The oxidative properties of an oxalate-decomposing organism, Pseudomonas OD 1, with particular reference to the synthesis of citrate from glycollate

Abstract

The oxidizing capacities of washed suspensions of Pseudomonas OD1 grown on oxalate, glycollate, lactate, malate and succinate were examined. 2Q2 values are low compared with those for other spp. of Pseudomonas. The oxidizing powers show some response to growth substrate, but there is no clear-cut case of adaptive oxidation of any of the test substrates (mainly C2 acids and tricarboxylic acid cycle intermediates). In general, cells grown on lactate displayed the best oxidizing ability. With cells grown on lactate, 0.001 [image] fluoroacetate strongly inhibits the O2 uptake due to glycine, glycollate or 2-oxoglutarate, but has little effect on that due to acetate or pyruvate. Under the same conditions, the amount of citrate accumulating is increased by glycollate, glycine, pyruvate, succinate, fumarate, malate, oxaloacetate and 2-oxoglutarate, but not by acetate or oxalate. The highest amounts of extra citrate were produced from 2-oxoglutarate, glycollate and glycine, representing about a 50, 30 and 15% conversion, respectively, of substrate C into citrate. Glycollate appears to act as the sole source of C for the extra citrate synthesized in its presence. The glycollate C not converted into citrate appears as CO2. The 2 C atoms of glycollate do not contribute equally to the synthesis of citrate; there is a preferential incorporation of the C-2 atom.