Interrelationship of Oxygen and Nitrogen Metabolism in the Filamentous Cyanobacterium Oscillatoria chalybea

1989 ◽  
Vol 44 (11-12) ◽  
pp. 946-954 ◽  
Author(s):  
J. Bednarz ◽  
S. Höper ◽  
M. Bockstette ◽  
K. P. Bader ◽  
G. H. Schmid
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Nitrate Reductase ◽  
Nitrogen Source ◽  
Nitrogen Metabolism ◽  
Light Illumination ◽  
Filamentous Cyanobacterium ◽  
Sole Nitrogen Source ◽  
Light Intensities ◽  
Oscillatoria Chalybea

Abstract Filamentous Cyanobacteria. Hydrogen Peroxide, Photosystem II. Nitrogen Metabolism By means of mass spectrometric analysis we have been able to demonstrate H 20 2-production and its decomposition by photosystem II in thylakoids of the filamentous cyanobacterium Oscil­ latoria chalybea. This H2O2-production and its quasi simultaneous decomposition by the S-state system can be readily demonstrated in flash light illumination (K. P. Bader and G. H. Schmid, Biochim. Biophys. Acta 936, 179-186 (1988)) or as shown in the present paper in continuous light at low light intensities. These light conditions correspond essentially to the culturing condition of the organism on nitrate as the sole nitrogen source. Under these conditions, however, electron transport between the two photosystems seems to be mostly disconnected and respiratory activity practically non existent. Under these conditions, on the other hand, nitrate reductase is induced and nitrate reduced. The present paper addresses the question how this organism might solve the metabolic problems of nitrate reduction with such an electron transport system. Tested under high light intensities under which the organism would not grow at all, electron transport between the two photosystems is optimally linked and the system funnels part of its photosynthetically pro­duced electrons into a conventional cyanide-sensitive respiratory electron transport chain and even into an alternative Sham-sensitive (cyanide-insensitive) respiratory chain. This is made possible by the overweight of photosystem II capacity in comparison to photosystem I activity as reported in this paper. Under the conditions described, the cyanobacterium grows also on ar­ginine as the sole nitrogen source. Most interestingly under these conditions nitrate reductase induction is not shut off as is the case with other aminoacids like ornithine or alanine in the medium. Nitrite reductase is not induced in these bacteria, if grown on arginine as the sole nitrogen source. This observation is discussed in context with the fact that arginine is a major storage product (cyanophycin) in this organism and that the observed photosystem II mediated H2O2-production might be correlated with arginine metabolism.

Stimulatory Effects of an Ammonium Salt Biocide on Photosynthetic Electron Transport Reactions

1994 ◽  
Vol 49 (1-2) ◽  
pp. 87-94 ◽  
Author(s):  
Klaus P. Bader ◽  
Susanne Höper
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Ammonium Salt ◽  
Photosystem I ◽  
Reaction Rates ◽  
Filamentous Cyanobacterium ◽  
Relaxation Kinetics ◽  
Photosynthetic Membranes ◽  
Oscillatoria Chalybea ◽  
Kinetics Of

Alkylbenzyldimethylammonium chloride (ABDAC, zephirol) has been shown to improve the functioning of the photosynthetic apparatus of the filamentous cyanobacterium Oscillatoria chalybea (Bader, K. P. (1989) Biochim. Biophys. Acta 975, 399-402). This biocide exerts stimulatory effects on various electron transport reactions in Oscillatoria chalybea and chloroplasts from higher plants. By means of oxygen evolution measurements and of repetitive flash-induced absorption spectroscopy we were able to demonstrate an impact of the drug on the major complexes of photosynthetic membranes, i.e. the water splitting complex, photosystem II and photosystem I. Both, P820- and X320-absorption change signals were enhanced by the addition of ABDAC. Along with the quantitative analysis we investigated the relaxation kinetics of the signals and observed a substantial stabilization of the oxidized states of the respective redox components in the presence of the ammonium salt. Under appropriate conditions the relaxation kinetics of the absorption signals were significantly slowed down. ABDAC also affects photosystem I in Oscillatoria chalybea, but only under conditions, where a donor/acceptor system i.e. an isolated photosystem I reaction with photosystem II being disconnected was measured. Electron transport through the whole chain i.e. with water as the electron donor yielded no effect of the quaternary ammonium salt. It is suggested that this is due to an extremely bad linkage between the two photosystem, each of which, however, shows good reaction rates, when separately measured. The described interactions of the biocide with photosynthetic membranes are not restricted to Oscillatoria chalybea but are also observed with higher plant chloroplasts. In these systems, ABDAC enhances X320- and P700-signals to a comparable extent. In this case the P700-signal is stimulated in assays with electrons which are furnished from water which hints at good coupling between the two photosystems in our tobacco chloroplast preparations.

Induction of Nitrate Reductase Activity by Arginine in the Filamentous Cyanobacterium Oscillatoria chalybea

1991 ◽  
Vol 46 (7-8) ◽  
pp. 591-596 ◽  
Author(s):  
J. Bednarz ◽  
G. H. Schmid
Keyword(s):  
Nitrate Reductase ◽  
Nitrogen Source ◽  
Nitrate Reduction ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Maximal Activity ◽  
Substrate Affinity ◽  
Filamentous Cyanobacterium ◽  
Oscillatoria Chalybea ◽  
Exogenous Nitrogen

Abstract In Oscillatoria chalybea, as in other cyanobacteria, nitrate reduction depends directly on photosynthetic activity. Hence, nitrate reduction occurs only in the light and appears inhibited when photosynthesis is inhibited by the herbicide DCMU . Growth of Oscillatoria cells is possible on a variety of exogenous nitrogen sources in the medium and appears largely independent on the type of nitrogen source. However, if citrulline is the exogenous nitrogen source or if no exogenous nitrogen source is given in the medium, growth appears almost fully inhibited. Nitrate reductase activity measured in French-press particles of nitrate-grown cells is depend­ent on the age of the culture with maximum nitrate reductase activity being reached on the 5th day. Thereafter activity decreases steeply to less than 20% of the maximal activity within 10 days. Besides the growth stage it is the type of exogenous nitrogen source used in the medium which is important for the development of nitrate reductase activity. It appears that in the presence of nitrate, nitrite and arginine, nitrate reductase activity is induced whereas in the presence of ammonia or amino acids like alanine nitrate reductase activity is not induced, as already reported in the literature. Nitrate reductase is also induced if arginine and ammonia are simultaneously offered as exogenous nitrogen source. Arginine metabolism in Oscillatoria cells is characterized by the fact that thylakoid preparations of Oscillatoria catalyze the trans­ formation of arginine to give ornithine and ammonium. The arginine-metabolizing enzyme differs from the usual arginine-induced arginase. The enzyme seems to be constitutive, not manganese-dependent, exhibiting an approximately 5 times higher substrate affinity to arginine than the known arginase. In the present paper we propose that in Oscillatoria it is arginine which induces the synthesis of nitrate reductase.

Phosphatidylglycerol and ß-Carotene Bound onto the D 1-Core Peptide of Photosystem II in the Filamentous Cyanobacterium

1994 ◽  
Vol 49 (1-2) ◽  
pp. 115-124 ◽  
Author(s):  
O. Kruse ◽  
A. Radunz ◽  
G. H. Schmid
Keyword(s):  
Fatty Acid ◽  
Photosystem Ii ◽  
Gel Electrophoresis ◽  
Lipid Analysis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Acid Mixture ◽  
Hexadecenoic Acid ◽  
Filamentous Cyanobacterium ◽  
Intact Cells ◽  
Oscillatoria Chalybea

Photosystem II-particles from the cyanobacterium Oscillatoria chalybea were isolated by fractionating centrifugation. Purification of these particles was achieved by a 22 hours centrifugation over a linear sucrose density gradient at 217.500xg. The obtained particle fraction 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 composed of the core peptides D1 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 electrophoresis assay. Part of the peptides of the 30 kDa-region (D1, D2, MSP) occurred as aggregates 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 phosphatidylglycerol and with the antiserum to β-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 typical fatty acid mixture of this lipid was detected. The lipid is characterized by the fact that the hexadecenoic acid does not exhibit trans-configuration, as is true for phosphatidylglycerol of higher plants and algae, but occurs in cis-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 phosphatidylglycerol increases the hydrophobicity of the peptide and leads to a negatively charged surface 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.

scholarly journals Nitrogen Utilization and Metabolism in Ruminococcus albus 8

2014 ◽  
Vol 80 (10) ◽  
pp. 3095-3102 ◽  
Author(s):  
Jong Nam Kim ◽  
Emily DeCrescenzo Henriksen ◽  
Isaac K. O. Cann ◽  
Roderick I. Mackie
Keyword(s):  
Growth Rate ◽  
Nitrogen Source ◽  
Nitrogen Metabolism ◽  
Enzyme Activities ◽  
Transcript Abundance ◽  
Gene Transcript ◽  
Sole Nitrogen Source ◽  
Ruminococcus Albus ◽  
Content Type ◽  
Maximum Cell

ABSTRACTThe model rumenFirmicutesorganismRuminococcus albus8 was grown using ammonia, urea, or peptides as the sole nitrogen source; growth was not observed with amino acids as the sole nitrogen source. Growth ofR. albus8 on ammonia and urea showed the same growth rate (0.08 h−1) and similar maximum cell densities (for ammonia, the optical density at 600 nm [OD600] was 1.01; and for urea, the OD600was 0.99); however, growth on peptides resulted in a nearly identical growth rate (0.09 h−1) and a lower maximum cell density (OD600= 0.58). To identify differences in gene expression and enzyme activities, the transcript abundances of 10 different genes involved in nitrogen metabolism and specific enzyme activities were analyzed by harvesting mRNA and crude protein from cells at the mid- and late exponential phases of growth on the different N sources. Transcript abundances and enzyme activities varied according to nitrogen source, ammonia concentration, and growth phase. Growth ofR. albus8 on ammonia and urea was similar, with the only observed difference being an increase in urease transcript abundance and enzyme activity in urea-grown cultures. Growth ofR. albus8 on peptides showed a different nitrogen metabolism pattern, with higher gene transcript abundance levels ofgdhA,glnA,gltB,amtB,glnK, andureC, as well as higher activities of glutamate dehydrogenase and urease. These results demonstrate that ammonia, urea, and peptides can all serve as nitrogen sources forR. albusand that nitrogen metabolism genes and enzyme activities ofR. albus8 are regulated by nitrogen source and the level of ammonia in the growth medium.

Mass Spectrometric Analysis of N2-Formation Induced by the Oxidation of Hydrazine and Hydroxylamine in Flash Illuminated Thylakoid Preparations of the Filamentous Cyanobacterium Oscillatoria chalybea

1991 ◽  
Vol 46 (7-8) ◽  
pp. 629-634 ◽  
Author(s):  
P. He ◽  
K. P. Bader ◽  
G . H. Schmid
Keyword(s):  
Mass Spectrometry ◽  
Photosystem Ii ◽  
Oxygen Uptake ◽  
Mass Spectrometric ◽  
Spectrometric Analysis ◽  
Filamentous Cyanobacterium ◽  
High Concentration ◽  
Single Turnover ◽  
Oscillatoria Chalybea ◽  
Light Flashes

In tobacco chloroplasts hydrazine-dependent dinitrogen formation measured by mass spectrometry as the consequence of short saturating light flashes is always linked to a substantial oxygen uptake (G. Renger, K. P. Bader, and G. H. Schmid, Biochim. Biophys. Acta 1015, 288, 1990). However, in thylakoids of the filamentous cyanobacterium Oscillatoria chalybea this dinitrogen formation is not linked to an apparent O2-uptake, even at the high concentration of 1 mм hydrazine. Whereas in tobacco chloroplasts Tris-treatment does not affect hydrazine dependent dinitrogen formation up to a concentration of 3 mм hydrazine, Tris-treatment of thylakoids of 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 presence of hydrazine up to concentrations of 3 mм does not substantially affect photosynthetic O2-evolution. The observed dinitrogen evolution is affected by DCMU regardless whether induced by a single turnover flash or by ten flashes, whereas in tobacco dinitrogen evolution and the O2-uptake linked to it (which is not observed in the cyanobacterium) were clearly not affected by DCMU in the single turnover flash. In Oscillatoria the earlier described Photosystem II-mediated H2O2 formation and decomposition is influenced by hydrazine. In the presence of 300 μм hydrazine the usually present O2-uptake leading to H2O2 formation appears diminished.

Independently Acting Oxygen-Forming Complexes of Photosystem II in Cyanobacteria A Study in the Filamentous Cyanobacterium Oscillatoria chalybea

1997 ◽  
Vol 52 (3-4) ◽  
pp. 169-174 ◽  
Author(s):  
S. Spiegel ◽  
K. Burda ◽  
K. P. Bader ◽  
G. H. Schmid
Keyword(s):  
Photosystem Ii ◽  
Cross Sections ◽  
Dark Adaptation ◽  
Filamentous Cyanobacterium ◽  
Damped Oscillations ◽  
Synechococcus Leopoliensis ◽  
Evolution Pattern ◽  
Oscillatoria Chalybea ◽  
The Individual ◽  
Oxygen Evolving

Abstract It has been postulated that the oxygen-evolving centers of photosystem II do not operate independently in the cyanobacterium Synechococcus leopoliensis in contrast to those of the chlorophyte Chlorella vulgaris and the diatom Phaeodactylum tricornutum (Mauzerall and Dubinsky (1993), Biochim. Biophys. Acta 1183, 123-129). Dependence would mean the existence of charge transfer among adjacent units and would be manifested by different saturation curves for the individual flashes of a sequence (different cross-sections), stronger damped oscillations and oxygen formation under the first flash, independently of the length of dark adaptation. We show in the present publication that in the filamentous cyanobacterium Oscillatoria chalybea the O2-evolution pattern which shows an O2-signal under the first flash (despite dark adaptation) can be explained within the heterogeneous Kok-model, assuming a non-standard initial S-state distribution (Bader, Thibault and Schmid (1983), Z. Naturforsch. 38c. 778-792).

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