PHOTOAUTOTROPHIC CULTIVATION OF THE GREEN-ALGA CHLAMYDOMONAS-REINHARDTII AS A METHOD FOR CARBON-DIOXIDE FIXATION AND ALPHA-LINOLENIC ACID PRODUCTION

Focusing on CO2 fixation and alpha-linolenic acid (ALA) production, ph otoautotrophic cultivation of the green alga Chlamydomonas reinhardtii was investigated by using a culture medium of pH 6.8 under a 5 vol% C O2-enriched atmosphere. The optimum cultivation temperature and light intensity for growth were 25 degrees C and 12 klux, respectively. The cellular ALA content nearly doubled to 11.9 mg/g of dry cells when the concentration of culture medium was doubled. Simulation of chemostat cultivation showed that the rate of CO2 fixation and ALA productivity per unit volume of culture medium could reach 1.01 kg CO2/(m(3) . d) a nd 7.46 g ALA/(m(3) . d), respectively, at a cell concentration of 0.5 7 kg cells/m(3).