CAROTENOGENESIS AND ETHYLENE PRODUCTION IN HAEMATOCOCCUS-PLUVIALIS DURING THE PHOTOPERIOD IN A CLOSED TUBULAR PHOTOBIOREACTOR

The freshwater alga Haematococcus pluvialis from the Chlorophyceae has been cultivated in a tubular closed photobioreactor (2.2 m2 of photos ynthetic area). Changes in carotenoid concentration and ethylene produ ction have been studied over a natural day in August 1991 and July 199 2. The results have shown a circadian rhythm of carotenoid concentrati on and ethylene production. We were able to enhance carotenoid product ion in only a few hours. Experiments in the laboratory in a ''maturing reactor'' under continuous illumination have shown an 2.2 - 3.4-fold increase in carotenoid concentration in 10 h.