Photosynthetic and respiratory oxygen gas exchange measured by mass spectrometry in the filamentous cyanobacterium Oscillatoria chalybea in dependence on the nitrogen source in the growth medium

1989 ◽  
Vol 974 (3) ◽  
pp. 303-310 ◽  
Author(s):  
K.P. Bader ◽  
G.H. Schmid
Keyword(s):  
Mass Spectrometry ◽  
Gas Exchange ◽  
Nitrogen Source ◽  
Growth Medium ◽  
Filamentous Cyanobacterium ◽  
Oscillatoria Chalybea ◽  
Oxygen Gas

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.

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.

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.

scholarly journals Evidence for Naturally Produced Beauvericins Containing N-Methyl-Tyrosine in Hypocreales Fungi

Toxins ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 182 ◽  
Author(s):  
Monika Urbaniak ◽  
Łukasz Stępień ◽  
Silvio Uhlig
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Liquid Chromatography ◽  
Oxygen Atom ◽  
Growth Medium ◽  
Structural Isomer ◽  
Liquid Chromatography Mass Spectrometry ◽  
Natural Production ◽  
Additional Oxygen Atom ◽  
Insight Into

Beauvericin is a depsipeptide mycotoxin. The production of several beauvericin analogues has previously been shown among various genera among Hypocreales fungi. This includes so-called beauvenniatins, in which one or more N-methyl-phenylalanine residues is exchanged with other amino acids. In addition, a range of “unnatural” beauvericins has been prepared by a precursor addition to growth medium. Our aim was to get insight into the natural production of beauvericin analogues among different Hypocreales fungi, such as Fusarium and Isaria spp. In addition to beauvericin, we tentatively identified six earlier described analogues in the extracts; these were beauvericin A and/or its structural isomer beauvericin F, beauvericin C, beauvericin J, beauvericin D, and beauvenniatin A. Other analogues contained at least one additional oxygen atom. We show that the additional oxygen atom(s) were due to the presence of one to three N-methyl-tyrosine moieties in the depsipeptide molecules by using different liquid chromatography–mass spectrometry-based approaches. In addition, we also tentatively identified a beauvenniatin that contained N-methyl-leucine, which we named beauvenniatin L. This compound has not been reported before. Our data show that N-methyl-tyrosine containing beauvericins may be among the major naturally produced analogues in certain fungal strains.

A Study on the Life Time of the S3-State in the Filamentous Cyanobacterium Oscillatoria chalybea

1994 ◽  
Vol 49 (1-2) ◽  
pp. 108-114 ◽  
Author(s):  
G. H. Schmid ◽  
K. P. Bader ◽  
R. Schulder
Keyword(s):  
Steady State ◽  
Molecular Oxygen ◽  
Life Time ◽  
State System ◽  
Filamentous Cyanobacterium ◽  
Entire System ◽  
Higher Plant ◽  
Oscillatoria Chalybea ◽  
S States ◽  
Reduced State

In the filamentous cyanobacterium Oscillatoria chalybea deactivation of the S-states starting from steady-state conditions in which S0 = S1 = S2 = S3 = 25% reveals that S3 deactivates to a finite level of approx. 10%. This level is reached under normal conditions between 10-15 seconds. This quasi metastable S3 meets all requirements for S3 in that one flash eliminates this redox conditions to give S4 and therewith molecular oxygen. An analysis of the cyanobacterial S-state system in the 5-state Kok model shows that the S-state population in the dark adapted sample contains no contribution from S-1 or a more reduced condition which under normal conditions is the case for Chlorella or higher plant chloroplasts. Hence under standard conditions, the Oscillatoria condition is a pure Kok-4-condition in which S0 is the most reduced state. Under these conditions S2 seems to deactivate to S1 and S3 to S2 and to a smaller extent to S0. In the presence of the ADRY-reagent Ant-2-p (2-(3-chloro-4-trifluoromethyl)- anilino-3,5-dinitrothiophene) introduced by Renger (Biochim. Biophys. Acta 256,428,1972), which is supposed to specifically act on the S3-state (and thereby on S2), not only the deactivation kinetic of S3 (and S2) is accelerated (hence the life time of the S3-state is shortened), but also the level of metastable S3 becomes practically zero. An analysis of the deactivation pattern shows that the agent changes the mode of deactivation of the entire system. Thus, it is seen that after deactivation of a sample in presence of this agent the dark population of S-states contains the more reduced redox condition S-1 It looks as if in this condition S2 deactivates not only to S1 but also to an appreciable extent by two steps to S-1 Another agent ABDAC (alkyl-benzyl-dimethyl-ammoniumchloride) seems to lengthen the lifetime of the S2 and S3 condition in this cyanobacterium by apparently acting on the membrane condition.

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.

Quantification of carbohydrate oxidation by respiratory gas exchange and isotopic tracers

1995 ◽  
Vol 268 (4) ◽  
pp. E789-E796 ◽  
Author(s):  
T. S. Glamour ◽  
A. J. McCullough ◽  
P. J. Sauer ◽  
S. C. Kalhan
Keyword(s):  
Mass Spectrometry ◽  
Gas Exchange ◽  
Plasma Glucose ◽  
Glucose Oxidation ◽  
Respiratory Exchange Ratio ◽  
Healthy Adult ◽  
Narrow Range ◽  
Tracer Method ◽  
Isotopic Tracers ◽  
Metabolic States

Estimates of glucose oxidation measured by indirect respiratory calorimetry and by [U-13C]glucose tracer were compared as a function of respiratory exchange ratio (RER) in 14 studies performed on 9 healthy adult subjects. RER was varied between 0.7 and 1.04, either by fasting or by infusing glucose. 13C enrichment of plasma glucose and expired CO2 were measured by mass spectrometry. The two methods gave similar results when the nonprotein respiratory quotient (NPRQ) was between 0.76 and 0.90. Glucose oxidation by the tracer method was quantified to be higher than that by respiratory calorimetry when NPRQ was < 0.76; it was lower than the respiratory calorimetry estimate when NPRQ was > 0.90. The discrepancy between the two methods at low RER may represent the contribution of gluconeogenesis, whereas, at high RER, the discrepancy may be the consequence of lipogenesis. We conclude that respiratory calorimetry and [13C]glucose tracer give comparable results only in a narrow range of RER. These data are important when the disposal of glucose is compared using these techniques in different metabolic states with varying respiratory quotients.

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