Fractionation and purification of the phycobiliproteins from Spirulina platensis.

C-Phycocyanin and allophycocyanin of Spirulina platensis are fractionated and purified using a non-chromatographic method namely, aqueous two phase extraction for the first time. Optimized process parameters of aqueous two phase extraction (PEG 4000/potassium phosphate of tie line length 18.64% with a phase volume ratio 1.45) resulted in pure C-phycocyanin and allophycocyanin with a purity of 3.23 and 0.74, respectively, in a single extraction. Multiple extractions (two) improved the purity of C-phycocyanin from 3.23 to 4.02. Integration of aqueous two phase extraction with membrane process not only facilitated the separation of phase forming components from the products and also increased the purity of allophycocyanin from 0.74 to 1.5.