Open AccessOxalate metabolism by the acetogenic bacterium Moorella thermoacetica
Author(s) -
Daniel Steven L,
Pilsl Christine,
Drake Harold L
Publication year - 2004
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 - 10.1016/s0378-1097(03)00924-8
Subject(s) - oxalate , formate , chemistry , metabolism , biochemistry , catalysis , inorganic chemistry
Whole‐cell and cell‐extract experiments were performed to study the mechanism of oxalate metabolism in the acetogenic bacterium Moorella thermoacetica . In short‐term, whole‐cell assays, oxalate consumption was low unless cell suspensions were supplemented with CO 2 , KNO 3 , or Na 2 S 2 O 3 . Cell extracts catalyzed the oxalate‐dependent reduction of benzyl viologen. Oxalate consumption occurred concomitant to benzyl viologen reduction; when benzyl viologen was omitted, oxalate was not appreciably consumed. Based on benzyl viologen reduction, specific activities of extracts averaged 0.6 μmol oxalate oxidized min −1 mg protein −1 . Extracts also catalyzed the formate‐dependent reduction of NADP + ; however, oxalate‐dependent reduction of NADP + was negligible. Oxalate‐ or formate‐dependent reduction of NAD + was not observed. Addition of coenzyme A (CoA), acetyl‐CoA, or succinyl‐CoA to the assay had a minimal effect on the oxalate‐dependent reduction of benzyl viologen. These results suggest that oxalate metabolism by M. thermoacetica requires a utilizable electron acceptor and that CoA‐level intermediates are not involved.