Composition deChlorella pyrenoidosa, structure des cellules et de leurs lamelles chloroplastiques, en fonction de la carence en azote et de la leveacute;e de carence

摘要

Autospores ofChlorella(produced in synchronized culture) become hypertrophied cells which have lost their capacity for cell division, when deprived of nitrogen during alternating light and dark periods.Biochemical analyses and electron microscopic studies (freeze-etching method) reveal an inhibition of protein and pigment syntheses and some chlorophyll degradation, while lipids and carbohydrates accumulate. The thylakoids appear to be somewhat degraded and their number per chloroplast is decreased.When nitrogen is supplied during the light period, a synthesis of proteins and pigments, and an increase in the thylakoids number are noted, while, simultaneously, the lipid and carbohydrate contents are diminished; this is followed by a re-establishment of cell division.Electron micrographs reveal a development of lamellar particles. According to their sizes and distributions, we can distinguish three kinds of superimposed or juxtaposed populations within the thylakoids lamella.The possible spatial arrangement of these particles is discussed.