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
Filter
  • 1985-1989  (14)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    On-Line Chromatographic Analysis and Fermenter State Characterization of Butanol/Acetone Fermentations (1986)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 469 (1986), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1986.tb26512.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Formate transport, growth inhibition and the membrane protonmotive force in two methylotrophs (T15 and L3) (1987)
    Springer
    Applied microbiology and biotechnology 26 (1987), S. 70-77 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Formate transport and the effect of formate on growth and the membrane protonmotive force were studied in two ribulose-monophosphate-type obligate methylotrophs (bacterial strains T15 and L3). Formate was accumulated very fast by the membrane ΔpH according to the general transport mechanism of short-chain organic acids. Formate accumulation was reduced or abolished by a number of factors (protonophores, high extracellular pH, cell-starvation conditions) that reduced or abolished the ΔpH. Formate transport was accompanied by removal of protons from the medium by the cells. Since protons are released by the cells upon substrate oxidation, the stoichiometry of proton uptake upon formate transport could not be directly determined, although data suggest that formate is cotransported with one proton. The net rate of proton removal from the medium by the cells due to formate transport and oxidation increased with increasing formate concentrations or decreasing medium-pH values. The membrane protonmotive force of strain T15 was also studied as a function of the pH. High formate concentrations (of 100 to 400 mM) reduced the membrane ΔpH by ca. 20 to 60% and the growth rate by ca. 20 to 100% for both strains but to a different extent. For example, 400 mM formate inhibited growth by ca. 60% in strain T15 and by 100% in strain L3. The nature of growth inhibition by formate is discussed in some detail.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00282151
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Carbon monoxide gasing leads to alcohol production and butyrate uptake without acetone formation in continuous cultures ofClostridium acetobutylicum (1986)
    Springer
    Applied microbiology and biotechnology 24 (1986), S. 159-167 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary When continuous, steady-state, glucose-limited cultures ofClostridium acetobutylicum were sparged with CO, the completely or almost completely acidogenic fermentations became solventogenic. Alcohol (butanol and ethanol) and lactate production at very high specific production rates were initiated and sustained without acetone, and little or no acetate and butyrate formation. In one fermentation, strong butyrate uptake without acetone formation was observed. Growth could be sustained even with 100% inhibition of H2 formation. Although CO gasing inhibited growth up to 50%, and H2 formation up to 100%, it enhanced the rate of glucose uptake up to 300%. TheY ATP was strongly affected and mostly reduced with respect to its steady-state value. The results support the hypothesis that solvent formation is triggered by an altered electron flow.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01982561
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Comparison between in vivo and in vitro enzyme activities in continuous and batch fermentations of Clostridium acetobutylicum (1989)
    Springer
    Applied microbiology and biotechnology 30 (1989), S. 585-595 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary In vitro activities of key enzymes and related parameters (ATP and ADP concentrations, intracellular pH (pH i ), cell volume and the transmembrane ΔpH) in various continuous and batch fermentations of Clostridium acetobutylicum were studied in order to investigate the regulation (genetic vs. enzyme level) of the solventogenesis process. In vitro activities varied significantly among an acidogenic (glucose limited) and three solventogenic (an iron limited, a CO gassed and a biomass recycle) continuous fermentations. However, in vitro enzyme activities did not correlate with in vivo specific production rates in continuous cultures indicating that solvent formation is regulated primarily at the enzyme level. Carbon monoxide (CO) gassing of an acidogenic continuous culture resulted in butyrate uptake without acetone formation due to inactivation of the acetoacetate decarboxylase by CO. In continuous, and to some extent in batch cultures, butyrate can be taken up via the reversal of the butyrate kinase and phosphotransbutyrylase pathway. Solvent formation in batch fermentations is both a result of enzyme induction and regulation. Acetone formation and the induction of acetoacetate decarboxylase occur simultaneously whereas both alcohol dehydrogenases are induced several hours before initiation of alcohol production. Finally, the levels of intracellular and related cell parameters (pH i , ΔpH, ATP and ADP concentrations) are discussed and related to the possible mechanisms of solventogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00255364
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Increased levels of ATP and NADH are associated with increased solvent production in continuous cultures of Clostridium acetobutylicum (1989)
    Springer
    Applied microbiology and biotechnology 30 (1989), S. 450-459 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Levels of intracellular NAD, NADH, ADP, and ATP were measured in batch and continuous cultures of Clostridium acetobutylicum. ATP levels during glucose-sufficient (non-glucose limited), solvent-producing steady states were five to eight times as high as in glucose-limited (acidogenic) steady state cultures (4.8 μmole/g versus 0.9 μmole/g). NADH was also higher in glucose-sufficient cultures, although the increase was not as pronounced as with ATP. When glucose-limited cultures were sparged with CO, the resulting shift to solvent production was accompanied by three- or four-fold increases in NADH and ATP levels. In batch cultures, NADH and ATP levels were relatively high at all times compared to levels in continuous cultures. Although the levels of these nucleotides showed systematic trends during normal batch fermentations, there was no significant change with the onset of solvent production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00263849
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Enzymes limiting butanol and acetone formation in continuous and batch cultures of Clostridium acetobutylicum (1989)
    Springer
    Applied microbiology and biotechnology 31 (1989), S. 435-444 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The formation of butanol in continuous cultures of Clostridium acetobutylicum is regulated at the genetic level via expression of butyraldehyde dehydrogenase since increased in vitro activities of this key enzyme are associated with increased in vivo butanol formation rates in both acidogenic and solventogenic fermentations. Addition of glucose, butyric acid and carbon monoxide results in induction of butyraldehyde dehydrogenase. The production of acetone in continuous fermentation is also controlled at the genetic level through expression of coenzyme A (CoA)-transferase; this enzyme is induced by glucose. Carbon monoxide inactivates acetoacetate decarboxylase. In controlled-pH batch fermentation solventogenesis does not correlate with in vitro activities of butyraldehyde dehydrogenase. Instead, initiation of alcohol formation is accompanied by increased activities of both reduced nicotine adenine dinucleotide (NADH)- and reduced nicotine adenine dinucleotide phosphate (NADPH)-specific alcohol dehydrogenases. The production of acetone in batch fermentation is regulated at the genetic level through combined induction of both CoA-transferase and acetoacetate decarboxylase. These two enzymes are not detected in either batch or continuous culture at or above pH 6.0. This finding explains the inability of the cells to produce acetone at elevated culture pH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00270772
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Carbon monoxide gasing leads to alcohol production and butyrate uptake without acetone formation in continuous cultures ofClostridium acetobutylicum (1986)
    Springer
    Applied microbiology and biotechnology 24 (1986), S. 159-167 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary When continuous, steady-state, glucose-limited cultures ofClostridium acetobutylicum were sparged with CO, the completely or almost completely acidogenic fermentations became solventogenic. Alcohol (butanol and ethanol) and lactate production at very high specific production rates were initiated and sustained without acetone, and little or no acetate and butyrate formation. In one fermentation, strong butyrate uptake without acetone formation was observed. Growth could be sustained even with 100% inhibition of H2 formation. Although CO gasing inhibited growth up to 50%, and H2 formation up to 100%, it enhanced the rate of glucose uptake up to 300%. TheY ATP was strongly affected and mostly reduced with respect to its steady-state value. The results support the hypothesis that solvent formation is triggered by an altered electron flow.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00938789
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Solventogenesis in Clostridium acetobutylicum fermentations related to carboxylic acid and proton concentrations (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 32 (1988), S. 843-852 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The mechanism primarily implicated in the solventogenesis process in batch fermentations of Clostridium acetobutylicum is examined in considerable detail. A variety of fermentations with or without pH control in the pH range of 3.7-6 have been carried out in order to examine which of a host of suspect parameters correlate with the initiation of solventogenesis. The parameters that did not correlate are the external (pH0) and intracellular (pHi) pH, and ΔpH, and the external or intracellular butyrate and acetate concentrations. Undissociated butyric acid (UBA) correlated well with the initiation of solventogenesis. A linear relationship between UBA and butanol concentrations was found at the onset of solventogenesis in all fermentations examined. The intercept of this linear relationship was 6-13mM UBA for the pH0 range of 3.7-5 and approximately zero for pH0 at or above 6. The required minimal UBA was interpreted as a dependency of the solventogenesis process on both H+ and butyrate concentrations. Undissociated acetic acid was found not to correlate with the initiation of solventogenesis. Addition of acetoacetate (AA) and propionate enhanced the effect of UBA on the solventogenesis process. The action of a nonmetabolizable (FCCP) and a metabolizable (AA) uncoupler on the ΔpH, pH0, pHi, and solventogenesis were also studied in order to gain further understanding of the solventogenesis mechanism.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260320702
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The effect of pH on nitrogen supply, cell lysis, and solvent production in fermentations of Clostridium acetobutylicum (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 27 (1985), S. 681-694 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In batch fermentations of C. acetobutylicum, with 5 g/L yeast extract and 50mM glucose, the ratio of ammonium to glucose affected solvent production when the pH was left to vary uncontrolled from 4.5 to 3.65. High solvent production was observed for a low ratio. When the pH was controlled at 4.5, only acids were produced for all ratio values. At a low ammonium-to-glucose ratio, solvents were produced when the pH was controlled at 3.7. Acids only were produced for a low ratio value at pH 4.0 or for a high ratio value at pH 3.7. In continuous cultures, mostly acids were produced under glucose limitation, but solvents were produced under nitrogen limitation. It was concluded that the nitrogen availability controls solvent production and that the pH affects the availability of organic nitrogen. Biomass autolysis at the stationary phase of batch cultures was reversibly inhibited at pH values less than 3.8. In batch fermentations, the overall molar growth yields on ATP (YATP) varied from 5.5 to 9.0 and the transient yields from 5.5 to 15.5. In continuous cultures, the YATP values varied from 5.5 to 14.7 under glucose limitation, and from 6.1 to 9.3 under nitrogen limitation. The YATP depended on the ammonium to glucose ratio and the culture pH, but did not show the usual dependence on the specific growth rate in batch cultures. The experiments seem to confirm the hypothesis that solvent production is controlled by the demand and availability of ATP.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260270518
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Gas chromatography and gateway sensors for on-line state estimation of complex fermentations (butanol-acetone fermentation) (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 27 (1985), S. 1246-1257 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A fermentation system has been designed to demonstrate the use of gas chromatography (GC) for on-line monitoring of the butanol-acetone and other complex saccharolytic fermentations. Tangential flow ultrafiltration was used to sterilely and continuously obtain a cell-free filtrate from the fermentation broth for on-line GC analysis of butanol, butyrate, acetate, acetone, ethanol, and acetoin. The liquid injection system consists of a phosphoric acid contactor, a slider-type injection valve, and a heater to address the difficulties (ghosting) encountered in the analysis of carboxylic acids. The fermentation headspace gas was also analyzed by on-line GC for nitrogen and carbon dioxide, while hydrogen was measured by difference. Raw chromatographic data were analyzed by a chromatography data system. Both raw and processed data were transmitted to a VAX 11/750 computer for further processing (using the fermentation equation) and archiving. The fermentation equation, which has recently been derived and tested on completed fermentation data, was also found to be valid during transient fermentations and thus useful as a gateway sensor for calculating various fermentation parameters on-line. Such parameters include glucose concentration and gas composition, as well as a number of unobservable parameters (such as YATP, excess ATP, and NAD reduced by FdH2), which characterize the state of the fermentation.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260270821
    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...