Abstract: To obtain a microalgae growing well in the condition of stack gases and to find a good method of fixing greenhouse gases,the ZY-1 strain identified as a species of Chlorella genus was isolated from soil-water mixture samples collected from a paddy field after an enrichment culture using the reproduced stack gases containing15% of CO₂ and 2% of O₂.The results showed that the range of CO₂ concentration for the optimum growth of the ZY-1 strain was 10～15%.The ZY-1 strain had its maximum growth when the CO₂ concentration was 10%.Under a broad range of physically conditions including0.25～0.75 L·min^-1 of air flowing rate,25～30℃ of temperature and pH4～6,the ZY-1 strain had a steady growth.The optimum cultural condition with 0.397% of the CO₂ utilization efficiency was seemed to be 10% of CO₂,25℃ and pH5.0. It is feasible to fix greenhouse gases using the stack gases combined with the ZY-1 strain.

Key words: Microalgae, Greenhouse gas, CO₂, Fixation