Bioactive components of fermented soya beans effective against diarrhoea-associated bacteria

P.J. Roubos-van den Hil

Research output: Thesisinternal PhD, WUAcademic

Abstract

Tempe is a fermented food, obtained by fungal fermentation of soya beans. During the processing specific flavour, texture and nutritional properties are achieved. Previous research has indicated that tempe reduced the incidence and severity of diarrhoea. In this thesis the bioactive effects of tempe on diarrhoea-associated bacteria are described.
Tempe appeared to be antibacterial against Bacillus cereus cells and spores, but not against enterotoxigenic Escherichia coli (ETEC). Nevertheless, tempe was found to inhibit the adhesion of ETEC to intestinal epithelial cells.
Experiments showed that the inhibition of adhesion was caused by an interaction between ETEC and tempe extracts. A range of ETEC strains was shown to be sensitive for the anti-adhesive component, making the bioactivity of broader interest for applications in feed matrices.
Furthermore, several substrates (legumes and cereals) were fermented and all fermented legumes tested were equally bioactive as the fermented soya beans, whereas the fermented cereals were not active. The use of different starter cultures showed that Bacillus spp., moulds and some yeasts were capable to release or form the bioactive component during fermentation, thus the bioactivity was not specific for one microbial species.
After heating, defatting and protease treatment of the bioactive tempe extracts, they remained bioactive. On the contrary, after treatment with polysaccharide degrading enzyme mixtures the bioactivity was lost. This suggests that the bioactive component contains carbohydrates, and explains the interaction between ETEC and tempe extracts, which could indeed be established by carbohydrates of the tempe extract. Ultra-filtration revealed the bioactive component to have molecular masses >30 kDa. Further purification yielded an active fraction with an increased carbohydrate content. Monosaccharide analysis showed the importance of arabinose in the bioactive components.
In conclusion, the bioactive component is released or formed during fermentation by enzymatic degradation of legumes. The bioactive component is of carbohydrate nature and contains arabinose, which originates from arabinan or arabinogalactan chains of the pectic cell wall polysaccharides of legumes.
LanguageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Zwietering, Marcel, Promotor
  • Gruppen, Harry, Promotor
  • Nout, Rob, Co-promotor
Award date8 Oct 2010
Place of Publication[S.l.
Publisher
Print ISBNs9789085857136
Publication statusPublished - 2010

Fingerprint

enterotoxigenic Escherichia coli
diarrhea
beans
bacteria
legumes
fermentation
extracts
arabinose
carbohydrates
adhesion
polysaccharides
defatting
arabinogalactans
fermented foods
Bacillus (bacteria)
starter cultures
monosaccharides
ultrafiltration
Bacillus cereus
carbohydrate content

Keywords

  • tempeh
  • soyabeans
  • diarrhoea
  • enzyme activity
  • arabinose
  • fermentation
  • bioactive compounds

Cite this

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title = "Bioactive components of fermented soya beans effective against diarrhoea-associated bacteria",
abstract = "Tempe is a fermented food, obtained by fungal fermentation of soya beans. During the processing specific flavour, texture and nutritional properties are achieved. Previous research has indicated that tempe reduced the incidence and severity of diarrhoea. In this thesis the bioactive effects of tempe on diarrhoea-associated bacteria are described. Tempe appeared to be antibacterial against Bacillus cereus cells and spores, but not against enterotoxigenic Escherichia coli (ETEC). Nevertheless, tempe was found to inhibit the adhesion of ETEC to intestinal epithelial cells. Experiments showed that the inhibition of adhesion was caused by an interaction between ETEC and tempe extracts. A range of ETEC strains was shown to be sensitive for the anti-adhesive component, making the bioactivity of broader interest for applications in feed matrices. Furthermore, several substrates (legumes and cereals) were fermented and all fermented legumes tested were equally bioactive as the fermented soya beans, whereas the fermented cereals were not active. The use of different starter cultures showed that Bacillus spp., moulds and some yeasts were capable to release or form the bioactive component during fermentation, thus the bioactivity was not specific for one microbial species. After heating, defatting and protease treatment of the bioactive tempe extracts, they remained bioactive. On the contrary, after treatment with polysaccharide degrading enzyme mixtures the bioactivity was lost. This suggests that the bioactive component contains carbohydrates, and explains the interaction between ETEC and tempe extracts, which could indeed be established by carbohydrates of the tempe extract. Ultra-filtration revealed the bioactive component to have molecular masses >30 kDa. Further purification yielded an active fraction with an increased carbohydrate content. Monosaccharide analysis showed the importance of arabinose in the bioactive components. In conclusion, the bioactive component is released or formed during fermentation by enzymatic degradation of legumes. The bioactive component is of carbohydrate nature and contains arabinose, which originates from arabinan or arabinogalactan chains of the pectic cell wall polysaccharides of legumes.",
keywords = "temp{\'e}, sojabonen, diarree, enzymactiviteit, arabinose, fermentatie, bioactieve verbindingen, tempeh, soyabeans, diarrhoea, enzyme activity, arabinose, fermentation, bioactive compounds",
author = "{Roubos-van den Hil}, P.J.",
note = "WU thesis 4896",
year = "2010",
language = "English",
isbn = "9789085857136",
publisher = "S.n.",
school = "Wageningen University",

}

Roubos-van den Hil, PJ 2010, 'Bioactive components of fermented soya beans effective against diarrhoea-associated bacteria', Doctor of Philosophy, Wageningen University, [S.l..

Bioactive components of fermented soya beans effective against diarrhoea-associated bacteria. / Roubos-van den Hil, P.J.

[S.l. : S.n., 2010. 152 p.

Research output: Thesisinternal PhD, WUAcademic

TY - THES

T1 - Bioactive components of fermented soya beans effective against diarrhoea-associated bacteria

AU - Roubos-van den Hil, P.J.

N1 - WU thesis 4896

PY - 2010

Y1 - 2010

N2 - Tempe is a fermented food, obtained by fungal fermentation of soya beans. During the processing specific flavour, texture and nutritional properties are achieved. Previous research has indicated that tempe reduced the incidence and severity of diarrhoea. In this thesis the bioactive effects of tempe on diarrhoea-associated bacteria are described. Tempe appeared to be antibacterial against Bacillus cereus cells and spores, but not against enterotoxigenic Escherichia coli (ETEC). Nevertheless, tempe was found to inhibit the adhesion of ETEC to intestinal epithelial cells. Experiments showed that the inhibition of adhesion was caused by an interaction between ETEC and tempe extracts. A range of ETEC strains was shown to be sensitive for the anti-adhesive component, making the bioactivity of broader interest for applications in feed matrices. Furthermore, several substrates (legumes and cereals) were fermented and all fermented legumes tested were equally bioactive as the fermented soya beans, whereas the fermented cereals were not active. The use of different starter cultures showed that Bacillus spp., moulds and some yeasts were capable to release or form the bioactive component during fermentation, thus the bioactivity was not specific for one microbial species. After heating, defatting and protease treatment of the bioactive tempe extracts, they remained bioactive. On the contrary, after treatment with polysaccharide degrading enzyme mixtures the bioactivity was lost. This suggests that the bioactive component contains carbohydrates, and explains the interaction between ETEC and tempe extracts, which could indeed be established by carbohydrates of the tempe extract. Ultra-filtration revealed the bioactive component to have molecular masses >30 kDa. Further purification yielded an active fraction with an increased carbohydrate content. Monosaccharide analysis showed the importance of arabinose in the bioactive components. In conclusion, the bioactive component is released or formed during fermentation by enzymatic degradation of legumes. The bioactive component is of carbohydrate nature and contains arabinose, which originates from arabinan or arabinogalactan chains of the pectic cell wall polysaccharides of legumes.

AB - Tempe is a fermented food, obtained by fungal fermentation of soya beans. During the processing specific flavour, texture and nutritional properties are achieved. Previous research has indicated that tempe reduced the incidence and severity of diarrhoea. In this thesis the bioactive effects of tempe on diarrhoea-associated bacteria are described. Tempe appeared to be antibacterial against Bacillus cereus cells and spores, but not against enterotoxigenic Escherichia coli (ETEC). Nevertheless, tempe was found to inhibit the adhesion of ETEC to intestinal epithelial cells. Experiments showed that the inhibition of adhesion was caused by an interaction between ETEC and tempe extracts. A range of ETEC strains was shown to be sensitive for the anti-adhesive component, making the bioactivity of broader interest for applications in feed matrices. Furthermore, several substrates (legumes and cereals) were fermented and all fermented legumes tested were equally bioactive as the fermented soya beans, whereas the fermented cereals were not active. The use of different starter cultures showed that Bacillus spp., moulds and some yeasts were capable to release or form the bioactive component during fermentation, thus the bioactivity was not specific for one microbial species. After heating, defatting and protease treatment of the bioactive tempe extracts, they remained bioactive. On the contrary, after treatment with polysaccharide degrading enzyme mixtures the bioactivity was lost. This suggests that the bioactive component contains carbohydrates, and explains the interaction between ETEC and tempe extracts, which could indeed be established by carbohydrates of the tempe extract. Ultra-filtration revealed the bioactive component to have molecular masses >30 kDa. Further purification yielded an active fraction with an increased carbohydrate content. Monosaccharide analysis showed the importance of arabinose in the bioactive components. In conclusion, the bioactive component is released or formed during fermentation by enzymatic degradation of legumes. The bioactive component is of carbohydrate nature and contains arabinose, which originates from arabinan or arabinogalactan chains of the pectic cell wall polysaccharides of legumes.

KW - tempé

KW - sojabonen

KW - diarree

KW - enzymactiviteit

KW - arabinose

KW - fermentatie

KW - bioactieve verbindingen

KW - tempeh

KW - soyabeans

KW - diarrhoea

KW - enzyme activity

KW - arabinose

KW - fermentation

KW - bioactive compounds

M3 - internal PhD, WU

SN - 9789085857136

PB - S.n.

CY - [S.l.

ER -