Improvement of Thermosynechococcus sp. CL-1 performance on biomass productivity and CO2 fixation via growth factors arrangement

Abstract

The enormous attraction on CO2 biofixation using photosynthetic microorganisms such as cyanobacteria has been risen due to its promising efficiency and valuable by-products production. In this study, an isolated cyanobacterium from hot spring in Taiwan, Thermosynechococcus sp. CL-1 (TCL-1) was evaluated for its growth factors arrangement effect on the biomass productivity and CO2 biofixation. The initial biomass concentration, and nutrient supply level variation influenced TCL-1 biomass productivity and CO2 biofixation rate while the adjusted and controlled pH value gave an insignificant difference on its performance. The initial biomass concentration of 3 g L−1 gave the best result on biomass productivity and CO2 fixation which reached 143.4 mg L−1 h−1 and 224 mg L−1 h−1 respectively. Regarding to the result of this study, controlled pH value by the CO2 supply inside the reactor, produced an insignificant difference in TCL-1 performance compared to those with the uncontrolled pH value. The variation of nutrient supply level was achieved by the variation of macronutrient and micronutrient supply inside the medium. The G-solution contains metals and other micronutrient elements which are necessary for the growth of TCL-1. The combination between 5–folds MF medium as the macronutrient, and 3-folds G-solution as the micronutrient supply, present the best TCL-1 performance on biomass productivity and CO2 fixation rate.