% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@TECHREPORT{Schmid:845599,
      author       = {Schmid, U.},
      title        = {{X}ylosevergärung mit dem thermophilen {B}akterium
                      {T}hermoanaerobacter {F}innii},
      volume       = {2168},
      number       = {Juel-2168},
      address      = {Jülich},
      publisher    = {Kernforschungsanlage Jülich, Verlag},
      reportid     = {FZJ-2018-02819, Juel-2168},
      series       = {Berichte der Kernforschungsanlage Jülich},
      pages        = {129 p.},
      year         = {1987},
      abstract     = {This study presents results of the fermentation of xylose
                      with the thermophilic bacterium $\textit{Thermoanaerobacter
                      finnii}$, especially the effects of substrate concentration
                      on end product formation. 1. Comparative studies on
                      differences in morphological and physiological features,
                      GC-content and DNA-homologies of $\textit{AKO-1}$ with other
                      thermophilic bacteria were performed. The newly isolated
                      bacterium $\textit{AKO-1}$ is closely related to the
                      nonsporeformer $\textit{Thermoanaerobacter ethanolicus}$. It
                      was classified as $\textit{Thermoanaerobacter finnii}$. 2.
                      Fermentation of xylose yields ethanol, acetate, L-lactate,
                      H$_{2}$ and CO$_{2}$ in varying amounts depending on the
                      substrate concentration. Batch fermentations with increasing
                      xylose concentrations higher than 66 mM resulted in a
                      decrease of the ethanol yield from 1.25 to 0.85 mol/mol
                      xylose (maximum ethanol yield is 1.66 mol/mol xylose) and in
                      an increase in lactate formation. Fed-batch-fermentations
                      with stationary concentrations of xylose between 20 and 60
                      mM lead to a very low lactate production (2mM), so that from
                      200 mM of xylose 230 mM ethanol were produced, corresponding
                      to 70\% of the maximal achievable yield. Increasing xylose
                      consumption rates lead to increasing lactate formation rates
                      (from 0.04 to 1.52 mmol/ 1-h), whereas the ethanol formation
                      rate remained largely constant (5.2 and 4.6 mmol/ 1-h
                      respectively). The inhibitory effect of ethanol on growth
                      and product formation was circumvented by continous removal
                      of the produced alcohol from the culture broth by an inert
                      gas stream. That way xylose consumption could be raised from
                      200 to 400 mM. 3. Enzymatic studies showed that $\textit{T.
                      finnii}$ catabolises xylose to xylulose and
                      xylulose-5-phosphate which is then degraded to pyruvate via
                      the pentosephosphate pathway and glycolysis.
                      Fructose-1,6-bisphosphate has been shown to be an activator
                      of the lactate-dehydrogenase and causes a decrease of the
                      K$_{M}$ values for NADH and pyruvate. The
                      lactate-dehydrogenase has a pH-optimum at pH7.0 and is
                      completely inhibited by 2 mM NADPH. The activity of the
                      ferredoxin-NAD-reductase (1.1 U/mg protein) was 10 times
                      higher than the ferredoxin-NADP-reductase activity. For the
                      first time a transhydrogenase activity (0,9 U/mg protein)
                      was detected in thermophilic ethanol producing bacteria,
                      which transfered electrons from NADH to NADP. The activity
                      of the acetaldehyde-dehydrogenase in $\textit{T. finnii}$
                      was very low (0.03 U/mg protein) compared to the other
                      catabolic enzyme activities. 4. The intracellular pyridine
                      nucleotide levels were between 1.5 to 4 nmol NADPH/mg dry
                      weight and 0.6 to 2 nmol NADH/mg dry weight, whereas the NAD
                      and NADP levels reached only 0.1 to 1.2 and 0.5 to 1.2
                      nmol/mg dry weight, respectively. The intracellular
                      fructose-1,6-bisphosphate concentrations ranged between 1.2
                      and 8.4 nmol/mg dry weight. These fructose-1,6-bisphosphate
                      levels are sufficient for complete activation of the
                      lactate-dehydrogenase, so that presumably the
                      lactateformation depends $\underline{not}$
                      $\underline{only}$ on the intracellular
                      fructose-1,6-bisphosphate level, but also on the
                      intracellular concentration of pyruvate.},
      cin          = {PRE-2000},
      cid          = {I:(DE-Juel1)PRE2000-20140101},
      pnm          = {899 - ohne Topic (POF3-899)},
      pid          = {G:(DE-HGF)POF3-899},
      typ          = {PUB:(DE-HGF)3 / PUB:(DE-HGF)29},
      url          = {https://juser.fz-juelich.de/record/845599},
}