A simple method for extracting phycocyanin from Arthrospira (Spirulina) platensis by autolysis

Phycocyanin (PC) is a natural blue pigment that has great commercial value in food and pharmaceutical industry. Arthrospira (Spirulina) platensis is a photosynthetic spiral-shaped cyanobacterium containing a rich PC pigment. Autolysis is the enzymatic digestion of cells by the action of its own enzymes. To develop an effective and economical extraction process, an autolysis process was incorporated into the conventional freezing-thawing method. In the present study, 91% of maximal extraction yield of PC with 1.194 purity (A₆₂₀/A₂₈₀) was obtained via autolysis after 3 h of incubation at 37 °C without using an extraction salt solution or a successive freezing-thawing process. In addition to temperature, the initial concentration of bicarbonate in growth medium and the concentration of wet biomass are important parameters that influence the extraction yield of PC by autolysis.