Control of palmelloid formation in the green algaPediastrum

摘要

Pediastrum tetras, normally a non-motile colony of eight cells, aggregates into large masses of up to 1500μin diameter when grown in certain nutrient media. These masses (“palmelloids”) can be prevented from forming or can be dissociated into separate colonies by either high pH or ferric ions. The average particle size is inversely proportional to the concentration of Fe+++between zero and about 300μm. Iron chelators such as EDDHA have no effect. These data are discussed in comparison with the control of palmelloid formation in other g