Hydrogenase
Mostrando 1-12 de 468 artigos, teses e dissertações.
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1. Eficiencia simbiotica de estirpes HUP+, HUPhr e HUP. de bradyrhizobium japonicum e bradyrhizobium elkanii em cultivares de caupi.
A eficiencia das estirpes de Bradyrhizobium com caracteristicas Hup+ (SR e USDA-110), Hup. (29W) e Hup hr (SEMIA-587) foi avaliada em caupi (Vigna unguiculata L.), cultivares IPA-202, BR-3 e VITA-4. Os resultados mostraram que VITA-4, em relacao a nodulacao, revelou-se superior as demais, e apresentou interacao efetiva com as estirpes SEMIA-587 e USDA-110. E
Pesquisa Agropecuaria Brasileira. Publicado em: 2011
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2. ASPECTOS FISIOLÃGICOS E BIOQUÃMICOS DA MATURAÃÃO DE SEMENTES DE PIMENTÃO. / Physiological and biochemical aspects of the maturation of sweet pepper seeds
The determination of the appropriate point or interval for the harvest of fruits for sweet pepper seed production is fundamental for success in production programming, as well as for obtaining quality seeds. From their physiological maturity period up to the moment they are used for sowing, the seeds are subject to loss of physiological quality due to the oc
Publicado em: 2009
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3. TEMPERATURE-SENSITIVE HYDROGENASE AND HYDROGENASE SYNTHESIS IN A PSYCHROPHILIC BACTERIUM
Upadhyay, J. (Washington State University, Pullman) and J. L. Stokes. Temperature-sensitive hydrogenase and hydrogenase synthesis in a psychrophilic bacterium. J. Bacteriol. 86:992–998. 1963.—Hydrogenase and its synthesis were more heat-sensitive in psychrophilic strain 82 than in mesophilic Escherichia coli. The enzyme was not formed above 20 C by the p
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4. Regulation by molecular oxygen and organic substrates of hydrogenase synthesis in Alcaligenes eutrophus.
Chemoautotrophic growth of Alcaligenes eutrophus 17707 is inhibited by 20% oxygen in the gas phase. Lowering the oxygen concentration to 4% results in chloramphenicol-sensitive derepression of soluble and membrane-bound hydrogenase activity (and of soluble hydrogenase antigen), showing that oxygen inhibition is due at least in part to repression of hydrogena
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5. A genetic region downstream of the hydrogenase structural genes of Bradyrhizobium japonicum that is required for hydrogenase processing.
Deletion of a 2.9-kb chromosomal EcoRI fragment of DNA located 2.2 kb downstream from the end of the hydrogenase structural genes resulted in the complete loss of hydrogenase activity. The normal 65- and 35-kDa hydrogenase subunits were absent in the deletion mutants. Instead, two peptides of 66.5 and 41 kDa were identified in the mutants by use of anti-hydr
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6. Hydrogenase activity in Rhodopseudomonas capsulata: relationship with nitrogenase activity.
Hydrogenase activity was found in cells of Rhodopseudomonas capsulata strain B10 cultured under a variety of growth conditions either anaerobically in the light or aerobically in the dark. The highest activities were found routinely in cells grown in the presence of H2. The hydrogenase of R. capsulata was localized in the particulate fraction of the cells. H
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7. Regulation of hydrogenase activity in enterobacteria.
Proteus vulgaris, Escherichia coli, and Citrobacter freundii cells were devoid of hydrogenase activity when grown on complex medium or minimal medium plus glucose in the presence of saturating levels of dissolved oxygen. Anaerobically grown cells had appreciable hydrogenase activity. Cells grown anaerobically in the presence of CO (an inhibitor of hydrogenas
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8. Comparative characterization of two distinct hydrogenases from Anabaena sp. strain 7120.
Two distinct hydrogenases, hereafter referred to as "uptake" and "reversible" hydrogenase, were extracted from Anabaena sp. strain 7120 and partially purified. The properties of the two enzymes were compared in cell-free extracts. Uptake hydrogenase was largely particulate, and although membrane bound, it could catalyze an oxyhydrogen reaction. Particulate a
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9. Regulation of hydrogenase in Rhizobium japonicum.
Factors that regulate the expression of an H2 uptake system in free-living cultures of Rhizobium japonicum have been investigated. Rapid rates of H2 uptake by R. japonicum were obtained by incubation of cell suspensions in a Mg-phosphate buffer under a gas phase of 86.7% N2, 8.3% H2, 4.2% CO2, and 0.8% O2. Cultures incubated under conditions comparable with
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10. Characterization and physiological roles of membrane-bound hydrogenase isoenzymes from Salmonella typhimurium.
We found that Salmonella typhimurium strain LT2 (Z) possessed two immunologically distinct, membrane-bound hydrogenase isoenzymes, which were similar in electrophoretic mobilities and apoprotein contents to hydrogenase isoenzymes 1 and 2 of Escherichia coli. The S. typhimurium enzymes cross-reacted with antibodies raised to the respective hydrogenase isoenzy
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11. Effects of cultivation gas phase on hydrogenase of the acetogen Clostridium thermoaceticum.
The effect of cultivation gas phase on the expression and activity of hydrogenase in heterotrophic cultures of Clostridium thermoaceticum was examined. Of the five gas phases tested, hydrogenase was maximal from cells cultivated under CO. Correlations were observed between the level of hydrogenase and the evolution of H2 by growing cultures. Activity stains
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12. Regulation of hydrogenase activity in vegetative cells of Anabaena variabilis.
Heterocyst-free (NH4+-grown) cultures of the cyanobacterium Anabaena variabilis produce a hydrogenase which is reversibly inhibited by light and O2. White or red light at an intensity of 5,000 lx inhibited greater than 95% of the activity. Oxygen at concentrations as low as 0.5% inhibited more than 85% of the hydrogenase in the vegetative cells of CO2-NH4+-g