Growth and iota-carrageenan from the red seaweed Solieria filiformis (Rhodophyta, Solieriaceae) cultivated in the Ceara State coast, Brazil

The red seaweed Solieria filiformis is a source of nutrients, active biomolecules, and the iota(ι)-carrageenan hydrocolloid. In Brazil, it is found in natural stock; however, the sustainable biomass production of this seaweed species in the sea has not been reported. The S. filiformis cultivation was evaluated at Flecheiras Beach, on the coast of Ceara State in Northeast Brazil, using Long-line with Vertical Rope Structures (LVRS) and Colonized Modules (CM) methods during the rainy and dry seasons. The environmental parameters of the cultivation site, the daily growth rates (DGR) at 30, 45, and 60 days after planting, the biomass density, and the ι-carrageenan extracted were assessed. Local environmental conditions supported seaweed growth in both seasons. However, the highest DGR (6.1%) was recorded 30 days after planting during the dry season using LVRS. The highest seaweed biomass density was 53 kg ws module⁻¹ using CM method. The highest ι-carrageenan yields (48.3% and 53.1%) were obtained from the biomasses produced in the dry season, using LVRS and CM methods, respectively. The mean sulfate content of the ι-carrageenan extracted was 26.8 ± 1.9%, a relevant feature of their physicochemical properties and biological activities.

Graphical Abstract