Abstract
Cells of a strain of Staphylococcus lactis were disrupted by lysozyme treatment and fractionated by differential centrifugation. Proteinase and reduced nicotinamide adenine dinucleotide oxidase were found in the membrane fraction; peptidase and catalase were found in the cytoplasm. Similar results were obtained when cells were broken by sonic oscillation. Proteinase of this organism is considered to be a surface-bound enzyme.