Abstract: Microalgae are single cell or cell aggregate organisms which can perform photosynthesis and convert CO₂ to microalgae biomass with high efficiency. Microalgae may play a critical role in the reduction of carbon emission. The fundamental mechanism of CO₂ fixation by microalgae through photosynthesis was introduced, and the factors affecting CO₂ fixation efficiency and the utilization of microalgae biomass were reviewed. After a brief economic analysis of CO₂ fixation by microalgae and biomass utilization, it is proposed that microalgae bio-technology might become a new solution for carbon neutrality.

Key words: microalgae, carbon dioxide, bio-energy, protein