Combining glucose and sodium acetate improves the growth of neochloris oleoabundans under mixotrophic conditions

Abstract

Mixotrophic cultivation is a potential approach to produce microalgal biomass that can be used as raw materials for renewable biofuels and animal feed, although using a suitable, cost-effective organic carbon source is crucial. Here, we used a Box–Behnken design with three factors, the glucose and sodium acetate concentrations, and the percentage of Bold’s basal medium (BBM), to evaluate the effects of different carbon sources on biomass productivity and the protein and lipid contents of Neochloris oleoabundans (UTEX#1185). When grow at optimal levels of these factors, 100% BBM plus 7.5 g L−1 each of glucose and sodium acetate, N. oleoabundans yielded 1.75 g L−1 of dry biomass, with 4.88 ± 0.09% N, 24.01 ± 0.29–30.5 ± 0.38% protein, and 34.4% ± 0.81 lipids. A nuclear magnetic resonance spectrum (1H-NMR) of a lipid extract showed that the free fatty acid content was 11.25%. Thus, combining glucose and sodium acetate during the mixotrophic cultivation of N. oleoabundans can yield greater amounts of biomass, proteins, and lipids for biofuel production.