title: Rapid digestion of Staphylococcus aureus by Paramecium: An evaluation of the role of bacterial autolytic enzymes.
abstract: Paramecium fed exclusively with the human pathogenic bacterium Staphylococcus aureus can survive over a period of at least 2 months and is able to use the bacteria as substrate. In this study, Paramecium was fed with S. aureus for 45 min and the process of digestion of these Gram-positive bacteria and their remains was analysed. The degradation starts with very slight damage to the outside of the bacterial cell wall. During digestion, first the cytoplasm and later the membranes are degraded. The cell wall material is gradually broken down at the same time. After 45 min of phagocytosis, defecation competent digestive vacuoles (DVs) are present. There is no difference in the digestive process using bacterial cells from the logarithmic or stationary phase of growth. Cells with abnormally thick cell walls induced by treatment with erythromycin were digested similarly. By using thermally inactivated S. aureus cells, we can exclude the possibility that bacterial autolysines are responsible for the rapid destruction and degradation of the procaryotic cell wall. The Paramecium cells needed longer to digest the coagulated cytoplasm of heat-treated cells.
authors.affiliation: Division of Protozoology, Institute of Zoology, Free University of Berlin, Berlin (West).
authors.forename: I
authors.initials: I
authors.lastname: Mehlis
authors.forename: K
authors.initials: K
authors.lastname: Hausmann
authors.forename: J
authors.initials: J
authors.lastname: Wecke