[Exolipases of some Pseudomonas species]

The production of exolipase was studied in various Pseudomonas species, most of which did not possess the lipolytic activity in the conditions of the experiment, whereas in some strains this activity was rather high. The highest activity was displayed by the Pseudomonas fluorescens 533 strain and its mutant obtained upon UV irradiation. Lipase biosynthesis depended on the composition of a growth medium, the highest lipolytic activity being found on media with a high content of complex organic substances. No correlation was established between the growth and the lipolytic activity. A lipase preparation was isolated from the Ps. fluorescens 533-5b mutant, partly purified by precipitation with ammonium sulphate and dialysis, and its response to the action of inhibitors and heavy metal ions was studied. The enzyme activity was inhibited by these ions, and stimulated by Mg2+ ions. EDTA was found to be the strongest among all the inhibitors tested.