Increased C-phycocyanin extract purity by flocculation of Arthrospira platensis with chitosan

• Published in: Algal research (Amsterdam) 2021-10, Vol.58, p.102393, Article 102393
• Main Authors: Sukhinov, Daniil V., Gorin, Kirill V., Romanov, Alexander O., Gotovtsev, Pavel M., Sergeeva, Yana E.
• Format: Article
• Language: English
• Subjects: Antioxidant activity; Arthrospira platensis; C-phycocyanin; Chitosan; Flocculation; Thermal stability
• ISSN: 2211-9264; 2211-9264
• DOI: 10.1016/j.algal.2021.102393

This paper demonstrates the possibility of harvesting cyanobacteria Arthrospira platensis at various growth phases followed by the extraction of purer C-phycocyanin from the flocculated biomass, by using chitosan as a flocculating agent. It was found that the flocculation efficiency was higher than 90% in 15 min for the chitosan concentrations of 50 and 100 mg/L, regardless of the growth phase. The C-phycocyanin purity (A620/A280) correlates with chitosan concentration and reaches the values of 1.6–1.9 for the chitosan concentrations of 50 and 100 mg/L with the growth phase dependence. C-phycocyanin extracted from the flocculated (by 50 and 100 mg/L of chitosan) biomass also had enhanced thermal stability as clearly demonstrated by an increase in a residual concentration from 55% to 85–91% when compared with the control after incubation at 60 °C for 150 min. Nevertheless, antioxidant activity of C-phycocyanin extracts obtained after flocculation processes was 28–37% less compared with the control samples. Thus, the use of chitosan as a flocculating agent for cyanobacteria A. platensis harvesting reduces the time of biomass collecting, increases extracted C-phycocyanin thermal stability and purity (on average, 1.5 times compared with the control), which makes it possible to use it in the food and cosmetic industries, bypassing a purification stage and stabilizing agents addition. [Display omitted] •Chitosan was successfully applied for Arthrospira platensis flocculation.•Chitosan as a flocculant enhances the C-phycocyanin purity up to 1.60 times.•Chitosan as a flocculant increases C-phycocyanin thermal stability by 30% at 60 °C.•Chitosan had no effect on C-phycocyanin recovery.•Flocculation processes reduced antioxidant activity of C-phycocyanin by 28–37%.