Kinetics of mineral nutrient uptake by Saponaria officinalis L. suspensioncell cultures in different media

The uptake of mineral nutrients from two media with different mineral compo sition, a classical MSA medium and a modified MH2 medium, by Saponaria offi cinalis (soapwort) cells was studied over a growth cycle of 14 days, by con tinuous measurement of mineral consumption without opening the culture flas ks. The mineral composition of the MH2 medium was found to be better suited to S, officinalis cells. Culture on MSA medium showed that copper is proba bly a factor limiting growth, that phosphate is rapidly exhausted from this medium, that its strong ammonium concentration is antagonistic to the abso rption of potassium and, lastly, that sodium and chlorine may be considered as non-essential elements.