Modification and improvement of microalgae strains for strengthening CO fixation from coal-fired flue gas in power plants.

Biological CO capture using microalgae is a promising new method for reducing CO emission of coal-fired flue gas. The strain of microalgae used in this process plays a vital role in determining the rate of CO fixation and characteristics of biomass production. High requirements are put forward for algae strains due to high CO concentration and diverse pollutants in flue gas. CO can directly diffuse into the cytoplasm of cells by extra- and intracellular CO osmotic pressure under high CO concentrations. The flue gas pollutants, such as SO, NO and fly ashes, have negative effects on the growth of microalgae. This work reviewed the state-of-the-art advances on microalgae strains used for CO fixation, focusing on the modification and improvement of strains that are used for coal-fired flue gas. Methods such as genetic engineering, random mutagenesis, and adaptive evolution have the potential to facilitate photosynthesis, improve growth rate and reduce CO emission.