earticle

영어

Extensive utilization of fossil fuels has raised environmental pollution, climate change, and health problems. Under this situations, microalgae could be promising alternative energy source such as biodiesel. Moreover, microalgae have strong advantage points to solve environmental pollution through CO2 fixation and wastewater treatment. Generally, microalgae increase their cell numbers under optimized condition and then accumulate lipid under stress condition. Thus, it will be important issues to increase the lipid productivity and to decrease the cultivation cost1.Based on this background, our research focused on increasing the lipid productivity under extra-cellular oxidative stress by TiO2. Basically, TiO2 could produce oxygen radicals under UV condition. By using this mechanism, we hypothesize that under stress condition for growth, lipid in microalgae could be accumulated highly and rapidly2. Chlorella vulgaris was cultivated under the various concentrations of TiO2 from 0.1 to 5 g/L and UV-A conditions. By extra-cellular oxidative stress, chlorophyll and specific growth rate was decreased. Furthermore, Fatty Acid Methyl Ester (FAME) productivity was also decreased according to increasing the concentrations of TiO2. On the contrary, under the low concentrations of TiO2 (0.1 g/L) and short induction time, FAME contents and productivity was the highest. From these results, we suggest that induction by short time and low concentration of extra-celluar oxidative stress could increase the FAME contents and productivity. This work was supported by the Advanced Biomass R&D Center (ABC) of Global Frontier Project funded by the Ministry of Education, Science and Technology (ABC-2010-0029728)