Permeability limits of cell walls in suspension cultures: Biotechnologicaland physiological aspects

The report gives an overview on the permeability of cell walls in plant sus pension cultures for macromolecules of different size. It is stressed that primary walls of suspension culture cells are ultrafilters with interesting technical properties and that cell-wall capsules, obtained from such cultu res, are a suitable packing material and may be applied for the separation of polymers by a new type of chromatography (vesicle chromatography). Sever al advantages of this chromatography and methods for determining the size l imits for cell-wall permeation are described. Biotechnological studies rais ed various physiological questions which refer to the dependence of the pri mary wall structure on cell growth and nutrition: 1. Which cell-wall compon ents are responsible for the permeation limiting pore size of type I cell w alls, typical of most taxa of higher plants, and type II cell walls charact eristic of the Poaceae? 2. Are there characteristic changes in cell-wall pe rmeability within a cultivation cycle? 3. Is the pore size of the cell wall s dependent on carbohydrate or mineral limitations? Recent results regardin g these questions are presented and discussed.