Bastos, Carolina R. V.Maia, Inês BeatrizPereira, HugoNavalho, JoãoVarela, João2022-04-222022-04-222022-04-14Biology 11 (4): 594 (2022)2079-7737http://hdl.handle.net/10400.1/17774S. costatum and C. calcitrans are two cosmopolitan high-value centric diatoms, with a rich nutritional profile. The following work optimised the culture medium of <i>S. costatum</i> and <i>C. calcitrans</i> cultures, respectively, in a stepwise process as follows: 2.4 mM and 1.2 mM of silicate, 4 mM of nitrate, 100 µM of phosphate, 20 and 80 µM iron, and 0.5 mL L⁻¹ of micronutrients. The results that were obtained revealed an increase in biomass productivity with a 1.8- and 3.2-fold increase in biomass that was produced by <i>S. costatum</i> and <i>C. calcitrans</i>, respectively. The biochemical profile showed an increase in high-value PUFAs such as 2.6-fold and 2.3-fold increase in EPA for <i>S. costatum</i> and <i>C. calcitrans</i>, respectively, whilst a 2.6-fold increase in DHA was detected in <i>S. costatum</i> cultures. The present work provides the basic tools for the industrial cultivation of <i>S. costatum</i> and <i>C. calcitrans</i> with enhanced productivity as well as improved biomass quality, two factors which are highly relevant for a more effective application of these diatoms to aquaculture and nutraceutical production.engBiomass growthSilicaNitratePhosphorusIronMicronutrientsSkeletonema costatumChaetoceros calcitransjournal article2022-04-2110.3390/biology11040594