D-xylose fermentation by Fusarium oxysporum and other fungi

Dissertation

Maija-Liisa Suihko

Research output: ThesisDissertationCollection of Articles

Abstract

Xylose fermentation was studied in order to provide the basis for an economically feasible ethanol production process using sugars derived from biomass.During the study 67 different yeast strains and 27 Fusarium strains were tested.The best strain for xylose fermentation was Fusarium oxysporum VTT-D-80134, which was selected for more extensive experiments.It was found that xylose metabolism in F. oxysporum starts by reduction of xylose to xylitol followed by oxidation to xylulose, yielding ultimately ethanol and carbon dioxide.Yields almost as high as the theoretical maximum (0.44 _ 0.50 gg-l) were obtained from xylose (50 gl~l) in semianaerobic shake flask fermentations in six days.In optimized conditions, involving strict control of oxygen supply, the fermentation time was shortened to four days.The ethanol yield was 0.43 gg-l based on added xylose.The maximal specific ethanol production rate was 0.14 gg-lh-l~ F. oxysporum was able to ferment all the sugars present in birchwood hydrolyzates, except L-a rabinose and L-rhamnose, which were used only for aerobic growth.Xylan was not fermented directly to ethanol due to the inability of the fungus to hydrolyze the Polymer to xylose. The main sugars, D-glucose and D-xylose, were fermented successively without diauxia.Sugar concentrations up to 200 gl~ caused only a slight decrease in the fermentation rate.Ethanol concentrations below 45 gl~l did not inhibit the fermentation.Inhibition was, however, caused by some compounds present in wood hydrolyzates.Continuous fermentation by immobilized F. oxysporum cells was unsuccessful due to the growth of mycelium out from the beads. however, a continuous process with free cells appeared more promising.
Original languageEnglish
QualificationDoctor Degree
Awarding Institution
  • University of Helsinki
Award date10 Aug 1984
Place of PublicationEspoo
Publisher
Print ISBNs951-38-2062-9
Publication statusPublished - 1984
MoE publication typeG5 Doctoral dissertation (article)

Fingerprint

Fusarium oxysporum
xylose
fermentation
fungi
ethanol
sugars
ethanol production
liquid state fermentation
continuous fermentation
xylulose
xylitol
rhamnose
aerobiosis
xylan
Fusarium
mycelium
polymers
carbon dioxide
cells
oxidation

Keywords

  • xylose
  • Fusarium
  • fermentation
  • fuel ethanol
  • ethyl alcohol

Cite this

Suihko, M-L. (1984). D-xylose fermentation by Fusarium oxysporum and other fungi: Dissertation. Espoo: VTT Technical Research Centre of Finland.
Suihko, Maija-Liisa. / D-xylose fermentation by Fusarium oxysporum and other fungi : Dissertation. Espoo : VTT Technical Research Centre of Finland, 1984. 74 p.
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abstract = "Xylose fermentation was studied in order to provide the basis for an economically feasible ethanol production process using sugars derived from biomass.During the study 67 different yeast strains and 27 Fusarium strains were tested.The best strain for xylose fermentation was Fusarium oxysporum VTT-D-80134, which was selected for more extensive experiments.It was found that xylose metabolism in F. oxysporum starts by reduction of xylose to xylitol followed by oxidation to xylulose, yielding ultimately ethanol and carbon dioxide.Yields almost as high as the theoretical maximum (0.44 _ 0.50 gg-l) were obtained from xylose (50 gl~l) in semianaerobic shake flask fermentations in six days.In optimized conditions, involving strict control of oxygen supply, the fermentation time was shortened to four days.The ethanol yield was 0.43 gg-l based on added xylose.The maximal specific ethanol production rate was 0.14 gg-lh-l~ F. oxysporum was able to ferment all the sugars present in birchwood hydrolyzates, except L-a rabinose and L-rhamnose, which were used only for aerobic growth.Xylan was not fermented directly to ethanol due to the inability of the fungus to hydrolyze the Polymer to xylose. The main sugars, D-glucose and D-xylose, were fermented successively without diauxia.Sugar concentrations up to 200 gl~ caused only a slight decrease in the fermentation rate.Ethanol concentrations below 45 gl~l did not inhibit the fermentation.Inhibition was, however, caused by some compounds present in wood hydrolyzates.Continuous fermentation by immobilized F. oxysporum cells was unsuccessful due to the growth of mycelium out from the beads. however, a continuous process with free cells appeared more promising.",
keywords = "xylose, Fusarium, fermentation, fuel ethanol, ethyl alcohol",
author = "Maija-Liisa Suihko",
year = "1984",
language = "English",
isbn = "951-38-2062-9",
series = "Publications / Technical Research Centre of Finland",
publisher = "VTT Technical Research Centre of Finland",
number = "17",
address = "Finland",
school = "University of Helsinki",

}

Suihko, M-L 1984, 'D-xylose fermentation by Fusarium oxysporum and other fungi: Dissertation', Doctor Degree, University of Helsinki, Espoo.

D-xylose fermentation by Fusarium oxysporum and other fungi : Dissertation. / Suihko, Maija-Liisa.

Espoo : VTT Technical Research Centre of Finland, 1984. 74 p.

Research output: ThesisDissertationCollection of Articles

TY - THES

T1 - D-xylose fermentation by Fusarium oxysporum and other fungi

T2 - Dissertation

AU - Suihko, Maija-Liisa

PY - 1984

Y1 - 1984

N2 - Xylose fermentation was studied in order to provide the basis for an economically feasible ethanol production process using sugars derived from biomass.During the study 67 different yeast strains and 27 Fusarium strains were tested.The best strain for xylose fermentation was Fusarium oxysporum VTT-D-80134, which was selected for more extensive experiments.It was found that xylose metabolism in F. oxysporum starts by reduction of xylose to xylitol followed by oxidation to xylulose, yielding ultimately ethanol and carbon dioxide.Yields almost as high as the theoretical maximum (0.44 _ 0.50 gg-l) were obtained from xylose (50 gl~l) in semianaerobic shake flask fermentations in six days.In optimized conditions, involving strict control of oxygen supply, the fermentation time was shortened to four days.The ethanol yield was 0.43 gg-l based on added xylose.The maximal specific ethanol production rate was 0.14 gg-lh-l~ F. oxysporum was able to ferment all the sugars present in birchwood hydrolyzates, except L-a rabinose and L-rhamnose, which were used only for aerobic growth.Xylan was not fermented directly to ethanol due to the inability of the fungus to hydrolyze the Polymer to xylose. The main sugars, D-glucose and D-xylose, were fermented successively without diauxia.Sugar concentrations up to 200 gl~ caused only a slight decrease in the fermentation rate.Ethanol concentrations below 45 gl~l did not inhibit the fermentation.Inhibition was, however, caused by some compounds present in wood hydrolyzates.Continuous fermentation by immobilized F. oxysporum cells was unsuccessful due to the growth of mycelium out from the beads. however, a continuous process with free cells appeared more promising.

AB - Xylose fermentation was studied in order to provide the basis for an economically feasible ethanol production process using sugars derived from biomass.During the study 67 different yeast strains and 27 Fusarium strains were tested.The best strain for xylose fermentation was Fusarium oxysporum VTT-D-80134, which was selected for more extensive experiments.It was found that xylose metabolism in F. oxysporum starts by reduction of xylose to xylitol followed by oxidation to xylulose, yielding ultimately ethanol and carbon dioxide.Yields almost as high as the theoretical maximum (0.44 _ 0.50 gg-l) were obtained from xylose (50 gl~l) in semianaerobic shake flask fermentations in six days.In optimized conditions, involving strict control of oxygen supply, the fermentation time was shortened to four days.The ethanol yield was 0.43 gg-l based on added xylose.The maximal specific ethanol production rate was 0.14 gg-lh-l~ F. oxysporum was able to ferment all the sugars present in birchwood hydrolyzates, except L-a rabinose and L-rhamnose, which were used only for aerobic growth.Xylan was not fermented directly to ethanol due to the inability of the fungus to hydrolyze the Polymer to xylose. The main sugars, D-glucose and D-xylose, were fermented successively without diauxia.Sugar concentrations up to 200 gl~ caused only a slight decrease in the fermentation rate.Ethanol concentrations below 45 gl~l did not inhibit the fermentation.Inhibition was, however, caused by some compounds present in wood hydrolyzates.Continuous fermentation by immobilized F. oxysporum cells was unsuccessful due to the growth of mycelium out from the beads. however, a continuous process with free cells appeared more promising.

KW - xylose

KW - Fusarium

KW - fermentation

KW - fuel ethanol

KW - ethyl alcohol

M3 - Dissertation

SN - 951-38-2062-9

T3 - Publications / Technical Research Centre of Finland

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Suihko M-L. D-xylose fermentation by Fusarium oxysporum and other fungi: Dissertation. Espoo: VTT Technical Research Centre of Finland, 1984. 74 p.