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

• Published in: Scientific reports Vol. 8; no. 1; p. 5112
• Main Authors: Pereira, Hugo, Páramo, Jaime, Silva, Joana, Marques, Ana, Barros, Ana, Maurício, Dinis, Santos, Tamára, Schulze, Peter, Barros, Raúl, Gouveia, Luísa, Barreira, Luísa, Varela, João
• Format: Journal Article
• Language: English
• Published: England 23.03.2018
• ISSN: 2045-2322

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.