Utilization of dicarboxylic acids by Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa ATCC 9027 has been found to lack NAD- or NADP-linked L-malic dehydrogenase. Studies of cell fractions have shown that a nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP) independent, particulate L-malic dehydrogenase catalyzes the oxidation of L-malic acid to oxalacetic acid. The labeling pattern of citric acid obtained from succinate-1,4-14C and succinate-2,3-14C in the wild type and its mutant lacking α-ketoglutarate dehydrogenase have demonstrated involvement of particulate malic dehydrogenase and have excluded any other possibility. The results suggest that the possession of this enzyme rather than the NAD-linked soluble malic dehydrogenase is an advantage to the organism.