Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Growth yields and the efficiency of oxidative phosphorylation of Paracoccus denitrificans during two- (carbon) substrate-limited growth (1979)
    Springer
    Archives of microbiology 121 (1979), S. 213-223 
    Details
    ISSN: 1432-072X
    Keywords: Oxidative phosphorylation ; Chemostat culture ; Growth yield ; Mixed substrates ; Ribulose-bisphosphate cycle ; Cytochrome c ; Single cell protein ; Methanol ; Paracoccus denitrificans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Paracoccus denitrificans was grown aerobically during two-(carbon)substrate-limitation on mannitol and methanol in chemostat cultures. Theoretical growth parameters were calculated based on the presence of 2 or 3 sites in the electron-transport chain of Paracoccus denitrificans. Experimental growth parameters determined during two-(carbon)substrate growth were conform to the presence of 3 sites of oxidative phosphorylation, while cells grown only on mannitol possessed 2 sites. The maximum growth yield on adenosine triphosphate (ATP), corrected for maintenance requirements, determined in chemostat experiments in which the methanol concentration is less than 2.11 times the mannitol concentration was 8.6 g of biomass. When the methanol concentration was more than 2.11 times the mannitol concentration the maximum growth yield on adenosine triphosphate decreased due to the more energy consuming process of CO2-assimilation. Cells use methanol only as energy source to increase the amount of mannitol used for assimilation purposes. When the methanol concentration in chemostat experiments was more than 2.11 times the mannitol concentration, all mannitol was used for assimilation and excess energy derived from methanol was used for CO2-assimilation via the ribulose-bisphosphate cycle. The synthesis of ribulosebisphosphate carboxylase was repressed when the methanol concentration in chemostat experiments was less than 2.11 times the mannitol concentration or when Paracoccus denitrificans was grown in batch culture on both methanol and mannitol. When in chemostat experiments the methanol concentration was more than 2.11 times the mannitol concentration ribulose-bisphosphate carboxylase activity could be demonstrated and CO2-assimilation will occur. It is proposed that energy produced in excess activates or derepresses the synthesis of the necessary enzymes of the ribulose-bisphosphate cycle in Paracoccus denitrificans. Consequently growth on any substrate will be carbonas well as energy-limited. When methanol is present in the nutrient cells of Paracoccus denitrificans synthesize a CO-binding type of cytochrome c, which is essential for methanol oxidase activity. The reason for the increase in efficiency of oxidative phosphorylation from 2 to 3 sites is most probably the occurrence of this CO-binding type of cytochrome c in which presence electrons preferentially pass through the a-type cytochrome region of the electron-transport chain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425058
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Energy conservation during nitrate respiration in Paracoccus denitrificans (1977)
    Springer
    Archives of microbiology 112 (1977), S. 17-23 
    Details
    ISSN: 1432-072X
    Keywords: Oxidative phosphorylation ; Proton translocation ; Continuous culture ; Maintenance energy ; Growth yield ; Nitrate respiration ; Paracoccus denitrificans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract P/2e ratios were calculated from anaerobic chemostat cultures of Paracoccus denitrificans with nitrogenous oxides as electron acceptor. P/2e ratios were calculated, using the Y ATP max values determined for aerobic cultures. When succinate was the carbon and energy source the average P/2e values of the sulphate-and succinate-limited cultures with nitrate as electron acceptor were 0.5 and 0.7, respectively, and of the nitrite-limited culture 0.9. With gluconate as carbon and energy source the average P/2e values of the gluconate-limited with nitrate as electron acceptor and nitrate limited cultures were 0.9 and 1.1, respectively. →H+/O ratios measured in cells obtained from sulphate-, succinate, nitrite-, gluconate-and nitratelimited cultures yielded respective average values of 3.4, 4.5, 3.5, 4.8 and 6.2 for endogenous substrates. From our data we conclude that sulphate-and nitritelimitation causes the loss of site I phosphorylation. Nitrite has no influence on the maximum growth yield on ATP. We propose that metabolism in heterotrophically grown cells of Paracoccus dentrificans is regulated on the level of phosphorylation in the site I region of the electron transport chain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446649
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Electron-transport chain and coupled oxidative phosphorylation in methanol-grown Paracoccus denitrificans (1978)
    Springer
    Archives of microbiology 118 (1978), S. 13-20 
    Details
    ISSN: 1432-072X
    Keywords: Methanol dehydrogenase ; Autotrophic growth ; Electron transport chain ; Oxidative phosphorylation ; Proton translocation ; Paracoccus denitrificans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Methanol dehydrogenase of Paracoccus denitrificans was shown to be very similar to the enzyme of Pseudomonas sp, M. 27. The K m value for methanol with excess activator (ammonium ions) is 35 μM. The pH optimum for enzyme activity with 2,6-dichlorophe-nolindophenol as electronacceptor was at 9.0 A CO-binding type of cytochrome c was present only in cells grown with methanol as carbon and energy source. It has been shown that methanol-oxidation involves electron-transport via cytochrome c and an a-type cytochrome to oxygen. Antimycin A did not inhibit this electron transport and 90% inhibition was obtained by 375 μM potassium cyanide. Electron transport from endogenous substrates is possible via cytochrome b and possibly cytochrome o to oxygen. Potassium cyanide inhibited 90% of the electron transport via this pathway at a concentration of 1.42 mM. Measurement of respiration-driven proton translocation proved that during oxidation of methanol to formaldehyde by oxygen one mole of adenosine triphosphate is synthesized in the site 3 region of the electron transport chain. The → H+/O value found confirmed the → H+/site ratio of 3–4 found in heterotrophic grown cells. During electron transport from endogenous substrates to oxygen there is a possible synthesis of 3 moles of adenosine triphosphate. In heterotrophically grown cells electron transfer to oxygen follows almost only the branch of the respiratory chain containing cytochrome o. In methanol-grown cells the pathway via the a-type cytochrome seems more important.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00406068
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Energetic aspects of growth of Paracoccus denitrificans: oxygen-limitation and shift from anaerobic nitrate-limination to aerobic succinate-limitation (1983)
    Springer
    Archives of microbiology 135 (1983), S. 229-236 
    Details
    ISSN: 1432-072X
    Keywords: Cytochrome oxidase ; Paracoccus denitrificans ; Growth yields ; Oxidative phosphorylation ; CO-Ligands ; Chemostat ; Proton translocation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. Growth yields and efficiency of energy conservation were the same for aerobic succinate-limited and oxygen-limited cells of Paracoccus denitrificans. 2. A shift from anaerobic nitrate-limitation to aerobic succinatelimitation showed that before and after the shift cells grew with the same capacity of energy conservation. 3. Respiration-driven proton translocation showed the presence of H+-translocating sites 1 and 2, which translocate respectively 2–3 and 4 protons per 2 electrons in oxygen-, anaerobic nitrate-and aerobic succinate-limited cells. 4. Cytochrome spectra and flash-photolysis spectra of oxygen- and nitrate-limited cells gave evidence for the presence of an alternative oxidase, cytochrome a 1, never before recognized in Paracoccus denitrificans. 5. Only a-type cytochromes liganded with CO could be flash-photolysed. No evidence for a functional cytochrome o was found in photolysis experiments. 6. Fast oxidation, before photolysis, of the bc-pool after introduction of oxygen in a CO-liganded sample at-20° to-30° C, indicated the presence of a cytochrome oxidase other than cytochrome a 1 with a very high affinity for oxygen and a low affinity for CO. 7. In photochemical action spectra, light released CO-inhibition of respiration, but the release was independent of the wavelength used (560–610 nm).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00414485
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Reconsideration of the efficiency of energy transduction in Paracoccus denitrificans during growth under a variety of culture conditions (1984)
    Springer
    Archives of microbiology 139 (1984), S. 344-350 
    Details
    ISSN: 1432-072X
    Keywords: Growth yields ; Paracoccus denitrificans ; Oxidative phosphorylation ; Chemostat ; Denitrification ; Proton translocation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. Theoretical overall P/2e- ratios were calculated for growth of Paracoccus denitrificans under a variety of culture conditions on the basis of a growth model and recently published schemes of electron transport and associated proton translocation. 2. Experimental overall P/2e- ratios were calculated, using the specific rate of ATP synthesis determined in cultures grown under aerobic carbon source-limited conditions. 3. The experimental P/2e- was equal to the theoretical P/2e- for aerobic sulphate-limited growth with gluconate or succinate as carbon source, on the assumption that site 1 phosphorylation was completely absent. 4. The experimental and the theoretical P/2e- were similar for growth on nitrate as terminal electron acceptor and gluconate, mannitol or succinate as carbon source, on the assumption that nitrate enters the cell via the electroneutral nitrate-nitrite antiport system. 5. The experimental and theoretical P/2e- were similar for growth on nitrite as terminal electron acceptor and mannitol or succinate as carbon source. 6. The experimental P/2e- was substantially lower than the theoretical P/2e- for aerobic growth with nitrate as nitrogen source and gluconate or mannitol as carbon source. The amount of energy needed for assimilative reduction of nitrate to ammonia was calculated from this difference.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00408377
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Oxidative phosphorylation in Micrococcus denitrificans (1976)
    Springer
    Archives of microbiology 107 (1976), S. 241-247 
    Details
    ISSN: 1432-072X
    Keywords: Oxidative phosphorylation ; Membrane particles ; Continuous culture ; Maintenance energy ; Growth yield ; Micrococcus denitrificans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract P/O ratios were measured in membrane particles obtained from cells of Micrococcus denitrificans, while growing on different carbon sources. The membrane particles obtained from cells growing actively on glucose, succinate, ethanol and propanol as the carbon and energy sources catalyzed oxidative phosphorylation and yielded respective P/O ratios of 1.4, 1.2, 0.8, and 0.5 with NADH, and 0.8, 0.6, 0.6, and 0.5 with succinate as the electron donors. Not such a difference in P/O ratio is observed in intact resting cells grown with different carbon sources. It is concluded that the influence of the carbon source is probably directed towards the efficiency of oxidative phosphorylation in membrane particles and not in the growing cells. For the aerobic carbon source-limited chemostat cultures the following maximum growth yields were determined: 40.2 and 34.2 for succinate and oxgen, 41.7 and 36.5 for malate and oxygen, 81.4 and 39.4 for mannitol and oxygen, and 77.8 and 43.4 for gluconate and oxygen respectively. With a mathematical model (de K waadsteniet et al., in press) the P/O ratio was valued at 1.4–1.7. Y ATP at μ=0.2 was valued at 8.7–10.9; Y ATP max at 9.6–13.2 and m e at 0.6–4.5 for the most precise experiment (gluconate-limited). The calculation of these growth parameters has been discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425334
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Energy conservation during aerobic growth in Paracoccus denitrificans (1977)
    Springer
    Archives of microbiology 112 (1977), S. 25-34 
    Details
    ISSN: 1432-072X
    Keywords: Oxidative phosphorylation ; Proton translocation ; Continuous culture ; Sulphate limitation ; Iron limitation ; Growth yield ; Maintenance energy ; Paracoccus denitrificans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Paracoccus denitrificans was aerobically grown in chemostat culture with succinate or gluconate as carbon source. Due to the presence of two phosphorylation sites in the respiratory chain and the absence of branching, theoretical P/O ratios of 1.71 and 1.82 were calculated for cells growing respectively with succinate and gluconate as carbon source. Using these data, 95% confidence intervals for the P/O ratio were determined, via a mathematical model, at 0.91–1.15 and 1.00–1.37 for sulphate-limited cultures, with respectively succinate and gluconate as carbon source. These results and measurements of P/O ratios in membrane particles and of proton translocation in whole cells have led to the conclusion that site I phosphorylation is affected under sulphate-limited conditions. Under conditions of carbon source-limitation the endogenous →H+/O ratio is about 7–8. Average values of 3.40 and 4.78 were respectively found for sulphate-limited succinate- and gluconate grown cells. For starved cells, oxidizing succinate as exogenous substrate, the →H+/O ratios were determined at about 3–4, independent of the growth limiting factor. It is concluded that the number of protons ejected per pair of electrons per energy-conserving site (→H+/site ratio) is about 3–4, instead of 2 as postulated by the chemiosmotic hypothesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446650
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Growth yields and the efficiency of oxidative phosphorylation during autotrophic growth of Paracoccus denitrificans on methanol and formate (1978)
    Springer
    Archives of microbiology 118 (1978), S. 21-26 
    Details
    ISSN: 1432-072X
    Keywords: Oxidative phosphorylation ; chemostat culture ; pH-auxostat culture ; Growth yield ; Autotrophic growth ; Paracoccus denitrificans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Paracoccus denitrificans was grown aerobically in chemostat or pH-auxostat cultures with methanol or formate as the limiting carbon source. The maximum growth yields (expressed in g biomass/mole), determined in methanol-limited cultures, on methanol, oxygen and carbon-dioxide were 13.4, 15.5 and 24.8 respectively. The maximum growth yields, determined in formate-limited cultures, on formate and oxygen were 2.9 and 10.5 respectively. Elemental analysis of these cells yielded a cell formula of C6H10.8N1.5O2.9. With the help of the known elemental cell composition an equation for material balances could be drawn up. The calculated yields on oxygen and CO2 (Y O 2 and Y CO 2) were in good agreement with the experimental values. Autotrophically grown cells on methanol possess three active energy conserving sites in the electron-transport chain. The overall P/O ratio (the amount of adenosine triphosphate (ATP) synthesized per atom oxygen consumed) is calculated to be 2.05 with the matching Y ATP max value of 3.8, which is lower than the theoretical value of 6.5. With only 2 phosphorylation sites impossible Y ATP max values would result. Autotrophic growth on formate yielded cells in the possesion of only two active energy conserving sites, most probably sites 1 and 2. Formate crosses the cytoplasmic membrane as free acid, which is equivalent to co-transport with one proton. Therefore transport of formate is energy requiring. With →H+/site ratios of 2 or 3 respectively 0.5 or 0.33 moles of ATP are necessary to transport 1 mole of formate. Consequently the P/O ratio in formate-grown cells is respectively 1.5 or 1.67 with the matching Y ATP max values of 3.1 or 3.5. Therefore during autotrophic growth on methanol and formate the same amount of adenosine triphosphate is necessary to synthesize 1 g of biomass. The 95% confidence intervals of the Y ATP max values overlap completely. The found Y ATP max is 50–60% of the theoretical value as was found for heterotrophic growth of Paracoccus denitrificans. We propose that metabolism in Paracoccus denitrificans is regulated on the level of phosphorylation in the site 1 and the site 3 region of the electron-transport chain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00406069
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...