In this 2nd-year project, the research team of Fu-Jen University cooperating with Zen-U company applies bio-immobilization and microalgal culture technologies in converting CO2 to valuable microcystins using Microcystis. The results for the project are listed as followings: 1. In term of inorganic carbon sources, the results showed Microcystis.preferred CO2 and possessed the specific growth rate, 0.0192 h-1 ,.when used NaNO3 as a nitrogen source. 2. Using Fractional Factorial Design to analyze nutrient factors, the results showed that NaNO3 is significantly the positive factor affecting the growth of Microcystis. 3. Comparing with different concentrations of NaNO3, the medium IBI adding with 2.0 g/l NaNO3 gave Microcystis with the optimal growth. 4. Microcystins isolated from Microcystis was analyzed by HPLC and found with the peak at 12.23 minutes of the retention time. 5. Microcystis can grow well in the media sparging with 0.03% and 5% of concentrations of CO2, but are inhibited in the media with more than 10% of concentrations of CO2. 6. Parameters of kinetic model for the growth of Microcystis: growth coefficient (Y) 1.1 mg-cell/mg-CO3-2, specific growth rate (m) 0.53 day-1, specific substrate utilization (k) 0.48 mg-CO3-2/mg VSS-day, death coefficient (b) 0.33 day-1, Monod half saturation coefficient (Ks) 0.06 mg-CO3-2/L. 7. In the kinetic model of continuous biofilm photobioreactor for Microcystis the experimented data are statistically matched to modeling data with the standard deviation below 5%, which can be effectively applied to scale-up design. 8. From results of the 200-liter continuous Microcystis-biofilm photobioreactor the better utilization of CO2 and productivity of microcystins were estimated with 7.743 g-CO2/day and 0.4635 mg/day, respectively, while flow rate Q is set on 0.375 L/h in each 50-liter tank and Microcystis biomass reached to 0.92 of OD600 value.

bio-immobilization, bioreactor, carbon dioxide, microcystins, Microcystis