Mechanistic insights into the structure-dependant and strain-specific utilization of wheat arabinoxylan by Bifidobacterium longum

Ang Xin Song, Long Qing Li, Jun Yi Yin, Jia Chi Chiou (Corresponding Author), Jian Yong Wu (Corresponding Author)

Research output: Journal article publicationJournal articleAcademic researchpeer-review

1 Citation (Scopus)


Arabinoxylan (AX), an important dietary fiber from cereal grains, is mainly metabolised in the large intestine by gut bacteria, especially bifidobacteria. This study investigated the uptake and metabolism of wheat AX by a Bifidobacterium longum strain that could grow well with AX as the sole carbon source. The bacterial growth rate showed a significant correlation to the molecular weight (MW) of AX and its acid hydrolysates. Assessment of the key AX degrading enzymes suggested that the uptake and consumption of AX involved extracellular cleavage of xylan backbone and intracellular degradation of both the backbone and the arabinose substitution. The preference for native or partially hydrolysed AX with single substitutions and a sufficiently high MW suggested the structure-dependant uptake by the bacterial cells. Genetic analysis of B. longum showed the lack of β-xylosidase, suggesting the existence of unknown enzymes or dual/multiple-specific enzymes for hydrolysis of the non-reducing end of xylan backbone.

Original languageEnglish
Article number116886
JournalCarbohydrate Polymers
Publication statusPublished - 1 Dec 2020


  • Arabinoxylan
  • Bifidobacteria
  • Degradation mechanism
  • Genomic analysis
  • Molecular weight
  • Strain-specific
  • Structure-dependence

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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