Affordable Access

Xylose, arabinose, and rhamnose fermentation by Bacteroides ruminicola.

Authors
  • Turner, K W
  • Roberton, A M
Type
Published Article
Journal
Applied and environmental microbiology
Publication Date
Jul 01, 1979
Volume
38
Issue
1
Pages
7–12
Identifiers
PMID: 485153
Source
Medline
License
Unknown

Abstract

Metabolism and growth yields of Bacteroides ruminicola grown on d-xylose, l-arabinose, and l-rhamnose were studied. Growth yields were 62, 68, and 35.5 g (dry weight) per mol of carbohydrate fermented after correction for storage polysaccharide. Experiments with [1-(14)C]arabinose indicated that pentose was fermented by a pentose phosphate cycle plus glycolysis, with some indication of a minor phosphoketolase-type pathway. The product ratios from pentose were similar to those previously described for hexose. Rhamnose was fermented mainly to 1,2-propanediol, succinate, and acetate, although the latter was quantitatively less than expected. Estimates of adenosine 5'-triphosphate (ATP) molar growth yields could not be calculated with any certainty, as ATP generation by electron transport-linked phosphorylation cannot yet be assessed. If ATP were generated by substrate-level phosphorylation reactions alone, ATP molar growth yields for xylose, arabinose, and rhamnose would be 30, 28, and 35 g/mol. If calculations are based on an assumption that two ATP are generated by electron transport-linked phosphorylation per succinate, ATP molar growth yields become 15, 14, and 22 g/mol; if the assumption is also made that the pathway of lactaldehyde reduction is coupled to production of one ATP per 1,2-propanediol by electron transport-linked phosphorylation, the ATP molar growth yield for rhamnose fermentation becomes 14 g/mol. No preference can be expressed between these alternatives at present.

Report this publication

Statistics

Seen <100 times