TCA METABOLISM BY SOIL MICROORGANISMS

Trichloroacetate (TCA) metabolism by a Pseudomonas sp. isolated from soil requires an exogenous supply of yeast extract for optimal liberation of halide ion. Carbon dioxide evolution and distribution of radioactivity into cellular components from TCA-1-14C and TCA-2-14C are not equal. The nonparallel metabolic pathways for the two carbons in TCA would seem to eliminate a free symmetrical intermediate such as oxalic acid as the first product of TCA decomposition. Serine and two additional metabolites were detected on paper chromatograms. Preliminary enzymic studies demonstrated the necessity of certain cofactors for fragmentation of TCA. Deletion of NADPH or CoA had an inhibitory effect on the capacity of the cell free system to liberate 14CO2, from TCA-1-14C. © 1969, American Chemical Society. All rights reserved.