Nannochloris sp. JB17 as a Potential Microalga for Carbon Capture and Utilization Bio-Systems: Growth and Biochemical Composition Under High Bicarbonate Concentrations in Fresh and Sea Water.

Markou, Giorgos; Kougia, Eleni; Arapoglou, Dimitris

Nannochloris sp. JB17 has been identified as an interesting microalgal species that can tolerate high salinity and high bicarbonate concentrations. In this study, Nannochloris sp. JB17 was long-term adapted to increased bicarbonate concentrations (10–60 g NaHCO3 per L) in fresh or sea-water-based growing media. This study aimed to evaluate its growth performance and biochemical composition under different cultivation conditions. The highest biomass production (1.24–1.3 g/L) achieved in the study was obtained in fresh water media supplemented with 40 g/L and 60 g/L NaHCO3, respectively. Total protein content fluctuated at similar levels among the different treatments (32.4–38.5%), displaying good essential amino acids indices of 0.85–1.02, but with low in vitro protein digestibility (15–20%) rates. Total lipids did not show any significant alteration among the different NaHCO3 concentrations in both fresh and sea water (12.6–13.3%) but at increased sodium strength, a significant increase in unsaturated lipids and in particular a-linolenic acid (C18:3) and linoleic acid (C18:2) was observed. Carbohydrate content also ranged at very similar levels among the cultures (26–30.9%). The main fraction of carbohydrates was in the type of neutral sugars ranging from around 72% to 80% (of total carbohydrates), while uronic acids were in negligible amounts. Moreover, Nannochloris sp. showed that it contained around 8–9% sulfated polysaccharides. Since the microalgae display good growth patterns at high bicarbonate concentrations, they could be a potential species for microalgal-based carbon capture and utilization systems.

CARBON sequestration; ESSENTIAL amino acids; SEAWATER; FRESH water; BIOMASS production

Bioengineering (Basel), 2024, Vol 11, Issue 12, p1301

2306-5354

Academic Journal

10.3390/bioengineering11121301