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1Author    Georg SchmettererRequires cookie*
 Title    Formation of Hydrocarbons by Photobleaching Cyanobacterium, A nacystis nidulans  
 Abstract    The cyanobacterium Anacystis nidulans is bleached when subjected to both light and 0 2 to­ gether with suitable (pre)treatment o f the cells such as incubation at high (^ 4 8 °C) or low (S 17 °C) temperatures, or in presence o f metabolic inhibitors, or o f substances forming com­ plexes with divalent cations. Concomitantly degradation o f the intracellular membranes is ob­ served (G. Schmetterer, G. A. Peschek, Biochem. Physiol. Pflanzen 176, 9 0 —100 (1981)). The same three conditions cause formation o f hydrocarbons, mostly ethane, a characteristic product of lipid peroxidation. Ethane production is unchanged and still light-sensitive even when no more pigments can be detected in the cells. In "white" cells light-dependent 0 2-uptake is also observed. The action spectrum of this process suggests that "completely" bleached cells retain very small amounts of residual chlorophyll, which must be unusually resistant to photooxidation. 
  Reference    Z. Naturforsch. 37c, 205 (1982); received November 51981 
  Published    1982 
  Keywords    Photooxidation, Ethane Production, Cyanobacterium, Anacystis nidulans, Lipid Peroxidation 
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 TEI-XML for    default:Reihe_C/37/ZNC-1982-37c-0205.pdf 
 Identifier    ZNC-1982-37c-0205 
 Volume    37 
2Author    KlausP. Bader, Anja RöbenRequires cookie*
 Title    Mass Spectrometric Detection and Analysis of Nitrogen Fixation in Oscillatoria chalybea  
 Abstract    By means of mass spectroscopic m easurements in an artifical gas atmosphere containing the stable nitrogen isotope 15N2 we were able to demonstrate nitrogen fixation capacity in the filamentous cyanobacterium Oscillatoria chalybea. Our technique proved to be well-suited also for investigations on the light-induced nitrogen fixation in the purple bacteria Rhodobacter sphaeroides and Rhodobacter capsulatus. Oscillatoria chalybea grown without combined nitrogen showed a substantial 15N2-uptake which could clearly be correlated with nitrogen fixation. Nitrate grown cultures did not show this nitrogen uptake or only to a minimal extent. Addition of ammonium chloride resulted in a rapid deactivation of the nitro-genase system. Similar observations have been made with other so-called switch-off effectors like phenazine methosulfate. The structural integrity of the filaments appeared to be a pre­ requisite for nitrogen fixation also in this organism, as even mild mechanical homogenization strongly inhibited the N2-uptake signals. Illumination of the assays under conditions where the photooxidition of water is not operational (Bader, K. P. (1994), Biochim. Biophys. A cta 1188, 2 1 3 -2 1 9) did not affect the nitrogen fixation in Oscillatoria chalybea. Illumination of cultures with concom itant release of oxygen from the w ater splitting reaction resulted in strong inhibition of 15N2-uptake. 
  Reference    Z. Naturforsch. 50c, 199 (1995); received November 11 1994/January 30 1995 
  Published    1995 
  Keywords    Mass Spectrometry, Nitrogen Fixation, Photosynthesis, Cyanobacterium 
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 TEI-XML for    default:Reihe_C/50/ZNC-1995-50c-0199.pdf 
 Identifier    ZNC-1995-50c-0199 
 Volume    50 
3Author    Refat Abdel-Basset, KlausP. BaderRequires cookie*
 Title    Characterization of Hydrogen Photoevolution in Oscillatoria chalybea Detected by Means of Mass Spectrometry  
 Abstract    The filamentous non-heterocystous cyanobacterium Oscillatoria chalybea is capable to photoevolve molecular hydrogen when the cells are flushed to anaerobiosis with nitrogen or argon and exposed to short light flashes or continuous light. The light-induced hydrogen gas exchange of Oscillatoria chalybea has been investigated by direct determ ination of dynamic changes in the hydrogen partial pressure at m/e=2 in the H/D collector of a mass spectromet-ric set-up. By means of this technique also the time curves of the light-induced hydrogen gas exchange could be directly recorded. Depending on the chlorophyll concentration in the measuring cell we observed an increasing hydrogen content of the aqueous Oscillatoria sus­ pension i.e. a dark evolution of molecular hydrogen. Upon the onset of light an initial rise of the H 2-signal was observed which was increasingly mixed or followed by a hydrogen uptake. The capability to photoevolve molecular hydrogen was maximal with young cultures and decreased with increasing age. The hydrogen evolution signals require relatively short dark adaptation to get pronounced; few seconds suffice for 2/3 of the hydrogen evolution amplitude. Prolonged dark adaptation maximizes the flash amplitudes. The hydrogen evolu­ tion signals do not deactivate by low flash frequency Oscillatoria chalybea evolves molecular hydrogen following growth on nitrogen free or nitrate containing medium. Increase of the oxygen partial pressure of the assays completely abolishes the hydrogen evolution signals with an I50-value of 6 ^im. 
  Reference    Z. Naturforsch. 52c, 775—781 (1997); received September 8/October 17 1997 
  Published    1997 
  Keywords    Photosynthesis, Mass Spectrometry, Hydrogen Photoevolution, Cyanobacterium 
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 TEI-XML for    default:Reihe_C/52/ZNC-1997-52c-0775.pdf 
 Identifier    ZNC-1997-52c-0775 
 Volume    52 
4Author    NavassardV. Karapetyanab, Ute Windhövel3 ', AlfredR. Holzwarthc, Peter BögeraRequires cookie*
 Title    Physiological Significance of Overproduced Carotenoids in Transformants of the Cyanobacterium Synechococcus PCC7942  
 Abstract    The functional location of carotenoids in the photosynthetic apparatus of -crtB and -pys transformants of the cyanobacterium Synechococcus PCC7942 was studied and compared with a control strain -pF P l-3. These transformants overproduce carotenoids due to the insertion of an additional foreign phytoene synthase gene. A higher carotenoid content was found for -crtB and -pys transformants both in whole cells and isolated membranes; the -crtB transformant was also enriched with chlorophyll. 77-K fluorescence emission and excita­ tion spectra of the phycobilin-free membranes were examined for a possible location of overproduced carotenoids in pigment-protein complexes in situ. A similar ratio of the ampli­ tudes of fluorescence bands at 716 and 695 nm emitted by photosystems I and II, found for the three strains, indicates that the stoichiometry between photosystems of the transformants was not changed. Overproduced carotenoids are not located in the core antenna of photosys­ tem I, since 77-K fluorescence excitation spectra for photosystem I of isolated membranes from the studied strains do not differ in the region of carotenoid absorption. When illumi­ nated with light of the same intensity but different quality, absorbed preferentially by either carotenoids, chlorophylls or phycobilins, respectively, oxygen evolution was found always higher in the transformants -crtB and -pys than in -p F P l-3 control cells. Identical kinetics of fluorescence induction of all strains under carotenoid excitation did not reveal a higher activity of photosystem II in cells enriched with carotenoids. It is suggested that overpro­ duced carotenoids of the transformants are not involved in photosynthetic light-harvesting; rather they may serve to protect the cells and its membranes against photodestruction. 
  Reference    Z. Naturforsch. 54c, 191—198 (1999); received December 18 1998 
  Published    1999 
  Keywords    Carotenoid, Chlorophyll, Cyanobacterium, Fluorescence, Oxygen Evolution 
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 TEI-XML for    default:Reihe_C/54/ZNC-1999-54c-0191.pdf 
 Identifier    ZNC-1999-54c-0191 
 Volume    54 
5Author    Wolfgang Lockau, Susanne PfefferRequires cookie*
 Title    A Cyanobacterial ATPase Distinct from the Coupling Factor of Photophosphorylation  
 Abstract    A particle-bound, M g2+-dependent A TPase activity is investigated in cell-free extracts o f the cyanobacterium Anabaena variabilis. The enzym e can be clearly distinguished from the 
  Reference    Z. Naturforsch. 37c, 658 (1982); received March 231982 
  Published    1982 
  Keywords    Cyanobacterium, Anabaena variabilis, ATPase, Coupling Factor, Cytochrom e Oxidase 
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 TEI-XML for    default:Reihe_C/37/ZNC-1982-37c-0658.pdf 
 Identifier    ZNC-1982-37c-0658 
 Volume    37 
6Author    Divya Mishra, Ahlert SchmidtRequires cookie*
 Title    Regulation and Partly Purification of the ATP-Sulfurylase from the Cyanobacterium Synechococcus 6301  
 Abstract    ATP-sulfurylase from the cyanobacterium Synechococcus 6301 was regulated in vivo during growth in batch culture. The activity was highest at the third day after inoculation, declining afterwards to a level found in resting cells. During growth with air supplemented with 2% CO, this activity increased 3-fold compared to controls grown with normal air as C 0 2 source. Addition o f either nitrite or urea enhanced ATP-sulfurylase activity about 2-fold, whereas cys­ teine and especially methionine decreased ATP-sulfurylase activity to 5% o f controls without treatment. The ATP-sulfurylase was purified by conventional techniques using D EAE-cellulose chro­ matography and further separation on blue sepharose achieving a 250-fold increase in the spe­ cific activity. An apparent o f 5 for APS and o f 40 |iM for pyrophosphate was deter­ mined with the purified enzyme fraction. 
  Reference    Z. Naturforsch. 47c, 95 (1992); received September 26 1991 
  Published    1992 
  Keywords    ATP-Sulfurylase, Cyanobacterium, Synechococcus, Sulfate A ctivation, Regulation 
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 TEI-XML for    default:Reihe_C/47/ZNC-1992-47c-0095.pdf 
 Identifier    ZNC-1992-47c-0095 
 Volume    47 
7Author    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 
8Author    O. Kruse, G. H. SchmidRequires cookie*
 Title    The Role of Phosphatidylglycerol as a Functional Effector and Membrane Anchor of the D l-C ore Peptide from Photosystem II-Particles of the Cyanobacterium Oscillatoria chalybea  
 Abstract    The intrinsic polypeptide D l, isolated from photosystem (PS) Il-particles of the cyanobac­ terium Oscillatoria chalybea, was obtained by electroelution and fractionated extraction with organic solvents. Purification was demonstrated by Western blotting and amino acid sequenc­ ing. By carrying out D1 -immunization in rabbits a polyclonal monospecific D1-antiserum was obtained. For the qualitative characterization of D1 as a lipid-binding peptide, the effect of the lipids phosphatidylglycerol (PG), monogalactosyldiacylglyceride (M G D G) and phosphatidylcho­ line (PC) on PSII-oxygen evolution was analysed in reconstitution experiments. In these experiments purified photosystem II (PSII)-particle preparations were treated with the en­ zyme phospholipase A 2 and supplemented with lipid emulsions. We were able to show that the inhibition of electron transport, as the consequence of this lipase treatment, was only relieved, if phosphatidylglycerol was added to the preparation. A model was proposed, in which phosphatidylglycerol is a functional effector for the optimal conformation of D 1 in the PSII core complex. Phosphatidylglycerol molecules are unusually tightly bound to the D1 peptide by hydrophobic interactions. A covalent binding seems not probable. The localisation of phosphatidylglycerol binding sites was found by trypsin treatment of D1 and analysis of the obtained oligopeptides with HPLC and immunoblotting. The binding sites could be con­ fined to the hydrophobic amino acid section between arginine 27 and arginine 225. which is known to be the membrane anchor of D l. This has led us to the conclusion that the phospho­ lipid phosphatidylglycerol plays an important role for anchoring the Dl-peptide and for its orientation in the thylakoid membrane. Phosphatidylglycerol with its high amount of palmitic acid has in prokaryotic cyanobacteria apparently a role in stabilization and orientation. The high turn-over of D l and the spatial separation of the synthesis-and incorporation-site in the membrane, developed during evolution in eukaryotic organisms, might have changed the requirement on the mobility and the orientation of D l in photosynthetic membranes. 
  Reference    Z. Naturforsch. 50c, 380—390 (1995); received December 12 1994/February 24 1995 
  Published    1995 
  Keywords    Dl-Peptide, Phosphatidylglycerol, Lipid-Protein Binding, Cyanobacterium, PSII-Complex 
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 TEI-XML for    default:Reihe_C/50/ZNC-1995-50c-0380.pdf 
 Identifier    ZNC-1995-50c-0380 
 Volume    50 
9Author    UweJ. Jürgens, Roland BenzRequires cookie*
 Title    Pore-Forming Activity of Outer Membrane Extracts from the Unicellular Cyanobacterium Synechocystis sp. PCC 6714  
 Abstract    Cell walls of the unicellular cyanobacterium Synechocystis sp. PCC 6714, isolated from cell homogenates, were found to be unusually resistant against extraction with various detergents, organic solvents, chaotropic agents, and proteases. The major outer membrane proteins (M r 67,000; 61,000; 94,000) were solubilized by differential SDS-extraction and purified by prepara­ tive SDS-PAGE. The extracted proteins, reconstituted into lipid bilayer membranes, formed two types of pores with single-channel conductances of 2.2 nS (pore diameter of 1.4 nm) and 0.3 nS (pore diameter not determined), respectively. Carotenoids and lipopolysaccharide were found to be associated with the extracted major proteins. 
  Reference    Z. Naturforsch. 44c, 165—169 (1989); received October 10 1988 
  Published    1989 
  Keywords    Carotenoid-Binding Protein, Cyanobacterium, Outer Membrane Protein, Porin, Protease-Resist­ ance, Synechocystis 
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 TEI-XML for    default:Reihe_C/44/ZNC-1989-44c-0165.pdf 
 Identifier    ZNC-1989-44c-0165 
 Volume    44 
10Author    B. M. Aršálek, M. Šimek, R. J. SmithRequires cookie*
 Title    The Effect of Ecdysterone on the Cyanobacterium Nostoc 6720  
 Abstract    The insect hormone ecdysterone stimulated dinitrogen fixation, heterocyst formation, cell size and protein synthesis in suspension cultures of the cyanobacterium Nostoc 6720 within 48 h when added to the culture at concentrations between 10-9 and 10-7 M . In the presence of the hormone the volume of vegetative cells increased by 6-fold and that of heterocysts by near­ ly twice as compared to untreated controls. All the observed effects were inhibited by the cal-cium-calmodulin inhibitor, trifluoperazine. Cholesterol used as a null control had no signifi­ cant effect. 
  Reference    Z. Naturforsch. 47c, 726—730 (1992); received May 26/July 27 1992 
  Published    1992 
  Keywords    Cyanobacterium, Nostoc PCC 6720, Ecdysterone, Enhanced Nitrogen Fixation, Cell Size, Protein Synthesis 
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 TEI-XML for    default:Reihe_C/47/ZNC-1992-47c-0726.pdf 
 Identifier    ZNC-1992-47c-0726 
 Volume    47 
11Author    O. Kruse, A. Radunz, G. H. SchmidRequires cookie*
 Title    Phosphatidylglycerol and ß-Carotene Bound onto the D 1-Core Peptide of Photosystem II in the Filamentous Cyanobacterium Oscillatoria chalybea  
 Abstract    -particles from the cyanobacterium Oscillatoria chalybea were isolated by fractionating centrifugation. Purification of these particles was achieved by a 22 hours cen­ trifugation over a linear sucrose density gradient at 217.500 X g. The obtained particle frac­ tion exhibited an oxygen evolution activity which corresponded to three times the rate of intact cells and to five times the rate of intact thylakoids. The chlorophyll protein ratio was 1:10 and the ratio manganese/chlorophyll 1:34. SDS-polyacrylamide gel electrophoresis showed that the photosystem Il-fraction is com­ posed of the core peptides D 1 and D2, the chlorophyll-binding peptides CP 43 and CP 47, the extrinsic 33 kDa peptide (manganese stabilizing peptide, MSP) and phycobiliproteins with molecular masses between 16 to 20 kDa. Cyt b559 was not detected in our gel electro­ phoresis assay. Part of the peptides of the 30 kDa-region (D 1, D 2, MSP) occurred as aggre­ gates with a molecular mass of 60 to 66 kDa. The D 1-peptide was isolated from the PS Il-preparation by SDS-gel electrophoresis. The intrinisic peptide reacts in the Western blot procedure with the antiserum to phosphatidyl­ glycerol and with the antiserum to ß-carotene. Incubation of the peptide with the antisera to monogalactosyldiglyceride, sulfoquinovosyldiglyceride and zeaxanthine resulted negatively. The binding of phosphatidylglycerol onto the D 1-peptide was confirmed by lipid analysis in HPLC and fatty acid analysis by gas chromatography. Only this lipid, respectively the typi­ cal fatty acid mixture of this lipid was detected. The lipid is characterized by the fact that the hexadecenoic acid does not exhibit rraws-configuration, as is true for phosphatidylglycerol of higher plants and algae, but occurs in cw-configuration. With the antibody being directed towards the glycerol-phosphate residue and not towards the fatty acids, it can be concluded from the reaction of the antibodies with the bound lipid that the lipid is bound to the peptide via the fatty acid. The negatively charged phosphatidyl­ glycerol increases the hydrophobicity of the peptide and leads to a negatively charged sur­ face favouring binding of cations like calcium and magnesium. The fact that incubation of this PS Il-fraction with phospholipase inhibits photosynthetic activity by 25% which can be fully restored by addition of phosphatidylglycerol, shows that bound phosphatidylglycerol has a functional role. 
  Reference    Z. Naturforsch. 49c, 115—124 (1994); received July 16/October 181993 
  Published    1994 
  Keywords    D 1-Peptide, Phosphatidylglycerol, ß-Carotene, Antibody, Lipid-Protein Binding, Cyanobacterium, Manganese Stabilizing Peptide Photosystem II 
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 TEI-XML for    default:Reihe_C/49/ZNC-1994-49c-0115.pdf 
 Identifier    ZNC-1994-49c-0115 
 Volume    49 
12Author    Gottfried Martin, Peter BögerRequires cookie*
 Title    Two Ways of Hydrogen Peroxide Formation in the Oxidative Inactivation of Cyanobacterial Glutamine Synthetase  
 Abstract    Using crude extracts from the cyanobacterium Anabaena variabilis glutamine synthetase (GS) activity was rapidly irreversibly reduced to about 60% during dark incubation ("sponta­ neous GS inactivation"). An additional decrease was observed by the addition of ammonia in the light ("ammonia-m ediated inactivation"). Both effects were prevented by EDTA, MnCl2 or catalase indicative of the involvement of H 20 2. This is a key interm ediate in oxida­ tive enzyme inactivation. In both spontaneous and am monia-mediated GS inactivation H 20 2 is produced in different ways. Spontaneous inactivation is prevented by depletion of reduced pyridine nucleotides which apparently donate electrons to produce H 20 2. Fractionation of the crude extract showed that the light-enhanced GS inactivation by ammonia required the presence of thylakoid membranes. The photosynthesis inhibitor DCM U decreased GS inacti­ vation by ammonia. For the inactivation in the light apparently H 20 2 is produced from super­ oxide during photosynthetic electron transport. 
  Reference    Z. Naturforsch. 52c, 812—816 (1997); received August 12 1997 
  Published    1997 
  Keywords    Glutamine Synthetase, Protein Oxidation Ammonia Effect, Photosynthetic Hydrogen Peroxide Production, Cyanobacterium, Anabaena variabilis 
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 TEI-XML for    default:Reihe_C/52/ZNC-1997-52c-0812.pdf 
 Identifier    ZNC-1997-52c-0812 
 Volume    52