Bifidogenic effects of Cordyceps sinensis fungal exopolysaccharide and konjac glucomannan after ultrasound and acid degradation

Ang Xin Song, Yu Heng Mao, Ka Chai Siu, Jianyong Wu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

26 Citations (Scopus)


The bifidogenic effects of exopolysaccharide (EPS) of a medicinal fungus (Cordyceps sinensis) and a well-known food polysaccharide konjac glucomannan (KGM) with different molecular weight (MW) ranges were evaluated through in vitro experiments in liquid cultures of Bifidobacteria. Native EPS and KGM were partially degraded with power ultrasound (US) to improve the water solubility, and further hydrolysed with trifluoroacetic acid to much lower MW. The acid-hydrolysed fractions (EPS-AH and KGM-AH) supported the growth of all five tested bifidobacterial species, while the US-degraded high MW fractions, EPS-US and KGM-US, could only slightly support the growth of some species. All EPS fractions increased the acetic acid production of most bifidobacterial species. Most remarkably, the high MW EPS-US, EPS-AH and KGM-US fractions significantly enhanced the cell viability with much higher colony forming unit (CFU) counts, suggesting a protective effect of these high MW polysaccharides for the bacterial survival. The results have shown that MW was a significant factor on the bifidogenic properties of partially degraded EPS and KGM.

Original languageEnglish
Pages (from-to)587-594
Number of pages8
JournalInternational Journal of Biological Macromolecules
Publication statusPublished - 1 May 2018


  • Bifidobacteria
  • Molecular weight
  • Partial degradation
  • Polysaccharide
  • Prebiotic

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • Molecular Biology

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