MORPHOLOGICAL-CHANGES IN THE LIFE-CYCLE OF THE GREEN-ALGA HAEMATOCOCCUS-PLUVIALIS

A 2-week model life cycle of the green alga Haematococcus pluvialis wa s constructed, consisting of four cell stages: vegetative cell growth, encystment, maturation, and germination. Each algal cell stage could be distinguished by the ratio of pigments (carotenoid/chlorophyll) and the intracellular protein content. Using the culture system developed , light was shown to be essential for both carotenogenesis and cell di fferentiation (encystment and germination). The results also suggested that H. pluvialis has a novel photosynthesis-dependent system of caro tenogenesis regulation.