Microalgae, capable of performing photosynthesis, are important for life on earth; they produce approximately half of the atmospheric oxygen[2] and use simultaneously the greenhouse gas carbon dioxide to grow photoautotrophically. Microalgae, together with bacteria, form the base of the food web and provide energy for all the trophic levels above them. Microalgae biomass is often measured with chlorophyll a concentrations and can provide a useful index of potential production.