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Energy transfer mechanisms in photobiological reactions. Progress report, 1 August 1976--31 July 1977

Description: Progress is reported on the following studies: chemical structure of biomolecules and mechanisms of their sensitized photo-oxidation; relationships between the structure and photosensitizing efficiencies of porphyrins; effects of photodynamic treatment on mammalian tendons; and sensitized photo-oxidation of substituted uracils, methionine, other amino acids, and horse-radish peroxidase. (HLW)
Date: July 31, 1977
Creator: Spikes, J. D.
Partner: UNT Libraries Government Documents Department
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Energy transfer mechanisms in photobiological reactions. Progress report, 1 August 1975--30 April 1976

Description: As in our earlier work on the sensitized photooxidation of substituted phenylalanines, ring substituents were found to have a marked effect on the photooxidation of uracil. This compound was selected as a typical pyrimidine for detailed studies of the mechanism of photooxidation of molecules of biological importance. The photooxidation of a series of 5-substituted uracils as sensitized by eosin Y, ruthenium bipyridyl, 3-methyl-lumiflavin and methylene blue was studied using oxygen electrode and… more
Date: April 30, 1976
Creator: Spikes, J. D.
Partner: UNT Libraries Government Documents Department
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(Physiology and molecular biology of extracellular peroxidases, H sub 2 O sub 2 -generating system and deregulated mutants of Phanerochaete chrysosporium)

Description: We have expanded the work on the LIP genes to Trametes versicolor, the second most studied white-rot fungus after P. chrysosporium. Six LIP genes have been cloned from this organism and one of these has been completely sequenced and compared to the known LIP genes that have been described to date. Our studies gave us further insights into the novel non-integrative transformation system of P. chrysosporium. Our recombinant plasmid pUGLGl-kan, which contains a LIP gene disrupted by the insertion … more
Date: January 1, 1992
Partner: UNT Libraries Government Documents Department
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Applications of Micellar Enzymology to Clean Coal Technology. Tenth Quarterly Report

Description: Full implementation of coal fuel sources will require more effective methods of providing ``clean coal`` as a fuel source. Methods must be developed to reduce the sulfur content of coal which significantly contributes to environmental pollution. This project is designed to develop methods for pre-combustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic … more
Date: April 29, 1992
Creator: Walsh, C. T.
Partner: UNT Libraries Government Documents Department
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Phanerochaete mutants with enhanced ligninolytic activity

Description: In addition to lignin, the white rot fungus Phanerochaete chrysosporium has the ability to degrade a wide spectrum of recalcitrant organopollutants in soils and aqueous media. Although some of the organic compounds are degraded under nonligninolytic conditions, most are degraded under ligninolytic conditions with the involvement of the extracellular enzymes, lignin peroxidases, and manganese-dependent peroxidases, which are produced as secondary metabolites triggered by conditions of nutrient s… more
Date: June 1, 1993
Creator: Kakar, S. N.; Perez, A. & Gonzales, J.
Partner: UNT Libraries Government Documents Department
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[Physiology and molecular biology of extracellular peroxidases, H{sub 2}O{sub 2}-generating system and deregulated mutants of Phanerochaete chrysosporium]. Progress report

Description: We have expanded the work on the LIP genes to Trametes versicolor, the second most studied white-rot fungus after P. chrysosporium. Six LIP genes have been cloned from this organism and one of these has been completely sequenced and compared to the known LIP genes that have been described to date. Our studies gave us further insights into the novel non-integrative transformation system of P. chrysosporium. Our recombinant plasmid pUGLGl-kan, which contains a LIP gene disrupted by the insertion … more
Date: July 1, 1992
Partner: UNT Libraries Government Documents Department
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Genetics and chemistry of lignin degradation by Streptomyces. Final technical report

Description: Our research goal was to define the involvement of lignin peroxidases and other extracellular enzymes in lignin degradation by Streptomyces. We examined the biochemistry and genetics of lignin degrading enzyme production by several strains of Streptomyces. The lignin peroxidase ALiP-P3 of S. viridosporus was characterized kinetically and its activity optimized for oxidation of 2,4-dichlorophenol and vanillyl-acetone. Sensitive spectrophotometric assays were developed for monitoring oxidation of… more
Date: December 31, 1992
Creator: Crawford, D. L.
Partner: UNT Libraries Government Documents Department
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The molecular characterization of the lignin-forming peroxidase. Progress summary report, April 1, 1989--March 31, 1992

Description: This laboratory is committed to understanding the function of plant peroxidases via a multi-disciplinary approach. We have chosen the lignin-forming peroxidase from tobacco as the first isoenzyme to be subjected to this comprehensive approach. The goals which were set out upon the initiation of this project were as follows: (1) utilize a cDNA clone to the tobacco anionic peroxidase to generate transgenic plants which either over-produced this isoenzyme or specifically under-produced this isoenz… more
Date: April 1, 1992
Creator: Lagrimini, L. M.
Partner: UNT Libraries Government Documents Department
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Molecular characterization of the lignin-forming peroxidase: Role in growth, development and response to stress. Progress summary report, April 1, 1993--March 31, 1994

Description: Our group continues to focus on the characterization of the tobacco anionic peroxidase and its genes. Throughout this past year we have generated transgenic plants expressing {beta}-glucuronidase under control of the anionic peroxidase promoter, characterized effectors of peroxidase gene expression in transformed protoplasts, generated numerous transgenic plants which over- and under-express the anionic peroxidase in a tissue specific manner, characterized the role of the anionic peroxidase in … more
Date: May 1, 1994
Creator: Lagrimini, L. M.
Partner: UNT Libraries Government Documents Department
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Molecular characterization of the lignin-forming peroxidase: Role in growth, development and response to stress. Progress summary report, April 1, 1992--March 31, 1993

Description: This laboratory has continued its comprehensive study of the structure and function of plant peroxidases and their genes. Specifically, we are characterizing the anionic peroxidase of tobacco. During the past year we have completed the nucleotide sequence of the tobacco anionic peroxidase gene, joined the anionic peroxidase promoter to {Beta}-glucuronidase and demonstrated expression in transformed plants, measured lignin, auxin, and ethylene levels in transgenic tobacco plants over-expressing … more
Date: March 1, 1993
Creator: Lagrimini, L. M.
Partner: UNT Libraries Government Documents Department
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Altered phenotypes in plants transformed with chimeric tobacco peroxidase genes

Description: Peroxidases have been implicated in a variety of secondary metabolic reactions including lignification, cross-linking of cell wall polysaccharides, oxidation of indole-3-acetic acid, regulation of cell elongation, wound-healing, phenol oxidation, and pathogen defense. However, due to the many different isoenzymes and even more potential substrates, it has proven difficult to verify actual physiological roles for peroxidase. We are studying the molecular biology of the tobacco peroxidase genes, … more
Date: December 31, 1990
Creator: Lagrimini, L. M.
Partner: UNT Libraries Government Documents Department
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Enzymatic desulfurization of coal. First quarterly report, May 5--September 30, 1988

Description: Our current efforts to develop clean coal technology, emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of ``model`` organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated or… more
Date: October 7, 1988
Creator: Marquis, J. K. & Kitchell, J. P.
Partner: UNT Libraries Government Documents Department
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Enzymatic desulfurization of coal. Second quarterly report, October 1--December 15, 1988

Description: Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of ``model`` organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated org… more
Date: December 15, 1988
Creator: Marquis, J. K. & Kitchell, J. P.
Partner: UNT Libraries Government Documents Department
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Enzymatic desulfurization of coal. Sixth quarterly report, September 16--December 15, 1989

Description: Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds., In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanie… more
Date: December 14, 1989
Creator: Boyer, Y. N.; Crooker, S. C.; Kitchell, J. P. & Nochur, S. V.
Partner: UNT Libraries Government Documents Department
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[Characterization of lignin and Mn peroxidases from Phanerochaete chrysosporium]. Progress report

Description: Lignin peroxidases were investigated with respect to enzyme kinetics and NMR spectroscopy of the heme domain. MN peroxidases were studied with respect to the role of oxalate in enzyme activity, the NMR spectroscopy of the heme domain. Gene expression of both lignin and MN peroxidases were examined as well as expression of site-directed mutants aimed at scale up production of these enzymes.
Date: December 31, 1992
Partner: UNT Libraries Government Documents Department
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Characterization of lignin and Mn peroxidases from Phanerochaete chrysosporium. Progress report

Description: Long-term objectives are to elucidate the role and mechanism of the various isozymes in lignin biodegradation. Work is described on electrochemical studies on lignin and Mn peroxidases. This study was performed to investigate the structural aspects which confer the lignin and Mn peroxidases with their high reactivity. The experimentally determined redox potential of the Fe{sup 3+}/Fe{sup 2+} couple for the lignin peroxidase isozymes H1, H2, H8 and H10 are very similar, near-130 mV. The redox po… more
Date: December 31, 1991
Partner: UNT Libraries Government Documents Department
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Enzymatic desulfurization of coal. Seventh quarterly report, December 16, 1989--March 15, 1990

Description: Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds. In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanied… more
Date: March 23, 1990
Creator: Boyer, Y. N.; Crooker, S. C.; Kitchell, J. P. & Nochur, S. V.
Partner: UNT Libraries Government Documents Department
open access

Unravelling lignin formation and structure. Final report, April 1, 1988--March 31, 1991

Description: During this study, we established that the Fagaceae exclusively accumulate Z-monolignois/glucosides, and not the E-isomers. Evidence for the presence of a novel E{yields}Z isomerse has been obtained. Our pioneering work in lignin biosynthesis and structure in situ has also progressed smoothly. We established the bonding environments of a woody angiosperm, Leucanea leucocephala, as well as wheat (T. aestivum) and tobacco (N. tabacum). A cell culture system from Pinus taeda was developed which se… more
Date: December 31, 1991
Creator: Lewis, N. G.
Partner: UNT Libraries Government Documents Department
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Enzymatic desulfurization of coal. Fourth quarterly report, March 16--June 15, 1989

Description: Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes as well as commercially available enzymes. Our work is focused on the treatment of ``model`` organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydr… more
Date: June 16, 1989
Creator: Boyer, Y. N.; Crooker, S. C.; Kitchell, J. P.; Nochur, S. V. & Marquis, J. K.
Partner: UNT Libraries Government Documents Department
open access

Enzymatic desulfurization of coal. Fifth quarterly report, June 16--September 15, 1989

Description: Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds. In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanied… more
Date: November 7, 1989
Creator: Boyer, Y. N.; Crooker, S. C.; Kitchell, J. P.; Nochur, S. V. & Marquis, J. K.
Partner: UNT Libraries Government Documents Department
open access

Genetics and chemistry of lignin degradation by Streptomyces

Description: Our research goal was to define the involvement of lignin peroxidases and other extracellular enzymes in lignin degradation by Streptomyces. We examined the biochemistry and genetics of lignin degrading enzyme production by several strains of Streptomyces. The lignin peroxidase ALiP-P3 of S. viridosporus was characterized kinetically and its activity optimized for oxidation of 2,4-dichlorophenol and vanillyl-acetone. Sensitive spectrophotometric assays were developed for monitoring oxidation of… more
Date: January 1, 1992
Creator: Crawford, D.L.
Partner: UNT Libraries Government Documents Department
open access

[Characterization of lignin and Mn peroxidases from Phanerochaete chrysosporium]

Description: Lignin peroxidases were investigated with respect to enzyme kinetics and NMR spectroscopy of the heme domain. MN peroxidases were studied with respect to the role of oxalate in enzyme activity, the NMR spectroscopy of the heme domain. Gene expression of both lignin and MN peroxidases were examined as well as expression of site-directed mutants aimed at scale up production of these enzymes.
Date: January 1, 1992
Partner: UNT Libraries Government Documents Department
open access

Molecular characterization of the lignin-forming peroxidase: Role in growth, development and response to stress

Description: This laboratory has continued its comprehensive study of the structure and function of plant peroxidases and their genes. Specifically, we are characterizing the anionic peroxidase of tobacco. During the past year we have completed the nucleotide sequence of the tobacco anionic peroxidase gene, joined the anionic peroxidase promoter to [Beta]-glucuronidase and demonstrated expression in transformed plants, measured lignin, auxin, and ethylene levels in transgenic tobacco plants over-expressing … more
Date: January 1, 1993
Creator: Lagrimini, L.M.
Partner: UNT Libraries Government Documents Department
open access

Enzymatic desulfurization of coal

Description: Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds., In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanie… more
Date: December 14, 1989
Creator: Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P. & Nochur, S.V.
Partner: UNT Libraries Government Documents Department
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