The use of microalgae and their derivatives is spreading in many sectors, enhancing the biosynthesis and biorefining functions of microorganisms. The limit today is the cost but there are already markets where this parameter can be compensated by the best characteristics of the algal product, such as high purity (nutraceuticals and functional foods), or by functional uniqueness, such as feed supplements to reduce methane emissions in livestock farming, or finally for the scale on which microalgae famss can be created (CO2 absorption, wastewater purification, industrial substances)