[Lipase localization in Serratia marcescens cells]

The localization of lipase was studied in the cells of Serratia marcescens 345. When the cells were treated with sodium cholate, the enzyme bound to the cellular structures was released in the solution. The supernatant obtained after the cells were treated with sodium cholate contained no glucose-6-phosphate dehydrogenase, a well known endocellular enzyme; therefore, the cytoplasmic membrane was not damaged by the treatment. Ultrathin sections of the intact cells and the cells treated with sodium cholate were examined using electron microscopy, and no disorders were detected in the cytoplasmic and outer membranes. It appears therefore that the lipase of S. marcescens 345 is located mainly on the exterior surface of the outer membrane.