| | 1 | Author
| P. He, K. P. Bader, G. H. Schm, G. Renger, K. P. Bader, G. H. Schmid | Requires cookie* | | | Title
| Mass Spectrometric Analysis of N 2-Formation Induced by the Oxidation of Hydrazine and Hydroxylamine in Flash Illuminated Thylakoid Preparations of the Filamentous Cyanobacterium Oscillatoria chalybea  | | | | Abstract
| Analogue In tobacco chloroplasts hydrazine-dependent dinitrogen form ation measured by mass spec trometry as the consequence o f short saturating light flashes is always linked to a substantial oxygen uptake (1990). However, in thylakoids o f the filamentous cyanobacterium Oscillatoria chalybea this dinitrogen formation is not linked to an apparent 0 2-uptake, even at the high concentration o f 1 mM hydrazine. Whereas in tobacco chloroplasts Tris-treatment does not affect hydrazine de pendent dinitrogen formation up to a concentration o f 3 mM hydrazine, Tris-treatment o f thy lakoids o f O. chalybea affects strongly both oxygen evolution and dinitrogen evolution under a single turnover flash as well as under ten flashes. In contrast to tobacco chloroplasts, the pres ence o f hydrazine up to concentrations o f 3 mM does not substantially affect photosynthetic 0-,-evolution. The observed dinitrogen evolution is affected by D C M U regardless whether in duced by a single turnover flash or by ten flashes, whereas in tobacco dinitrogen evolution and the 0-,-uptake linked to it (which is not observed in the cyanobacterium) were clearly not af fected by D C M U in the single turnover flash. In Oscillatoria the earlier described Photosystem II-mediated H-,0-, formation and decom position is influenced by hydrazine. In the presence o f 300 hm hydrazine the usually present 0 2-uptake leading to H:0 : formation appears dimin ished. | | | |
Reference
| Z. Naturforsch. 46c, 629 (1991); received March 21 1991 | | | |
Published
| 1991 | | | |
Keywords
| Filamentous Cyanobacterium, Photosystem II, Water Splitting, S-States, Hydrogen-Peroxide | | | |
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| default:Reihe_C/46/ZNC-1991-46c-0629.pdf | | | | Identifier
| ZNC-1991-46c-0629 | | | | Volume
| 46 | |
| 2 | Author
| K. Burda, P. He, K. P. Bader, G. H. Schmid | Requires cookie* | | | Title
| Temperature Dependence of the 0 2-Oscillation Pattern in the Filamentous Cyanobacterium Oscillatoria chalybea and in Chlorella kessleri | | | | Abstract
| Five characteristic discontinuities of the pattern of oxygen evolution have been detected for the filamentous cyanobacterium Oscillatoria chalybea in the temperature range of 0°C to 30°C. The temperatures at which these discontinuities occur are: ~ 5°C, ~ 11°C, ~ 15°C, ~ 21°C and ~ 25°C. The calculated initial 5-S state distribution, the miss parameter and the fraction of the fast transition S3 —> S0 + 0 2 are affected. The discontinuities are observed at the same transition temperature also for Chlorella kessleri hence are not specific for the cyanobacterium. Based on these studies it is concluded that the not vanishing oxygen signal under the first flash of a flash train in Oscillatoria cannot have its origin in interactions between oxygen-evolving complexes. A decrease of temperature should slow down the ex pected charge exchanges, improve the oscillations, thus reduce or lower the first two oxygen amplitudes of the oscillatoria pattern. Lowering of the temperautres improves the oscillations but does not lower the first 0 2 signal of the pattern. | | | |
Reference
| Z. Naturforsch. 51c, 823 (1996); received June 14/ | | | |
Published
| 1996 | | | |
Keywords
| 0 2-Oscillation Pattern, Charge Exchange, Temperature D ependence, Filamentous Cyanobacterium | | | |
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| default:Reihe_C/51/ZNC-1996-51c-0823.pdf | | | | Identifier
| ZNC-1996-51c-0823 | | | | Volume
| 51 | |
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