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1981 (1)
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1Author    PatrickC. Hallenbeck, LeonV. Kochian, JohnR. BenemannRequires cookie*
 Title    Hydrogen Evolution Catalyzed by Hydrogenase in Cultures of Cyanobacteria  
 Abstract    Cultures of Anabaena cylindrica, grown on media containing 5 m M N H 4C1 (which represses heterocyst formation), evolved hydrogen after a period o f dark incubation under an argon atmosphere. This hydrogen production was not due to nitrogenase activity, which was nearly undetectable, but was due to a hydrogenase. Cultures grown on media with tungsten substituted for molybdenum had a high frequency of heterocysts (15%) and inactive nitrogenase after nitrogen starvation. The hydrogenase activity of these cultures was three-fold greater than the activity of non-heterocystous cultures. The effects o f oxygen inhibition on hydrogen evolution by hetero-cystous cultures suggest that two pools o f hydrogenase activity exist — an oxygen sensitive hydrogen evolution in vegetative cells and a relatively oxygen-resistent hydrogen evolution in heterocysts. In either case, inhibition by oxygen was reversible. Light had an inhibitory effect on net hydrogen evolution. Hydrogen production in vitro was much higher than in vivo, indicating that in vivo hydrogenase activity is limited by endogenous reductant supply. 
  Reference    Z. Naturforsch. 36c, 87 (1981); received June 13/August 25 1980 
  Published    1981 
  Keywords    Hydrogenase, Cyanobacteria, Heterocysts, Hydrogen Evolution, Hydrogen Metabolism 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0087.pdf 
 Identifier    ZNC-1981-36c-0087 
 Volume    36 
2Author    Ulrike Strohmeier, ChristianG. Erdes3, Wolfgang LockaubRequires cookie*
 Title    Proteolysis in Heterocyst-Forming Cyanobacteria: Characterization of a Further Enzyme with Trypsin-Like Specificity, and of a Prolyl Endopeptidase from Anabaena variabilis  
 Abstract    of the cyanobacterium Anabaena variabilis ATCC 29413 and an en­ gineered mutant that lacks an intracellular protease cleaving after Lys and Arg (Maldener, Lockau, Cai, and Wolk, Mol. Gen. Genet. 225, 113-120 (1991)) were separated by ion ex­ change chromatography, and protease profiles determined using azocasein, Na-benzoyl-D,L-arginine-4-nitroanilide and N-carbobenzoxy-glycyl-L-proline-4-nitroanilide as substrates. A second enzyme cleaving at the carboxyl side of lysine and arginine, and a prolyl endopepti­ dase were detected, enriched and characterized. Both proteolytic enzymes appear to be located in the periplasm. 
  Reference    Z. Naturforsch. 49c, 70—78 (1994); received September 29/December 81993 
  Published    1994 
  Keywords    Anabaena variabilis, Cyanobacterium, Heterocysts, Proteolytic Enzymes, Prolyl Endopeptidase Soluble extracts 
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 TEI-XML for    default:Reihe_C/49/ZNC-1994-49c-0070.pdf 
 Identifier    ZNC-1994-49c-0070 
 Volume    49 
3Author    Anneliese Ernst, Wolfgang Kerfin, Hartmut Spiller, Peter BögerRequires cookie*
 Title    External Factors Influencing Light-Induced Hydrogen Evolution by the Blue-Green Alga, Nostoc muscorum  
 Abstract    This study was conducted to determine some physiological conditions which influence light-in­ duced hydrogen evolution by intact cells of the blue-green alga Nostoc muscorum. This activity was found to be dependent on the age of the culture, cultivation temperature, ageing of the cells, and on gassing the cultures with nitrogen or air. Nitrogenase is particularly ac­ tive after cultivation at 22 °C but not at 32 °C although growth is about the same. The molar ratio of acetylene reduction to hydrogen evolution -both gas exchanges obviously catalyzed by nitrogen­ ase -is also dependent on age and temperature of the culture. A hydrogen-consuming ("up­ take") hydrogenase activity is present and affected by prolonged microaerobic, but not by aerobic growth conditions, and stimulated by light. External factors during growth apparently influence differently the activities of nitrogenase and uptake hydrogenase. Consequently -besides the electron donor supply -net light-induced hydro­ gen evolution by intact cells is dependent on these two variable activities. 
  Reference    Z. Naturforsch. 34c, 820 (1979); received May 8/June 11 1979 
  Published    1979 
  Keywords    Photoproduction of Hydrogen, Cyanobacteria, Heterocysts, Water Photolysis, Nitrogenase, Uptake Hydrogenase 
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 TEI-XML for    default:Reihe_C/34/ZNC-1979-34c-0820.pdf 
 Identifier    ZNC-1979-34c-0820 
 Volume    34