Potential of Microalgae

The aim of this chapter is to present the potential of microalgae and cyanobacteria, which have been less explored and used than other microorganisms like archaea, bacteria or yeasts in the green chemistry sector. These photosynthetic microorganisms have so far been cultivated for high added value applications, mainly for pigments and antioxidants, but a key advantage is their ability to fix CO2 and store it efficiently in the form of polysaccharides and lipids. Today, their global production stands at around 27,000 tons per year, in open raceway ponds, photobioreactors and heterotrophic fermenters with productivities a range of order higher than for terrestrial plants. The production of molecules of interest is generally stimulated by a stress triggered right after a growing phase. Cultivation processes must still progress for reducing the production costs and the associated environmental impact, especially by reducing the energy need for harvesting and for providing a light access to the cells. Other barriers still need to be overcome throughout the chain value so that microalgae can offer a varied and abundant resource for green chemistry.