Cyanobacteria Mediated CO2 Segregation: A Promising Alternative Method for Sustainable Bioremediation and Biomass Production

Aims: The purpose of this study was to examine the CO2 absorbent (NaOH) affected Spirulina sp. medium culture to verify growth rate, CO2 fixation ability and biomass production from S. platensis using the Zarrouk medium.

Methodology: Cyanobacterium Spirulina sp. was cultured with Zarrouk’s medium at 30±2°C, pH 9 which was obtained from the Applied Botany Section of BCSIR. Besides, to prevent precipitation, the medium without the carbon source was autoclaved for 30 min at 121°C and then the carbon source and NaOH were added. Furthermore, every 6-day intervals, the biomass c content, pH, and alkalinity were measured. The samples were obtained for the same analyses when the biomass concentration reached the blend concentration (0.5 g L-1).

Results: The first concentration was used 0.5 g/L. 47g/L (1.64 mmol/L) of absorbent. The mean increase of 2.45% for biomass generated by the assay using control (2.09 ± 0.11 g) when compared to the NaOH (2.04 ± 0.25 g) was due to the larger number of growth cycles. Besides, a larger number of growth cycles 35.4% for CO2 fixation rate increase compared to the control. The final protein (28.2 ± 4.5 % ww-1) and carbohydrate (19 ± 2.5 % ww-1) content in the biomass cultivated using NaOH was lower than normally found in the control assay (43.4 ± 2.9 % ww-1) and (11.5 ±1.2 % ww-1).

Conclusion: Recent advances in CO2 fixation and biomass production utilizing microalgae were compiled and analyzed, with an emphasis on how adding the CO2 absorbent affected the growth kinetics and biomass composition of Spirulina sp. When compared to the chemical absorbent assay, the control assay's high growth and CO2-fixation rates provide several advantages.