Characterization of oxime metabolizing enzymes in a cyanobacterium Phormidium uncinatum, utilizing ethyl acetohydroximate as sole nitrogen source

Ethyl acetohydroximate-adapted phototrophic cultures of Phormidium uncinatum metabolized this oxime via hydrolysis/oxidation and dismutation of resulting hydroxylamine to nitrite and ammonia. Participating enzymes were bound to thylakoid membranes, which were solubilized and purified by conventional techniques using QAE-Sephadex and DEAE-Cellulose columns. Specific activity of bound enzymes increased in the range of 25-75 folds. With partially purified enzymes, apparent Km values of hydrolase and oxidase for oxime and dismutase for hydroxylamine were 180, 15 and 36 mu M respectively.