A novel extraction process of phycobiliproteins with high purity grade from biomass of Arthrospira platensis and Porphyridium cruentum

Phycobiliproteins are water soluble proteins, which are brilliantly colored, highly fluorescentpigments of the photosynthetic light-harvesting antenna complexes of cyanobacteria and somealgae, having many commercial applications in biomedicine, pharmaceutics, cosmetics andfoods.Currently, a simple, reliable, not time consuming, not expensive method to achieve a large-scalesustainable production of high-value phycobiliproteins is a matter of great concern for industry.Here we present a new extraction process [1] developed to extract, with high yield,phycobiliproteins from Arthrospira platensis (Spirulina) and Porphyridium cruentum biomass.The major element of originality and innovation of the process, carried out entirely in aqueoussolution, is the exploitation of a new approach in which 1) the traditional sequence of extractionfollowed by purification is inverted, 2) cell rupture and purification of the product are merged in asingle step.Cell rupture and purification of the product were carried out by ultrasonication in an ammoniumsulphate solution, upstream of the pigment extraction process. The phycobiliproteins wereextracted/recovered subsequently, obtaining a highly concentrated extract (a few mg mL ) andrelatively high purity (P >= 2, usually 2 < P < 4) without downstream purification. Production timeswere reduced, to the advantage of the product quality. In fact, the reduced process time avoidedthe development of the unpleasant smell that often characterizes crude extracts obtained byapplying long lasting extraction procedures, particularly at room temperature.The process has been applied to both fresh and dry biomass, obtaining better results with freshbiomass.