1,599 Matching Results

Search Results

Advanced search parameters have been applied.

The Rate of Natural Fermentation of Various Solutions with Regard to Temperature

Description: The purpose of this study is to investigate the rate of natural fermentation of solutions at different temperatures. Whatever microorganisms that chanced to be present in the air and that chanced to fall into the inoculating medium are the ones which brought about fermentation when transferred to the fermentable solution.
Date: August 1938
Creator: Lambert, Frank E.
Partner: UNT Libraries

Studies on Microorganisms in Jet Aircraft Fuel Systems

Description: Laboratory and field investigations during the past ten years have demonstrated that certain microorganisms can cause deleterious effects in jet fuel tank systems. These investigations have brought about new concepts concerning the mechanisms of utilization of certain constituents in jet fuel tanks by microorganisms. Since the presence of microorganisms is inevitable in fuel systems, research efforts have been directed towards identification and determination of the types of microorganisms which can utilize jet fuel hydrocarbons, fuel additives, polyurethane foam structural materials, and particular hydrocarbons present in the fuel.
Date: May 1970
Creator: Crum, Morris Glenn
Partner: UNT Libraries

Process Considerations in the Biodesulfurization of Crude Oil

Description: Biodesulfurization offers an attractive alternative to conventional hydrodesulfurization due to the mild operating conditions and reaction specificity afforded by the biocatalyst. The enzymatic pathway existing in Rhodococcus has been demonstrated to oxidatively desulfhrize the organic sulfbr occurring in dibenzothiophene while leaving the hydrocarbon intact. In order for biodesulfiization to realize commercial success, a variety of process considerations must be addressed including reaction rate, emulsion formation and breakage, biocatalyst recovery, and both gas and liquid mass transport. This study compares batch stirred to electro-spray bioreactors in the biodesulfurization of both model organics and actual crudes in terms of their operating costs, ability to make and break emulsions, ability to effect efficient reaction rates and enhance mass transport. Further, sulfim speciation in crude oil is assessed and compared to the sulfur specificity of currently available biocatalyst.
Date: October 20, 1998
Creator: Borole, A.P. & Kaufman, E.N.
Partner: UNT Libraries Government Documents Department

Travel grant program for the IX International Congresses of Mycology and Bacteriology -- Final report

Description: In 1999, the American Society for Microbiology (ASM) and the National Academy of Sciences' U.S. National Committee for the International Union of Microbiological Sciences (IUMS) jointly organized a competitive travel grant program to support the participation of U.S. scientists in the 9th International Congresses of the Bacteriological and Applied Microbiology, Mycology and Virology Divisions of the IUMS in Sydney, Australia, August 16-20, 1999. Funding was solicited for the program, and the ASM Minority and International Activities department administered the $40,000 raised. Travel grants in the amount of $2,000 were offered to U.S. investigators (citizens, including federal employees, and permanent residents working in the United States) in the early stages of their careers who planned to attend and present their research at the Congress. Teams of established and new investigators who applied jointly were eligible to received a combined $3,000 award. IUMS developed a questionnaire th at each applicant were required to complete and return, which asked each award recipient about their experience at the Congresses. Questionnaire results are included.
Date: May 25, 2000
Creator: Granigan, Marion
Partner: UNT Libraries Government Documents Department

Analysis of Illumina Microbial Assemblies

Description: Since the emerging of second generation sequencing technologies, the evaluation of different sequencing approaches and their assembly strategies for different types of genomes has become an important undertaken. Next generation sequencing technologies dramatically increase sequence throughput while decreasing cost, making them an attractive tool for whole genome shotgun sequencing. To compare different approaches for de-novo whole genome assembly, appropriate tools and a solid understanding of both quantity and quality of the underlying sequence data are crucial. Here, we performed an in-depth analysis of short-read Illumina sequence assembly strategies for bacterial and archaeal genomes. Different types of Illumina libraries as well as different trim parameters and assemblers were evaluated. Results of the comparative analysis and sequencing platforms will be presented. The goal of this analysis is to develop a cost-effective approach for the increased throughput of the generation of high quality microbial genomes.
Date: May 28, 2010
Creator: Clum, Alicia; Foster, Brian; Froula, Jeff; LaButti, Kurt; Sczyrba, Alex; Lapidus, Alla et al.
Partner: UNT Libraries Government Documents Department

Microorganisms Associated with a Spray Irrigation System

Description: The area of research for this thesis concerns the role played by microorganisms in the process of organic breakdown of waste effluent. Although considerable research has been done since the early 1950's, little consideration has been given to the role of the microorganisms in this type of waste water purification.
Date: August 1969
Creator: Nichols, Susan
Partner: UNT Libraries

Extensively Drug-Resistant Tuberculosis (XDR-TB): Emerging Public Health Threats and Quarantine and Isolation

Description: This report the international saga of Andrew Speaker, a traveler thought to have XDR-TB, a drug-resistant form of tuberculosis, placed a spotlight on existing mechanisms to contain contagious disease threats and raised numerous legal and public health issues. It also discusses the application of various public health measures available to contain an emerging public health threat posed by an individual who ignores medical advice and attempts to board an airplane or take other forms of public transportation.
Date: November 26, 2010
Creator: Swendiman, Kathleen S. & Jones, Nancy Lee
Partner: UNT Libraries Government Documents Department

Potential Trade Implications of Restrictions on Antimicrobial Use in Animal Production

Description: This report is organized into three parts. First, it provides an overview of U.S. export markets for livestock and poultry products, and highlights key U.S. foreign trading partners. Second, it discusses policies in selected foreign markets that may restrict or limit the use of antimicrobial drugs in food animal production, including imports of animal products grown with these drugs. Third, it discusses some implications of these policies for U.S. livestock and poultry exports to selected foreign markets.
Date: December 8, 2010
Creator: Johnson, Renée
Partner: UNT Libraries Government Documents Department

The Utilization of the Microflora Indigenous to and Present in Oil-Bearing Formations to Selectively Plug the More Porous Zones Thereby Increasing Oil Recovery During Waterflooding

Description: This project is a field demonstration of the ability of in-situ indigenous microorganisms in the North Blowhorn Creek Oil Field to reduce the flow of injection water in the more permeable zones of the reservoir, thereby diverting flow to other areas thus increasing the efficiency of the waterflood. The project is divided into three phases-Planning and Analysis (9 months), Implementation (45 months), and Technology Transfer (12 months). This report covers the fourth year of work on the project. During Phase I, cores were obtained from a newly drilled well and employed in laboratory core flood experiments to formulate the schedule and amounts of nutrients to be used in the field demonstration. The field demonstration involves injecting potassium nitrate, sodium dihydrogen phosphate, and in some cases molasses, into four injector wells (Test) and monitoring the performance of surrounding producer wells. For comparative purposes, the producer wells surrounding four untreated injector wells (Control) also were monitored. Twenty-two months after the injection of nutrients into the reservoir began, three wells were drilled and cores taken therefrom were analyzed. Nitrate ions were found in cores from all three wells and cores from two of these wells also contained phosphate ions- thus demonstrating that the injected nutrients were being distributed widely in the reservoir. Microorganisms were shown to be present in cores from all three wells by cultural methods and by electron microscopy. In some sections of the cores, the number of microbes was large. Oil production volumes and water:oil ratios (WOR) of produced fluids have shown clearly that the MEOR treatment being demonstrated in this project is improving oil recovery. Of the 15 producer wells in the test patterns, seven have responded positively to the injection of microbial nutrients into the reservoir, while all eight of the producer wells only in control patterns have ...
Date: January 1, 1998
Creator: Vadie, Alex A.; Stephens, James O. & Brown, Lewis R.
Partner: UNT Libraries Government Documents Department

Oral Microbiology

Description: Recent studies regarding research on oral microorganisms and the oral diseases are presented. The normal flora of the mouth and the oral environment are first described. Dental plaque and dental caries are primary causes of oral disease. Streptococcus mutans is the major contributor in the initiation and progression of dental caries. Lactobacillus, Actinomyces, and Veillonella are other genera of bacteria linked to dental caries. Periodontitis and gingivitis are periodontal diseases that are caused by oral microorganisms. New research has indicated that various antimicrobial agents and techniques to eliminate or lessen the severity of periodontal diseases. Premature delivery of low birth weight babies in pregnant women has been strongly linked to periodontal disease. Present and future microbiological tests are available to easily determine the causative organisms for most oral diseases that help in diagnosis and treatment of a particular disease.
Date: August 1998
Creator: Osman, Shaiesta
Partner: UNT Libraries

Manipulatiaon of Biofilm Microbial Ecology

Description: The Biofilm mode of growth provides such significant advantages to the members of the consortium that most organisms in important habitats are found in biofilms. The study of factors that allow manipulation of biofilm microbes in the biofilm growth state requires that reproducible biofilms by generated. The most effective monitoring of biofilm formation, succession and desquamation is with on-line monitoring of microbial biofilms with flowcell for direct observation. The biofilm growth state incorporates a second important factor, the heterogeneity in the distribution in time and space of the component members of the biofilm consortium. This heterogeneity is reflected not only in the cellular distribution but in the metabolic activity within a population of cells. Activity and cellular distribution can be mapped in four dimensions with confocal microscopy, and function can be ascertained by genetically manipulated reporter functions for specific genes or by vital stains. The methodology for understanding the microbial ecology of biofilms is now much more readily available and the capacity to manipulate biofilms is becoming an important feature of biotechnology.
Date: August 9, 1998
Creator: Burkhalter, R.; Macnaughton, S. J.; Palmer, R. J.; Smith, C. A.; Whitaker, K. W.; White, D. C. et al.
Partner: UNT Libraries Government Documents Department

Search for ancient microorganisms in Lake Baikal

Description: Lake Baikal in Russia, the world's oldest and deepest continental lake lies in south central Siberia, near the border to Mongolia. The lake is 1,643 m deep and has an area of about 46,000 km2. It holds one-fifth of all the terrestrial fresh water on Earth. Lake Baikal occupies the deepest portion of the Baikal Rift Zone. It was formed some 30-45 million years ago. The isolated Lake Baikal ecosystem represents a unique niche in nature based on its historical formation. The microbial diversity present in this environment has not yet been fully harvested or examined for products and processes of commercial interest and value. Thus, the collection of water, soil, and sub-bottom sediment samples was decided to characterize the microbial diversity of the isolated strains and to screen the isolates for their biotechnological value.
Date: June 14, 2000
Creator: Hunter-Cevera, Jennie C.; Repin, Vladimir E. & Torok, Tamas
Partner: UNT Libraries Government Documents Department

The Characterization of Psychrophilic Microorganisms and their potentially useful Cold-Active Glycosidases Final Progress Report

Description: Our studies of novel, cold-loving microorganisms have focused on two distinct extreme environments. The first is an ice core sample from a 120,000 year old Greenland glacier. The results of this study are particularly exciting and have been highlighted with press releases and additional coverage. The first press release in 2004 was based on our presentation at the General Meeting of the American Society for Microbiology and was augmented by coverage of our publication (Appl. Environ. Microbiol. 2005. Vol. 71:7806) in the Current Topics section of the ASM news journal, “Microbe.” Of special interest for this report was the isolation of numerous, phylogenetically distinct and potentially novel ultrasmall microorganisms. The detection and isolation of members of the ultrasmall population is significant because these cells pass through 0.2 micron pore filters that are generally used to trap microorganisms from environmental samples. Thus, analyses by other investigators that examined only cells captured on the filters would have missed a significant portion of this population. Only a few ultrasmall isolates had been obtained prior to our examination of the ice core samples. Our development of a filtration enrichment and subsequent cultivation of these organisms has added extensively to the collection of, and knowledge about, this important population in the microbial world.
Date: June 30, 2008
Creator: Brenchly, Jean E.
Partner: UNT Libraries Government Documents Department

Polypeptide and Polysaccharide Processing in Hyperthermophilic Microorganisms

Description: This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.
Date: December 22, 2008
Creator: Kelly, Robert M.
Partner: UNT Libraries Government Documents Department

Microarray-based analysis of survival of soil microbial community during ozonation

Description: A 15 h ozonation was performed on bioremediated soil to remove recalcitrant residual oil. To monitor the survival of indigenous microorganisms in the soil during in-situ chemical oxidation(ISCO) culturing and a functional genearray, GeoChip, was used to examine the functional genes and structure of the microbial community during ozonation (0h, 2h, 4h, 6h, 10hand15h). Breakthrough ozonation decreased the population of cultivable heterotrophic bacteria by about 3 orders of magnitude. The total functional gene abundance and diversity decreased during ozonation, as the number of functional genes was reduced by 48percent after 15 h. However, functional genes were evenly distributed during ozonation as judged by the Shannon-Weaver Evenness index. A sharp decrease in gene number was observed in the first 6 h of ozonation followed by a slower decrease in the next 9 h, which was consistent with microbial populations measured by a culture based method. Functional genes involved in carbon, nitrogen, phosphors and sulfur cycling, metal resistance and organic remediation were detected in all samples. Though the pattern of gene categories detected was similar for all time points, hierarchica lcluster of all functional genes and major functional categories all showed a time-serial pattern. Bacteria, archaea and fungi decreased by 96.1percent, 95.1percent and 91.3percent, respectively, after 15 h ozonation. Delta proteobacteria, which were reduced by 94.3percent, showed the highest resistance to ozonation while Actinobacteria, reduced by 96.3percent, showed the lowest resistance. Microorganisms similar to Rhodothermus, Obesumbacterium, Staphylothermus, Gluconobacter, and Enterococcus were dominant at all time points. Functional genes related to petroleum degradation decreased 1~;;2 orders of magnitude. Most of the key functional genes were still detected after ozonation, allowing a rapid recovery of the microbial community after ozonation. While ozone had a large impact on the indigenous soil microorganisms, a fraction of the key functional gene-containing microorganisms survived during ozonation and kept ...
Date: May 17, 2010
Creator: Wang, Jian; Van Nostrand, Joy D.; He, Zhili; Wu, Liyou; Deng, Ye; Zhang, Xu et al.
Partner: UNT Libraries Government Documents Department

TOUGH+/GasH20 study of the effects of a heat source buried in theMartian permafrost

Description: We use TOUGH+/GasH2O to study the effects of a heat sourceburied in the Martian permafrost to evaluate the possibility ofestablishing a wet zone of liquid water, in which terrestrialmicroorganisms could survive and multiply. Analysis of the problemindicates that (1) only a limited permafrost volume (not exceeding 0.35 min radius) is affected, (2) a "wet" zone with limited amounts of liquidwater de-velops (not exceeding 8 and 0.7 kg for a 250 W and a 62.5 Wsource, respectively), (3) the wet zone per-sists for a long time,becomes practically stationary after t = 20 sols because of venting intothe Martian atmosphere, and its thickness is limited and decreases slowlyover time, (4) a "dry" zone (where SG>0.9) evolves, continues toexpand (albeit slowly) with time, but its extent remains limited, and (5)the ice front surrounding the wet zone is self-sharpening. For a range ofinitial conditions investigated, evolution of the liquid water massoccurs at approximately the same rate, reaches roughly the same maximum,and occurs at about the same time (10 to 20 sols; 1 sol = 24.39hours).
Date: May 12, 2006
Creator: Moridis, George J. & Pruess, Karsten
Partner: UNT Libraries Government Documents Department

The Nonphotosynthetic Fixation of Carbon Dioxide by ThreeMicro-Organisms

Description: Studies by Lynch and Calvin (1952,1953) have established the nature of the compounds incorporating C{sup 14} nonphotosynthetically from C{sup 14}O{sub 2} in thirteen microorganisms: a yeast, a protozoan, two water moulds, one slime mould, three algae, three bacteria, and the green flagellate Euglena Gracilis. With the exception of H. gracilis, and of Lactobacillus cassi which fixed no detectable amounts of carbon dioxide, all these organisms fixed carbon dioxide into amino and organic acids derived from the tricarboxylic acid cycle, and into a few other compounds in individual cases (tyrosine, phenylalanine, polysaccharides [probably glucose polymers], acetic acid and butyric acid). The authors concluded that the presence of C{sup 14} in almost all these compounds could be accounted for by the carboxylation of pyruvate to yield oxalacetic or malic acids, followed by transaminase reactions. In E. gracilis, however, considerable quantities of activity also appeared in phosphorylated compounds in the dark, especially in the sugar monophosphates, phosphoglyceric acid, and phosphoenolpyruvic acid. Only with this organisms was a kinetic study performed to determine the identity and degree of labeling of the compounds containing C{sup 14} after varying periods of time. It was not stated definitely by which route carbon dioxide entered the photosynthetic intermediates, but it was implied that it was incorporated directly into phosphoglyceric acid, and that the energy for this process, which in photosynthesis is derived from sunlight, and was provided by respiration or fermentation. Certain aspects of these presumptions however, do not adequately account for all the experimental data.
Date: July 1, 1958
Creator: Holm-Hansen, O.; Moses, V. & Calvin, M.
Partner: UNT Libraries Government Documents Department

Expansion of the Genomic Encyclopedia of Bacteria and Archaea

Description: To date the vast majority of bacterial and archaeal genomes sequenced are of rather limited phylogenetic diversity as they were chosen based on their physiology and/ or medical importance. The Genomic Encyclopedia of Bacteria and Archaea (GEBA) project (Wu et al. 2009) is aimed to systematically filling the gaps of the tree of life with phylogenetically diverse reference genomes. However more than 99percent of microorganisms elude current culturing attempts, severely limiting the ability to recover complete or even partial genomes of these largely mysterious species. These limitations gave rise to the GEBA uncultured project. Here we propose to use single cell genomics to massively expand the Genomic Encyclopedia of Bacteria and Archaea by targeting 80 single cell representatives of uncultured candidate phyla which have no or very few cultured representatives. Generating these reference genomes of uncultured microbes will dramatically increase the discovery rate of novel protein families and biological functions, shed light on the numerous underrepresented phyla that likely play important roles in the environment, and will assist in improving the reconstruction of the evolutionary history of Bacteria and Archaea. Moreover, these data will improve our ability to interpret metagenomics sequence data from diverse environments, which will be of tremendous value for microbial ecology and evolutionary studies to come.
Date: March 20, 2011
Creator: Rinke, Christian; Sczyrba, Alex; Malfatti, Stephanie; Lee, Janye; Cheng, Jan-Fang; Stepanauskas, Ramunas et al.
Partner: UNT Libraries Government Documents Department