Palmelloid Formation of <i>Chlamydomonas</i>

Abstract

Abstract Organic acids such as citrate, oxalate, succinate, fumarate, malate, glutamate, aspartate, glycolate and phthalate induce palmelloid formation at neutral pH in liquid cultures of Chlamydomonas , while acetate hardly does it. The palmelloids consist of a minimum of four cells and are embedded in a jelly‐like material. The effective organic acids are generally not only unutilizable as respiratory substrates, but affect also slightly the respiration or photosynthesis and tend to inhibit growth. In a synchronous culture, an addition of citrate at an early stage of a light or dark period has little or no effect on cell growth and multiplication but inhibits the dissociation of divided daughter cells strikingly.