PRELIMINARY ENZYMATIC EVENTS IN ASPARAGINE-DEPENDENT DENITRIFICATION BY PSEUDOMONAS PERFECTOMARINUS.

Best, Audrey N. (University of Georgia, Athens), and W. J. Payne. Preliminary enzymatic events in asparagine-dependent denitrification by Pseudomonas perfectomarinus. J. Bacteriol. 89:1051-1054. 1965.-The initial events leading to denitrification by Pseudomonas perfectomarinus grown anaerobically in the presence of NO(3) (-) were investigated. Conversion of asparagine to malic acid was demonstrated. The nicotinamide adenine dinucleotide phosphate-linked malic acid dehydrogenase in this bacterium was shown to have a dependence for a divalent cation. A transhydrogenase was demonstrated. Oxaloacetic acid, a likely intermediate in conversion of malic to pyruvic acid, was rapidly decarboxylated by enzymes in cell-free extracts. We were not able to show reversible formation of malic acid with oxaloacetic acid and reduced nicotinamide adenine dinucleotide phosphate, nor of oxaloacetic acid with pyruvic acid and CO(2).