Catabolism of L-Lysine by Pseudomonas aeruginosa

Abstract

SUMMARYPseudomonas aeruginosa PACI grows poorly on L-lysine as sole source of carbon but mutant derivatives which grow rapidly were readily isolated. Studies with one such mutant, P. aeruginosa ~~~5 8 6 , supported the existence of a route for L-lysine catabolism which differs from those reported previously in other species of Pseudomonas. The postulated route, the cadaverine or decarboxylase pathway, is initiated by the decarboxylation of L-lysine and involves the following steps: L-lysine -+ cadaverine -+ I -piperideine -+ 5-aminovalerate + glutarate semialdehyde -+ glutarate. Evidence for this pathway is based on the characterization of the pathway reactions and the induction of the corresponding enzymes by growth on Llysine. The first three enzymes were also induced by growth on cadaverine and to a lesser extent by 5-aminovalerate. No evidence was obtained for the presence of pathways involving L-lysine 2-monooxygenase or L-pipecolate dehydrogenase, but another potential route for L-lysine catabolism initiated by L-lysine 6-aminotransferase was detected. Studies with mutants unable to grow on L-lysine supported the existence of more than one catabolic pathway for L-lysine in this organism and indicated that all routes converge on a pathway for glutarate catabolism which generates acetyl-CoA. Pipecolate catabolism also appeared to converge on the glutarate pathway in P. aeruginosa. The results suggested that the growth rate of the parental strain is limited by the rate of transport and/or decarboxylation of L-lysine. The cadaverine pathway was present, but not so highly induced, in the parental strain P. aeruginosa PACI . Pseudomonas JEuorescens contained enzymes of both the cadaverine (decarboxylase) and oxygenase pathways, strains of P. putida (biotypes A and B) contained enzymes of the oxygenase pathway but not the decarboxylase pathway and P. multivorans appeared deficient in both. All these species possessed L-lysine aminotransferase activity.

Occurrence of a novel yeast enzyme, l-Lysine -dehydrogenase, which catalyses the first step of lysine catabolism in Candida albicans

“…This compound is probably converted to a-aminoadipate, 2-oxoadipate and glutarate via a pathway similar to that of Pseudornonus aeruginosa (Fothergill & Guest, 1977). The high derepression of the L-lysine edehydrogenase activity from yeast cells grown in lysine-containing medium indicates that the enzyme plays an important role in the catabolism of lysine in C. albicans.…”

Isolation and Properties of Pyruvate Dehydrogenase Complex Mutants of Pseudomonas aeruginosa PAO

“…Nutrient yeast broth (NYB) and nutrient agar were those of Stanisich & Holloway (1972). The minimal salts medium contained (1-l, pH 7.2): KzHP04, 12.5 g; KH2P04, 3.8 g; (NH4)$0,, 1.0 g; 5 ml of a trace elements solution (Fothergill & Guest, 1977). The carbon source, generally potassium lactate, was added as a sterile solution to the sterilized basal medium at a final concentration of 20 mM unless stated otherwise.…”

Molecular characterization of lysR-lysXE, gcdR-gcdHG and amaR-amaAB operons for lysine export and catabolism: a comprehensive lysine catabolic network in Pseudomonas aeruginosa PAO1

“…Both monooxygenase and decarboxylase pathways converge at 5-aminovalerate, which is then converted to glutarate by a pair of transaminase and semialdehyde dehydrogenase encoded by the gabDT operon (Chou et al, 2013;Revelles et al, 2004). Glutarate is proposed to produce acetyl-CoA that can enter the Krebs cycle (Numa et al, 1964), and glutaryl-CoA dehydrogenase enzyme (an enzyme in glutarate catabolism) activity has been reported in crude extracts of P. aeruginosa (Fothergill & Guest, 1977). However, none of the genes for glutarate catabolism and its regulation have been characterized in Pseudomonas.…”

“…P. aeruginosa does not possess the lysine racemase; however, L-Lys catabolism can potentially be connected to the D-Lys pathway via an arginine-pyruvate transaminase AruH (Chou et al, 2010;Yang & Lu, 2007a). One early report suggested the presence of another route through L-lysine 6-amino transferase to make L-pipecolate, which again could possibly convert into glutarate (Fothergill & Guest, 1977). In P. aeruginosa, the alpha amino group of D-Lys can be deaminated by the FAD-dependent D-amino acid dehydrogenase DauA (Li & Lu, 2009a).…”