Open AccessAcetyl‐CoA cleavage pathway in a syntrophic propionate oxidizing bacterium growing on fumarate in the absence of methanogens
Author(s) -
Plugge Caroline M.,
Dijkema Cor,
Stams Alfons J.M.
Publication year - 1993
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1993.tb06297.x
Subject(s) - propionate , fumarate reductase , citric acid cycle , biochemistry , fermentation , bacteria , tricarboxylic acid , chemistry , enzyme , acetate kinase , metabolic pathway , succinate dehydrogenase , biology , escherichia coli , gene , genetics
A syntrophic propionate‐oxidizing bacterium was able to grow in the absence of methanogens by fermentation of fumarate to succinate and CO 2 . The pathway involved in the conversion of fumarate was investigated. During fermentation of unlabelled fumarate cells incorporated [1‐ 13 C]acetate, [2‐ 13 C]acetate and [1,2‐ 13 C]acetate into C2 and C3 of succinate, but not into C1 and C4. This observation, together with the absence of essential enzymes, showed that the citric acid cycle is not used for the oxidation of fumarate to CO 2 . All the enzymes of the acetyl‐CoA cleavage pathway were detected, indicating that this pathway is involved in fumarate oxidation to CO 2 . During growth on propionate this acetyl‐CoA cleavage pathway may have an anaplerotic function.