Environmental stress physiology with reference to mass cultures

When dealing with a photoautotrophic growth system, the biological process that drives growth and productivity is the ability of the cells via their photosynthetic apparatus to capture light and convert it efficiently to chemical energy. This chapter examines the basic principles of algal photosynthesis and growth physiology in order to provide the reader with the necessary background for a more comprehensive understanding of the effect of stress on algal photosynthesis and growth. Particular emphasis has been put on the light acclimation process of outdoor microalgae cultures and on the synergistic effect of light and other environmental stress such as low temperature, salinity, and high oxygen concentrations on algal photosynthesis and productivity. Chlorophyll fluorescence measurement has been suggested as a powerful tool to rapidly monitor the effect of stress on algal photosynthesis and growth. We strongly believe that the future of algal biotechnology highly depends on the ability to better understand its biological limitations and what needs to be overcome in order to significantly improve productivity.