Chromatographic purification of C‐phycocyanin from Spirulina platensis: assessing antioxidant activity and stability

Abstract

AbstractBACKGROUNDThe efficient separation and purification of proteins like C‐phycocyanin (C‐PC) from Spirulina platensis are essential for their commercialization, yet they remain challenging. This study investigated three chromatographic methods for C‐PC purification: weak anion exchange chromatography (DEAE), strong anion exchange chromatography (Q Sepharose), and hydrophobic interaction chromatography (HIC).RESULTSWeak anion exchange chromatography achieved a recovery of 36.80 mg unit (57.08%) with a purity of 3.23, outperforming Q Sepharose (yield: 23.21 mg unit means that 46.33%, purity: 2.76) and HIC (yield: 22.95 mg unit means that 17.57%, purity: 3.02). The purified C‐PC consisted of α and β subunits with molecular masses of 16 kDa and 17 kDa, respectively. Further assessment revealed its antioxidant capacity through a 2,2'‐Azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) assay. The stability of C‐phycocyanin was tested at different pH levels and temperatures. Maximum stability was observed at pH 7, and pH 4 showed the lowest stability. Glutaraldehyde‐treated C‐PC (GC‐PC) demonstrated gradual degradation up to 50 °C, retaining 73.25% after 30 min. Notably, GC‐PC exhibited stability even at higher temperatures, with degradation rates of 57.32% at 70 °C and 50.96% at 80 °C.CONCLUSIONWeak anion exchange chromatography proved superior for C‐PC purification, offering higher yields and purity than Q Sepharose and HIC. The purified C‐PC showed promising antioxidant capacity and stability, particularly GC‐PC, which exhibited resistance to degradation, even at elevated temperatures. These findings underscore the potential of C‐PC as a valuable compound for various applications, with DEAE chromatography being an efficient method for its production and commercialization. © 2024 Society of Chemical Industry.