High cell density culture of microalgae in heterotrophic growth

Microalgae are a great source of many highly valuable products such as polyunsaturated fatty acids, astaxanthin and bioactive compounds. Large-scale production of these products, however, has been hindered by an inability to obtain high cell densities and productivities in conventional photoautotrophic systems. High cell density processes suitable for heterotrophic cultures of microalgae may provide an alternative means for the large-scale production of algal products of high value. This paper reviews recent studies on the formation of algal products in various cultivation systems, with emphasis on the use of heterotrophic techniques. The potential employment of heterotrophic high cell density strategies for commercial production is discussed.