Reductive, coenzyme A-mediated pathway for 3-chlorobenzoate degradation in the phototrophic bacterium Rhodopseudomonas palustris.
We isolated a strain of Rhodopseudomonas palustris (RCB100) by selective enrichment in light on 3-chlorobenzoate to investigate the steps that it uses to accomplish anaerobic dechlorination. Analyses of metabolite pools as well as enzyme assays suggest that R. palustris grows on 3-chlorobenzoate by (i) converting it to 3-chlorobenzoyl coenzyme A (3-chlorobenzoyl-CoA), (ii) reductively dehalogenating 3-chlorobenzoyl-CoA to benzoyl-CoA, and (iii) degrading benzoyl-CoA to acetyl-CoA and carbon dioxide. R. palustris uses 3-chlorobenzoate only as a carbon source and thus incorporates the acetyl-CoA that is produced into cell material. The reductive dechlorination route used by R. palustris for 3-chlorobenzoate degradation differs from those previously described in that a CoA thioester, rather than an unmodified aromatic acid, is the substrate for complete dehalogenation.
Department of Microbiology, University of Iowa, Iowa City, Iowa 52242, USA.
P G
PG
Egland
J
J
Gibson
C S
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Harwood
D001673:Biodegradation, Environmental; D002712:Chlorides / Q000378:metabolism; D002723:Chlorobenzoates / Q000378:metabolism*; D003065:Coenzyme A / Q000378:metabolism*; D010084:Oxidation-Reduction; D012241:Rhodopseudomonas / Q000254:growth & development / Q000378:metabolism*
D002712:Chlorides; D002723:Chlorobenzoates; C036427:3-chlorobenzoic acid; D003065:Coenzyme A