1P-231: Optimization of a culture medium for Sulfurovum lithotropicum 42BKT T to achieve continuous and stable CO 2 fixation

This work suggests Sulfurovum lithotropicum 42BKT T as a tool for CO 2 fixation which is a chemolithoautotrophic bacterium. It uses thiosulfate as an electron donor and nitrate as an electron acceptor. Main purpose of this work is optimization of a medium for stable biological conversion of CO 2 to biomasses by Sulfurovum lithotropicum 42BKT T . The most important factor in CO 2 fixation by Sulfurovum lithotropicum 42BKT T is culturing cell density highly. One of the limitation in making a high cell density culture medium is ionic strength. When a high salt concentration medium was used to culture high cell density, growth of the cells had been inhibited. To overcome the limitation by ionic strength, concentration of thiosulfate, nitrate, ammonium and chloride ions were varied to increase the cell density without deviating from the suitable region of medium ionic strength. Then, we succeeded in achieving approximately 10 times increase in the cell density.