Effect of nutrient supply status on biomass composition of eukaryotic green microalgae

In eukaryotic green microalgae, manipulation of metabolic pathways by altering the culture medium and/or culture conditions represents a powerful tool for physiological control and is usually more practicable than metabolic or genetic engineering. Strategies for nutrient-induced shifts in biomass composition are generally cost-efficient, environmentally friendly, applicable on a large scale and flexible for various industrially attractive microalgae species. In addition, processes, such as nutrient limitation/deprivation, can be readily scheduled and optimised to achieve high levels of productivity for the desired target compound(s). These strategies are currently used in microalgae to achieve overproduction of metabolites such as lipids, polysaccharides and pigments. This paper presents an overview of the species and strain-specific responses of eukaryotic, green microalgal cells that are triggered by variations in selected macronutrient and micronutrient availability. Individual and mutually associated physiological responses to nutrient supply status are described at the molecular level as well as discussed from the perspective of potential biotechnological applications.