Scale-up cultivation of Chlorella ellipsoidea from indoor to outdoor in bubble column bioreactors

The cultivation of Chlorella ellipsoidea in bubble column bioreactors was investigated at different scales under indoor and outdoor conditions. The algal cells were able to quickly adapt to the outdoor conditions and achieved a growth rate of 31.55 mg L−1 day−1. Due to differences in light and temperature, the outdoor culture produced a higher percentage of unsaturated fatty acids compared to the indoor cultures, while the amino acid composition was unaffected. The overall cost of the biomass produced by the 200 L outdoor cultivation (58.70 US$/kg-dry weight) was estimated to be more than 7 times lower than that of the 20 L indoor cultivation (431.39 US$/kg-dry weight). Together these results provide a basis for the cultivation of C. ellipsoidea for the large-scale production of biofuels, high-value nutrients and/or recombinant proteins.