Microalgae cultivation

Abstract

With the rapid development of the world economy and the increasing population, the gap of energy demand is increasing during the past decades. Microalgae are alternative feedstocks for biofuels production, especially for biodiesels. Microalgae have high photosynthetic efficiency and biomass productivity compared with other terrestrial plants. Microalgae culture is critical part for algal-based biofuel development. At the beginning, working algal strain should be selected. It could be isolated or improved by mutagenesis. Adaptive laboratory evolution is a powerful tool for improving the metabolic phenotype of microalgae. The culture conditions including nutrient, temperature, pH, light quality and light intensity, CO 2 concentration and others should be optimized to support growth and lipid accumulation in microalgae. A suitable magnetic or electric field may also promote the growth of microalgae. In addition, culture mode and operation strategy are also important for obtaining high lipid productivity. Photobioreactor is the core equipment for microalgae culture. Suspension culture is widely conducted in large-scale outdoor cultivation. The structure of a photobioreactor and culture condition should be optimized. Attached culture is also proposed while the supporting materials and culture conditions are essential to improve efficiency of the attached culture. Co-culture is a possible selection and has some advantages while much more studies on pilot scale should be performed. Long-term cultivation needs control microbial contamination in photobioreactor. The microalgae culture is a systematic work from strain selection, optimization of culture conditions and photobioreactor design. It is critical to reduce the production cost of biofuels.