Mixotrophic cultivation of Chlorella for biomass production by using pH-stat culture medium:...

Here the study designed a pH-stat culture medium that named as Glucose-Acetate-Phosphorus (GAP) for the mixotrophic cultivation of Chlorella for biomass production. With no addition of pH buffer, the culture pH during mixotrophic growth was effectively maintained steady between 7.5 and 8.5 by balancing the ammonium, acetate and glucose uptakes. Based on the GAP medium supplying with 2 g·L^-1 of total organic carbon, the biomass productions of four Chlorella species were determined as 4.08-4.56 g·L^-1. In contrast to the cultivation using medium Tris-Acetate-Phosphorus (TAP), a algal culture medium that usually regarded as specific for mixotrophy, the cultivation in GAP were about 1.79-1.86 times higher in biomass production and 83.9-88.9% lower in production cost. The developed GAP medium is a promising alternative for the mixotrophic cultivation of microalgae to produce biomass and cellular contents.