LAUSR

Arthrospira maxima is reported to have the highest protein content among different species of Cyanobacteria. In the present work, extraction of C-phycocyanin (C-PC) and allophycocyanin (A-PC) from dry biomass of A. maxima was carried out for the first time using ultrasound-assisted extraction (UAE), enzyme-assisted extraction (EAE), and their combination. The total extractable C-PC and A-PC were estimated to be 47.89 and 39.95 mg g−1 dry biomass, respectively, from serial extraction. UAE resulted in better yield and purity compared with EAE. At standardized conditions of UAE (1:15 solid–liquid ratio, 20% amplitude and 4 min ultrasonication time), the highest yield, purity and extraction efficiency achieved were 44.5 mg g−1d.b, 2.0 and 93% for C-PC and 29.93 mg g−1d.b, 0.89 and 75% for A-PC, respectively. The purity observed is the highest reported in primary extraction to date. Combination of methods did not result in significant improvement with respect to yield and purity. Considering both yield and purity, ultrasound-assisted extraction alone was inferred to be the most suitable method for extraction of phycocyanins from the dry biomass of A. maxima.