Enhancing phycocyanin yield from Spirulina sp. under salt stress using various extraction methods

Phycocyanin, a blue-coloured pigment, predominantly found and derived from Spirulina sp., has gained researchers' interest due to its vibrant hues and other attractive properties like antioxidant and anti-microbial. However, the lack of reliable and sustainable phycocyanin extraction strategies without compromising the quality has hindered the scaling up of its production processes for commercial purposes. Here in this study, phycocyanin was extracted from wet and dry biomass Spirulina sp., using three different physical cell disruption methods (ultrasonication, homogenization, and freeze-thaw cycles) combined with two different buffers (phosphate buffer and acetate buffer) and water (as control). The result showed that the freeze-thaw method combined with acetate buffer produced the highest yield (25.013 +/- 2.572 mg/100 mg) with a purity ratio of 0.806 +/- 0.079. Furthermore, when subjected to 30% (w/v) salt stress, 1.9 times higher phycocyanin yield with a purity ratio of 1.402 +/- 0.609 was achieved using the previously optimized extraction method.