Optimizing inorganic carbon and salinity for enhanced biomass and pigment production in Colaconema formosanum: Implications for sustainable carbon sequestration and stress responses.

[Display omitted] • 30–36 psu and 1.2 g/L of inorganic carbon stimulate growth rates of 18% per day. • Algae alter phycobiliprotein ratio to manage salinity and inorganic carbon stress. • Phycocyanin concentration is significantly affected by salinity. • Two factors interactions don't affect chlorophyll and photosynthetic efficiency. • Below 25 psu, salinity had more significant effect on algae than inorganic carbon. This study investigates a cultivation strategy for the macroalga Colaconema formosanum by determining optimal inorganic carbon concentration and salinity for maximizing biomass and photosynthetic pigment production while also facilitating carbon sequestration. The response surface method was used with a central composite design (CCD-RSM) to determine the optimal conditions. Results showed that adding 1.2 g/L of carbon increased the specific growth rate to 18%–19% per day. The maximum amount of pigment, including phycobiliprotein and chlorophyll, was achieved by adjusting both carbon content and salinity. This strategy enables mass pigment production and offers an eco-friendly approach to carbon sequestration while reducing culture period. This study also sheds light on algal mechanisms against enriched inorganic carbon and salinity content, contributing to an enhanced understanding of these vital processes. [ABSTRACT FROM AUTHOR]