Work

Scalable two-stage recovery of C-phycocyanin from Synechocystis salina via tangential ultrafiltration for sustainable textile dyeing

Year: 2026

Type: article

Abstract: C-phycocyanin (C-PC) is a high-value phycobiliprotein extensively used as a natural blue colorant, whose commercial deployment is primarily constrained by downstream purity, stability, and scalability. In this work, a simple, robust, and scalable two-stage process is developed for the recovery of C-PC from Synechocystis salina, combining mild clarification by osmotic shock with tangential-flow ultrafiltration. Phosphate-buffer extraction (0.1 M, pH 7.0) enabled the recovery of 85% of the intracellular C-PC, albeit with low initial purity (A₆₁₅/A₂₈₀ < 0.38). Subsequent ultrafiltration using membranes with molecular weight cut-offs (MWCO) of 10, 50, and 100 kDa allowed simultaneous concentration and purification. The 100 kDa membrane showed the best overall performance, achieving a purity ratio of 1.09, C-PC recovery of 92%, a global yield of 78.1%, and a final concentration of 1.01 mg·mL⁻¹ (14-fold concentration), while maintaining stable permeate flux and low filtration resistance, indicative of favourable scale-up potential. To overcome the intrinsic instability of C-PC, the effect of food-grade stabilizing additives was assessed, extending shelf life at 25 °C from 77 days (no additive) to 127 and 208 days with benzoic and citric acid, respectively. Finally, the purified and stabilized C-PC extracts were successfully applied as natural dyes on different textile materials using conventional mordants, yielding homogeneous coloration with acceptable colour stability. Overall, this integrated clarification–ultrafiltration and stabilization strategy provides an industrially viable route for producing commercial-grade C-PC with enhanced shelf life, enabling its use in food formulations and sustainable textile dyeing.

Source: Algal Research

DOI: 10.1016/j.algal.2026.104683