title: Glycollate inhibition of growth of Pseudomonas aeruginosa on lactate medium.
abstract: Glycollate inhibited growth of Pseudomonas aeruginosa in media containing either pyruvate or lactate as carbon sources. Glycollamide, but not glyoxylate, showed similar effects. Spontaneous mutants (L/G strains) were isolated that were able to grow on lactate medium in the presence of glycollate: their growth in pyruvate medium was still inhibited by glycollate. Synthesis of membrane-bound NAD+-independent D(-)- and L(+)-lactate dehydrogenase (iLDHs) was inducible by D- or L-lactate in the parent strain but was constitutive in the L/G strains. Glycollate inhibited induction of the synthesis of iLDHs in the parent strain growing in succinate medium but had no effect under the same conditions on strain L/G1. Glycollate was a competitive inhibitor of L(+)-iLDH (Ki = 11 mM). No differences were found in the kinetic properties of L(+)-iLDH in cell-free extracts from strain L/G1 and the parent organism. Glycollate appears to inhibit growth on lactate medium predominantly through prevention of lactate induction of iLDH synthesis.
mesh_terms: D004790:Enzyme Induction; D006016:Glycolates / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D007773:Lactates / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development*
chemical_list: D006016:Glycolates; D007773:Lactates; D007770:L-Lactate Dehydrogenase