ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    H2: heterodisulfide oxidoreductase, a second energy-conserving system in the methanogenic strain Gö1 (1991)
    Springer
    Archives of microbiology 155 (1991), S. 272-277 
    Details
    ISSN: 1432-072X
    Keywords: Archaebacteria ; Methanogenesis ; Membranes ; Proton translocation ; ATP synthesis ; Electrontransport phosphorylation ; Hydrogenase ; F420 ; Heterodisulfide reduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Washed everted vesicles of the methanogenic bacterium strain Gö1 catalyzed an H2-dependent reduction of the heterodisulfide of HS-CoM (2-mercaptoethanesulfonate) and HS-HTP (7-mercaptoheptanoylthreonine phosphate) (CoM-S-S-HTP). This process was independent of coenzyme F420 and was coupled to proton translocation across the cytoplasmic membrane into the lumen of the everted vesicles. The maximal H+/CoM-S-S-HTP ratio was 2. The tranmembrane electrochemical gradient thereby generated was shown to induce ATP synthesis from ADP+Pi, exhibiting a stoichiometry of 1 ATP synthesized per 2 CoM-S-S-HTP reduced (H+/ATP=4). ATP formation was inhibited by the uncoupler 3,5-di-tert-butyl-4-hydroxy-benzylidene-malononitrile (SF 6847) and by the ATP synthase inhibitor N,N′-dicyclohexylcarbodiimide (DCCD). This energy-conserving system showed a stringent coupling. The addition of HS-CoM and HS-HTP at 1 mM each decreased the heterodisulfide reductase activity to 50% of the control. Membranes from Methanolobus tindarius showed F420H2-dependent but no H2-dependent heterodisulfide oxidoreductase activity. Neither of these activities was detectable in membranes of Methanococcus thermolithotrophicus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00252211
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Spectroscopic and potentiometric characterization of cytochromes in two Sporomusa species and their expression during growth on selected substrates (1993)
    Springer
    Archives of microbiology 159 (1993), S. 189-196 
    Details
    ISSN: 1432-072X
    Keywords: Cytochromes ; Redox difference spectroscopy ; Midpoint potential ; Betaine ; Formate ; Acetoin ; Acetyl-CoA pathway ; Sporomusa ovata ; Sporomusa sphaeroides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The homoacetogenic bacteria Sporomusa ovata and Sporomusa sphaeroides were grown on betaine, betaine + formate, and acetoin in the absence of carbon dioxide, and the formation of membrane-bound cytochromes was determined. In S. sphaeroides, the growth substrate had little influence on the expression of cytochromes. In contrast, membranes from betaine-or acetoin-grown S. ovata cells had an 11-or 3-fold higher cytochrome b content than cells grown on betaine + formate. The cytochrome c content was reduced below the detection level after growth on the latter two substrates. The cytochromes in the membranes of S. sphaeroides and S. ovata were characterized by low-temperature difference spectroscopy, hemochrome difference spectroscopy, and redox potentiometry. Membranes of S. ovata were shown to contain two b-type cytochromes with Em,7=-153±10 mV and Em,7=-226±14 mV and two c-type cytochromes with Em,7=-86±6 mV and Em,7=-265±10 mV. In S. sphaeroides also two b-type cytochromes with Em,7=-165±7 mV and Em,7=-241±2 mV and two c-type cytochromes with Em,7=-101±4 mV and Em, 8.5=-338±9 mV could be distinguished. Cell extracts of S. sphaeroides were shown to contain all the enzymes of the acetyl-CoA (Wood) pathway. The degradation pathways of the substrates tested and the possible role of the cytochromes are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00250281
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Effect of trimethylamine on acetate utilization by Methanosarcina barkeri (1982)
    Springer
    Archives of microbiology 133 (1982), S. 230-235 
    Details
    ISSN: 1432-072X
    Keywords: Methanosarcina barkeri ; Acetate ; Trimethylamine ; Methanogenesis ; Acetate oxidation ; Assimilation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During growth of Methanosarcina barkeri strain Fusaro on a mixture of trimethylamine and acetate, methane production and acetate consumption were biphasic. In the first phase trimethylamine (33 mmol x l-1) was depleted and some acetate (11–14 from 50 mmol x l-1) was metabolized simultaneously. In the second phase the remaining acetate was cleaved stoichiometrically into CH4 and CO2. Kinetic experiments with (2-14C)acetate revealed that only 2.5% of the methane produced in the first phase originated from acetate: 18% of the acetate metabolized was cleaved into CH4 and CO2, 23% of the acetate was oxidized, and 55% was assimilated. Methane produced from CD3−COOH in the first phase consisted of CD2H2 and CD3H in a ratio of 1:1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00415007
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Transformation of tetrachloroethylene to trichloroethylene by homoacetogenic bacteria (1994)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 123 (1994), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Eight homoacetogenic strains of the genera Acetobacterium, Clostridium and Sporomusa were tested for their ability to dechlorinate tetrachloroethylene (perchloroethene, PCE). Of the organisms tested only Sporomusa ovata was able to reductively dechlorinate PCE with methanol as an electron donor. Resting cells of S. ovata reductively dechlorinated PCE at a rate of 9.8 nmol h−1 (mg protein)−1 to trichloroethylene (TCE) as the sole product. The dechlorination activity depended on concomitant acetogenesis from methanol and CO2. Cell-free extracts of S. ovata, Clostridium formicoaceticum, Acetobacterium woodii, and the methanogenic bacterium Methanolobus tindarius transformed PCE to TCE with Ti(III) or carbon monoxide as electron donors. Corrinoids were shown in S. ovata to be involved in the dechlorination reaction of PCE to TCE as evident from the reversible inhibition with propyl iodide. Rates of dechlorination followed a pseudo-first-order kinetic.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6968.1994.tb07224.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Oxidation of trimethylamine to the level of formaldehyde by Methanosarcina barkeri is dependent on the protonmotive force (1987)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 43 (1987), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The conversion of trimethylamine to methane, carbon dioxide and ammonia as catalyzed by cell suspensions of Methanosarcina barkeri was coupled to the generation of a protonmotive force and to the synthesis of ATP. Methanogenesis as well as ATP formation and protonmotive force generation was abolished by the uncoupler tetrachloro-salicylanilide (TCS). Inhibition of methane formation was reversed by addition of formaldehyde, which was predominantly oxidized to carbon dioxide, whereas trimethylamine was predominantly reduced to methane and ammonia under these conditions. Cell extracts of M. barkeri were unable to convert trimethylamine to methane, carbon dioxide and ammonia independent from the presence or absence of ATP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6968.1987.tb02120.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Protonmotive force-driven synthesis of ATP during methane formation from molecular hydrogen and formaldehyde or carbon dioxide in Methanosarcina barkeri (1984)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 24 (1984), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Methane formation from formaldehyde and H2 or from carbon dioxide and H2, as performed by cell suspensions of Methanosarcina barkeri, was coupled to ATP synthesis. In correspondence with this, methane formation was inhibited by N,N′-dicyclohexylcarbodiimide (DCCD), which at the same time, caused a decrease of the intracellular ATP concentration but only a slow decrease of the membrane potential. Addition of the uncoupler tetrachlorosalicylanilide (TCS) led to a relief of the inhibition of methane formation from CH2O + H2, but not from CO2+ H2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6968.1984.tb01253.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The growth of the flavonoid-degrading intestinal bacterium, Eubacterium ramulus, is stimulated by dietary flavonoids in vivo (2002)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology ecology 40 (2002), S. 0 
    Details
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: A human study was performed to investigate the influence of different dietary flavonoids on the faecal population of the flavonoid-degrading bacterium Eubacterium ramulus. Twenty-eight healthy subjects, divided into five groups, consumed for 6 days a flavonoid-free diet. On day 4 of this intervention period the study participants ingested a single dose of quercetin (14 mg kg−1 body mass (bm)), rutin (pure or as buckwheat leaves, 28 mg kg−1 bm) or a placebo. During the first 3 days of the intervention period the total faecal flora decreased by 61–88% and the population of E. ramulus by 40–75%. The oral intake of the flavonoids resulted in a dramatic increase in the faecal E. ramulus population. The relative proportion of E. ramulus rose from minimally 0.2% (on day 1) to maximally 6.9% of the total flora on day 8. The faecal concentrations of degradational products were highly variable but reflected the bacterial breakdown of the flavonoids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6941.2002.tb00957.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Sodium bioenergetics in methanogens and acetogens (1990)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 87 (1990), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Recent investigations with Methanosarcina barkeri elucidated the role of sodium ions in the energy metabolism of methanogenic bacteria and provided evidence for a novel mechanism of energy transduction with Na+ as the coupling ion. During methanogenesis from methanol, an eletrochemical sodium gradient generated by a Na+/H+ antiporter is used as the driving force for the thermodynamically unfavourable oxidation of methanol to the formal redox level of formaldehyde. During methanogenesis from H2+ CO2, the reverse reaction, the reduction of formaldehyde to the level of methanol, is accompanied by a primary, electron transport-driven sodium extrusion. Acetogenesis from H2+ CO2 as carried out by Acetobacterium woodii is a sodium-dependent process and is accompanied by the generation of a transmembrane sodium gradient with the reduction of formaldehyde to the level of methanol as the sodium-dependent step.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6968.1990.tb04939.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Energy transduction in vesicles of the methanogenic strain Gö1 (1990)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 87 (1990), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Everted vesicles of the methanogenic strain Gö1 synthesized ATP in response to methanogenesis from methyl-coenzyme M and H2. Simultaneously, a transmembrane pH gradient (ΔpH) was generated as evident from fluorescence quenching of acridine orange. Protonophorous uncouplers prevented ΔpH generation and ATP synthesis, but did not affect methanogenesis. The ATP synthase inhibitor diethylstilbestrol (DES) inhibited ATP synthesis but had no effect on methanogenesis and on ΔpH formation, indicating the essential role of the transmembrane proton potential in ATP synthesis. Progress has also been made in assigning specific functions to membrane components in methanogenesis from methyl-CoM and H2. Separation of cell extracts into cytoplasmic and membrane fraction revealed an essential role of membrane-bound components in electron transfer: methanogenesis catalyzed by the cytoplasmic fraction from strain Gö1 was stimulated several fold by membranes from various methanogens. This stimulation was prevented if the membranes had been treated with oxidants (O2, K3[Fe(CN)6]) or SH reagents (Ag+, p-chloromercuribenzoate, iodoacetamide) pointing to the involvement of functional SH groups in methanogenesis from methyl-CoM and H2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6968.1990.tb04938.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The F420H2-dehydrogenase from Methanolobus tindarius: cloning of the ffd operon and expression of the genes in Escherichia coli (1999)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 170 (1999), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The membrane-bound F420H2-dehydrogenase from the methylotrophic methanogen Methanolobus tindarius oxidizes reduced coenzyme F420 and feeds the electrons into an energy-conserving electron transport chain. Based on the N-terminal amino acid sequence of the 40-kDa subunit of F420H2-dehydrogenase the corresponding gene ffdB was detected in chromosomal DNA of M. tindarius. Sequence analysis, primer extension, and RT-PCR experiments indicated that ffdB is part of an operon harboring three additional open reading frames (ffdA, ffdC, ffdD). The corresponding mRNA transcript and transcription start sites were determined. All four genes could be heterologously expressed in Escherichia coli.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6968.1999.tb13399.x
    Location Call Number Expected 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...