Journal Article

Scale-up and large-scale production of Tetraselmis sp. CTP4 (Chlorophyta) for CO 2 mitigation: from an agar plate to 100-m 3 industrial photobioreactors

Pereira, Hugo, Maurício, Dinis, Gouveia, Luísa, Barreira, Luísa, Schulze, Peter, Páramo, Jaime, Marques, Ana, Silva, Joana, Barros, Ana, Barros, Raúl, Varela, João, Santos, Tamára

2018

Overview

Industrial production of novel microalgal isolates is key to improving the current portfolio of available strains that are able to grow in large-scale production systems for different biotechnological applications, including carbon mitigation. In this context, Tetraselmis sp. CTP4 was successfully scaled up from an agar plate to 35- and 100-m industrial scale tubular photobioreactors (PBR). Growth was performed semi-continuously for 60 days in the autumn-winter season (17 October - 14 December). Optimisation of tubular PBR operations showed that improved productivities were obtained at a culture velocity of 0.65-1.35 m s and a pH set-point for CO injection of 8.0. Highest volumetric (0.08 ± 0.01 g L d ) and areal (20.3 ± 3.2 g m d ) biomass productivities were attained in the 100-m PBR compared to those of the 35-m PBR (0.05 ± 0.02 g L d and 13.5 ± 4.3 g m d , respectively). Lipid contents were similar in both PBRs (9-10% of ash free dry weight). CO sequestration was followed in the 100-m PBR, revealing a mean CO mitigation efficiency of 65% and a biomass to carbon ratio of 1.80. Tetraselmis sp. CTP4 is thus a robust candidate for industrial-scale production with promising biomass productivities and photosynthetic efficiencies up to 3.5% of total solar irradiance.