Effective and low-cost method to obtain purified C-phycocyanins from Arthrospira platensis

Purification of phycocyanin extracts from Arthrospira platensis was evaluated by saline precipitation ((NH4)2SO4, 20-80% saturation) and affinity purification with activated carbon (10-120, g<middle dot>L-1) and chitosan (1-30, g<middle dot>L-1). Moreover, different combinations of these techniques, along with membrane filtration (polyvinylidene fluoride, 0.45 mu m), were explored. For saline precipitation, greatest purity values (1.5) and phycocyanin content (50 mg g-1) in the precipitate were achieved with 50% saturation (NH4)2SO4. Regarding affinity purification, the highest purity (1.71) was obtained with 65 g<middle dot>L-1 of activated carbon and 1 g<middle dot>L-1 of chitosan. Superior purity results were obtained by affinity purification with activated carbon (120 g<middle dot>L-1) followed by salt precipitation ((NH4)2SO4, 50% saturation) and membrane filtration. This combined strategy led to an increase in purity from 1.16 to 2.52. However, there was a 50% reduction in phycocyanin recovery after the first two steps, with no significant difference observed upon the addition of filtration.