Performance intensification of CO2 absorption and microalgae conversion (CAMC) hybrid system via low temperature plasma (LTP) treatment

CO2 absorption and microalgae conversion (CAMC) hybrid system is a promising alternative for simultaneous carbon capture and utilization. It can not only overcome the challenge of high energy consumption solvent thermal regeneration in chemical CO2 absorption, but also enhance the carbon conversion efficiency in biological conversion process. However, the discordance between CO2 absorption and bio-conversion rate has become the key to limiting the development of CAMC system. Therefore, in this study, low temperature plasma (LTP) mutation breeding technology was used to training Chlorella strains by combining undirected mutagenesis and directional screening. Then, the mutagenic microalgae were cultivated and evaluated in CAMC system. It was found that compared with original Chlorella L166, the OD680 of mutant strain L166-M3 in CAMC system increased 7.8%, and the maximum specific growth rate improved 27.5%. The carbon sequestration rate of wild Chlorella L166 increased from 82.9% to 93.7% after mutation treatment, the activity of RubisCO, and the content of NADPH produced by photoreaction increased 37.2% and 17.2%. In addition, lipid production of L166-M3 increased to 6.89 mg/L, which was 15.4% higher than original Chlorella L166. It could be observed that LTP mutation breeding could be used as a potential method for training algae species and improve the overall performance of CAMC system.