ISOLATION OF A GLYPHOSATE-METABOLIZING PSEUDOMONAS - DETECTION, PARTIAL-PURIFICATION AND LOCALIZATION OF CARBON-PHOSPHORUS LYASE

A Pseudomonas isolate (GLC11) capable of growth in the presence of up to 125 mM glyphosate [N-phosphonomethyl glycine (PMG)] has been isolat ed. Unlike the previously isolated Pseudomonas PG2982 and other bacter ial strains, isolate GLC11 grows equally well in commercial formulatio n and analytical grade PMG. Utilisation of PMG as a phosphorus source is repressed by inorganic phosphate (Pi) in both isolates. Enzymatic a ctivity responsible for carbon-phosphorus bond cleavage (C-P lyase) wa s detected in cell-free extracts of both isolates and was partially pu rified. Resolution on DE-52 anion exchange chromatography yielded a si ngle peak of C-P lyase activity. The molecular mass of C-P lyase as an alysed by gel permeation chromatography is approximately 200 kDa. The enzyme activity was localised in the periplasmic space of bacteria. Th e specific activity of C-P lyase was different for different phosphona tes when used as substrates.