discordant patterns of nuclear and mitochondrial diversity. The mitochondrial genome of M. graminicola is a circular molecule of approximately 43,960 bp containing the typical genes coding for 14 proteins related to oxidative phosphorylation, one RNA polymerase, two rRNA genes and a set of 27 tRNAs. The mitochondrial DNA of M. graminicola lacks the gene encoding the putative ribosomal protein (rps5-like), commonly found in fungal mitochondrial genomes. Most of the tRNA genes were clustered with a gene order conserved with many other ascomycetes. A sample of thirty-five additional strains representing the known global mt diversity was partially sequenced to measure overall mitochondrial variability within the species. Little variation was found, confirming previous RFLP-based findings of low mitochondrial diversity. The mitochondrial sequence of M. graminicola is the first reported from the family Mycosphaerellaceae or the order Capnodiales. The sequence also provides a tool to better understand the development of fungicide resistance and the conflicting pattern of high nuclear and low mitochondrial diversity in global populations of this fungus.
Date: December 7, 2007
Creator: Millenbaugh, Bonnie A; Pangilinan, Jasmyn L.; Torriani, Stefano F.F.; Goodwin, Stephen B.; Kema, Gert H.J. & McDonald, Bruce A.
Partner: UNT Libraries Government Documents Department

Selecting an Algicide for Use with Aluminum Alloys

Description: This paper discusses the testing and results of five relatively noncorrosive commercially available compounds compared with one another and with sodium hypochlorite for their potential applicability as algicides in water systems containing aluminum alloys.
Date: March 15, 2001
Creator: Wilde, E.W.
Partner: UNT Libraries Government Documents Department

The biofilm ecology of microbial biofouling, biocide resistance and corrosion

Description: In biotechnological or bioremediation processes it is often the aim to promote biofilm formation, and maintain active, high density biomass. In other situations, biofouling can seriously restrict effective heat transport, membrane processes, and potentate macrofouling with loss of transportation efficiency. In biotechnological or bioremediation processes it is often the aim to promote biofilm formation, and maintain active, high density biomass. In other situations, biofouling can seriously restrict effective heat transport, membrane processes, and potentate macrofouling with loss of transportation efficiency. Heterogeneous distribution of microbes and/or their metabolic activity can promote microbially influenced corrosion (MIC) which is a multibillion dollar problem. Consequently, it is important that biofilm microbial ecology be understood so it can be manipulated rationally. It is usually simple to select organisms that form biofilms by flowing a considerably dilute media over a substratum, and propagating the organisms that attach. To examine the biofilm most expeditiously, the biomass accumulation, desquamation, and metabolic activities need to be monitored on-line and non-destructively. This on-line monitoring becomes even more valuable if the activities can be locally mapped in time and space within the biofilm. Herein the authors describe quantitative measures of microbial biofouling, the ecology of pathogens in drinking water distributions systems, and localization of microbial biofilms and activities with localized MIC.
Date: June 1, 1997
Creator: White, D.C.; Kirkegaard, R.D.; Palmer, R.J. Jr.; Flemming, C.A.; Chen, G.; Leung, K.T. et al.
Partner: UNT Libraries Government Documents Department

Biocide usage in cooling towers in the electric power and petroleum refining industries

Description: Cooling towers users frequently apply biocides to the circulating cooling water to control growth of microorganisms, algae, and macroorganisms. Because of the toxic properties of biocides, there is a potential for the regulatory controls on their use and discharge to become increasingly more stringent. This report examines the types of biocides used in cooling towers by companies in the electric power and petroleum refining industries, and the experiences those companies have had in dealing with agencies that regulate cooling tower blowdown discharges. Results from a sample of 67 electric power plants indicate that the use of oxidizing biocides (particularly chlorine) is favored. Quaternary ammonia salts (quats), a type of nonoxidizing biocide, are also used in many power plant cooling towers. The experience of dealing with regulators to obtain approval to discharge biocides differs significantly between the two industries. In the electric power industry, discharges of any new biocide typically must be approved in writing by the regulatory agency. The approval process for refineries is less formal. In most cases, the refinery must notify the regulatory agency that it is planning to use a new biocide, but the refinery does not need to get written approval before using it. The conclusion of the report is that few of the surveyed facilities are having any difficulty in using and discharging the biocides they want to use.
Date: November 1, 1997
Creator: Veil, J.; Rice, J.K. & Raivel, M.E.S.
Partner: UNT Libraries Government Documents Department

Catalytic photooxidation of pentachlorophenol using semiconductor nanoclusters

Description: Pentachlorophenol (PCP) is a toxic chlorinated aromatic molecule widely used as fungicide, a bactericide and a wood preservation, and thus ubiquitous in the environment. The authors report photo-oxidation of PCP using a variety of nanosize semiconductor metal oxides and sulfides in both aqueous and polar organic solvents and compare the photo-oxidation kinetics of these nanoclusters to widely studied bulk powders like Degussa P-25 TiO{sub 2} and CdS. They study both the light intensity dependence of PCP photooxidation for nanosize SnO{sub 2} and the size dependence of PCP photooxidation for both nanosize SnO{sub 2} and MoS{sub 2}. They find an extremely strong size dependence for the latter which they attribute to its size-dependent band gap and the associated change in redox potentials due to quantum confinement of the hole-electron pair. The authors show that nanosize MoS{sub 2} with a diameter of d=3.0 nm and an absorbance edge of {approximately}450 nm is a very effective photooxidation catalyst for complete PCP mineralization, even when using only visible light irradiation.
Date: April 17, 2000
Partner: UNT Libraries Government Documents Department

Rationale for Selection of Pesticides, Herbicides, and Related Compounds from the Hanford SST/DST Waste Considered for Analysis in Support of the Regulatory DQO (Privatization)

Description: Regulated pesticides, herbicides, miticides, and fungicides were evaluated for their potential past and current use at the Hanford Site. The starting list of these compounds is based on regulatory analyte input lists discussed in the Regulatory DQO. Twelve pesticide, herbicide, miticide, and fungicide compounds are identified for analysis in the Hanford SST and DST waste in support of the Regulatory DQO. The compounds considered for additional analyses are non-detected, considered stable in the tank waste matrix, and of higher toxicity/carcinogenicity.
Date: January 4, 1999
Creator: Wiemers, K.D.; Daling, P. & Meier, K.
Partner: UNT Libraries Government Documents Department

Asian Soybean Rust: Background and Issues

Description: This report discusses the background and issues regarding Asian soybean rust (ASR) that was discovered in the United States in an experimental field in Louisiana. The U.S. Department of Agriculture (USDA) is coordinating a plan to deal with ASR that encompasses various USDA agencies, state land-grant universities, and industry participants. The arrival of ASR has implications for several public policies including pest control research (particularly the development of resistant varieties), pesticide regulation, disaster assistance, and crop insurance.
Date: January 12, 2005
Creator: Schnepf, Randy
Partner: UNT Libraries Government Documents Department

Research to Identify Effective Antifungal Agents, 1990 Annual Report.

Description: The objectives of the present contract study were to select and evaluate up to 10 candidate fungicides. Evaluations of Goal 1 involve laboratory studies on efficacy of candidate compounds on cultured Saprolegniales, and on eggs of rainbow trout and chinook salmon that were previously infected with the fungus. The main objective this year of Goal 2 was to determine the degree of fungal infection in untreated, control fish to establish the extent of the problem.
Date: July 1, 1990
Creator: Schreck, Carl
Partner: UNT Libraries Government Documents Department

Pesticide Use and Water Quality: Are the Laws Complementary or in Conflict?

Description: This report provides background on the conflict over interpretation and implementation of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Clean Water Act. A brief discussion of the two laws is followed by a review of the major litigation of interest. EPA's efforts to clarify its policy in this area and the November 2006 rule and the 2009 federal court ruling are discussed, as well as possible options for EPA and Congress to further address the FIFRA-CWA issues. In June, EPA proposed a draft general CWA permit that it intends to finalize by April 2011 in response to the court ruling.
Date: October 13, 2010
Creator: Copeland, Claudia
Partner: UNT Libraries Government Documents Department

Enzymantic Conversion of Coal to Liquid Fuels

Description: The work in this project focused on the conversion of bituminous coal to liquid hydrocarbons. The major steps in this process include mechanical pretreatment, chemical pretreatment, and finally solubilization and conversion of coal to liquid hydrocarbons. Two different types of mechanical pretreatment were considered for the process: hammer mill grinding and jet mill grinding. After research and experimentation, it was decided to use jet mill grinding, which allows for coal to be ground down to particle sizes of 5 {mu}m or less. A Fluid Energy Model 0101 JET-O-MIZER-630 size reduction mill was purchased for this purpose. This machine was completed and final testing was performed on the machine at the Fluid Energy facilities in Telford, PA. The test results from the machine show that it can indeed perform to the required specifications and is able to grind coal down to a mean particle size that is ideal for experimentation. Solubilization and conversion experiments were performed on various pretreated coal samples using 3 different approaches: (1) enzymatic - using extracellular Laccase and Manganese Peroxidase (MnP), (2) chemical - using Ammonium Tartrate and Manganese Peroxidase, and (3) enzymatic - using the live organisms Phanerochaete chrysosporium. Spectral analysis was used to determine how effective each of these methods were in decomposing bituminous coal. After analysis of the results and other considerations, such as cost and environmental impacts, it was determined that the enzymatic approaches, as opposed to the chemical approaches using chelators, were more effective in decomposing coal. The results from the laccase/MnP experiments and Phanerochaete chrysosporium experiments are presented and compared in this final report. Spectra from both enzymatic methods show absorption peaks in the 240nm to 300nm region. These peaks correspond to aromatic intermediates formed when breaking down the coal structure. The peaks then decrease in absorbance over time, corresponding to ...
Date: January 31, 2011
Creator: Troiano, Richard
Partner: UNT Libraries Government Documents Department

Transcriptomic response of the mycoparasitic fungus Trichoderma atroviride to the presence of a fungal prey

Description: BACKGROUND: Combating the action of plant pathogenic microorganisms by mycoparasitic fungi has been announced as an attractive biological alternative to the use of chemical fungicides since two decades. The fungal genus Trichoderma includes a high number of taxa which are able to recognize, combat and finally besiege and kill their prey. Only fragments of the biochemical processes related to this ability have been uncovered so far, however. RESULTS: We analyzed genome-wide gene expression changes during the begin of physical contact between Trichoderma atroviride and two plant pathogens Botrytis cinerea and Rhizoctonia solani, and compared with gene expression patterns of mycelial and conidiating cultures, respectively. About 3000 ESTs, representing about 900 genes, were obtained from each of these three growth conditions. 66 genes, represented by 442 ESTs, were specifically and significantly overexpressed during onset of mycoparasitism, and the expression of a subset thereof was verified by expression analysis. The upregulated genes comprised 18 KOG groups, but were most abundant from the groups representing posttranslational processing, and amino acid metabolism, and included components of the stress response, reaction to nitrogen shortage, signal transduction and lipid catabolism. Metabolic network analysis confirmed the upregulation of the genes for amino acid biosynthesis and of those involved in the catabolism of lipids and aminosugars. CONCLUSION: The analysis of the genes overexpressed during the onset of mycoparasitism in T. atroviride has revealed that the fungus reacts to this condition with several previously undetected physiological reactions. These data enable a new and more comprehensive interpretation of the physiology of mycoparasitism, and will aid in the selection of traits for improvement of biocontrol strains by recombinant techniques.
Date: July 23, 2010
Creator: Seidl, Verena; Song, Lifu; Lindquist, Erika; Gruber, Sabine; Koptchinskiy, Alexeji; Zeilinger, Susanne et al.
Partner: UNT Libraries Government Documents Department