Biomaterial Database

Cell wall enzymatic lysis of the yeast form of Pullularia pullulans and wall regeneration by protoplasts. 1975

S Ramos, and I G Acha

During the process of degradation of the cell wall of the yeast form of Pullularia pullulans by the lytic system of micromonospora chalcea samples were withdrawn at different times and observed under phase contrast and electron microscope. The progressive lysis of the walls reveals a fibrillar component inside the apparently amorphous wall. Freeze etched preparations of cells during the formation and regeneration of protoplasts show that the cellular membrane is split and this method allows the smooth external face of the membrane and other internal face covered by particles to be seen. The fact that the smooth face of the membrane is only visible during the preparation or the regeneration of protoplasts and very rarely when intact cells are fractured, suggests a strong adherence between cell wall and this external layer of the membrane. During the regeneration which takes place as in most of the yeasts and moulds, a special study of the extension of the cell wall is made and a possible mechanism for this extension of the regenerated cell wall is proposed.

UI	MeSH Term	Description	Entries
D008847	Micromonospora	A genus of gram-positive bacteria that forms a branched mycelium. It commonly occurs as a saprophytic form in soil and aquatic environments.	Micromonospora echinospora
D011523	Protoplasts	The protoplasm and plasma membrane of plant, fungal, bacterial or archaeon cells without the CELL WALL.	Protoplast
D012038	Regeneration	The physiological renewal, repair, or replacement of tissue.	Endogenous Regeneration,Regeneration, Endogenous,Regenerations
D002473	Cell Wall	The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.	Cell Walls,Wall, Cell,Walls, Cell
D003904	Mitosporic Fungi	A large and heterogenous group of fungi whose common characteristic is the absence of a sexual state. Many of the pathogenic fungi in humans belong to this group.	Deuteromycetes,Deuteromycota,Fungi imperfecti,Fungi, Mitosporic,Hyphomycetes,Deuteromycete,Deuteromycotas,Fungi imperfectus,Fungus, Mitosporic,Hyphomycete,Mitosporic Fungus,imperfectus, Fungi
D005613	Freeze Etching	A replica technique in which cells are frozen to a very low temperature and cracked with a knife blade to expose the interior surfaces of the cells or cell membranes. The cracked cell surfaces are then freeze-dried to expose their constituents. The surfaces are now ready for shadowing to be viewed using an electron microscope. This method differs from freeze-fracturing in that no cryoprotectant is used and, thus, allows for the sublimation of water during the freeze-drying process to etch the surfaces.	Etching, Freeze