Aerobic metabolism of l-β-lysine in a Pseudomonas. Coenzyme A-dependent acetylation of l-β-lysine

An unidentified Pseudomonas, strain B4, capable of using l-β-lysine as a sole carbon, nitrogen and energy source was isolated from soil. The enzyme system required for the oxidation of this substrate is induced by l-β-lysine and to a lesser degree by 4-aminobutyrate. Extracts of the bacterium contain an enzyme catalyzing a reaction between acetyl-CoA and l-β-lysine to form 6-N-acetyl-l-β-lysine. Lysine, ornithine and other diamino and monoamino acids are not acetylated by this enzyme. The relatively high activity of the acetylating enzyme and the absence of enzymes catalyzing direct oxidation or deamination of l-β-lysine, indicate that acetylation is the first step in β-lysine metabolism in this organism. Acetyl-β-lysine is readily deaminated by extracts in the presence of an α-keto acid to form a second product that is uncharged in acid solution.