AUTHOR=Rafay Ramis , Uratani Joao M. , Hernandez Hector H. , Rodríguez Jorge 

TITLE=Growth and Nitrate Uptake in Nannochloropsis gaditana and Tetraselmis chuii Cultures Grown in Sequential Batch Reactors

JOURNAL=Frontiers in Marine Science

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2020.00077

DOI=10.3389/fmars.2020.00077

ISSN=2296-7745

ABSTRACT=<p>This study aims to determine the maximum specific biomass growth rates of <italic>Nannochloropsis gaditana</italic> and <italic>Tetraselmis chuii</italic> grown in sequential batch reactors. The maximum specific growth rates of <italic>N. gaditana</italic> and <italic>T. chuii</italic> were found to be 0.23 ± 0.04 gVSS/gVSS⋅d and 0.22 ± 0.05 gVSS/gVSS⋅d respectively. Optical density measured at 550 nm (OD<sub>550</sub>) accurately predict volatile suspended solids (VSS) concentration in <italic>N. gaditana</italic> growth media but not in <italic>T. chuii</italic> growth media. We observed decoupling of nitrate uptake from cell growth for both microalgae as growth continued well beyond the point where concentrations of nitrate in the growth media fell below the detection limit. This nitrate decoupling highlights the challenges in current microalgae growth models as growth was independent of the extracellular dissolved nitrogen in the system.</p>