Optimization,Purification and characterization of Phycocyanin from Spirulina platensis

A method for stably purifying a functional dye, phycocyanin from Spirulina platensis was developed by freezing and thawing method. Among various buffers used for phycocyanin yield efficiency sodium phosphate buffer (pH 7 and 0.1 M) was found to be most suitable for highest yield. During comparison of various buffers, sodium phosphate buffer was found as best buffer with 146 ±0.265 mg/g phycobiliprotein. In the best buffer pH of on phycobiliproteins extraction was also studied and maximum extraction was achieved at pH-7.0 yielding 146 ±0.265 mg/g phycobiliproteins. The isolated phycocyanin from this process also showed highest purity of 3.2 based on absorbance of 0.026 at 280 nm and 0.065 at 615nm. Freezing at –20 0 C for 3hr and thawing at 4oC for 5min was found to be optimal for highest phycocyanin yield. A polypeptide unit of the phycocyanin was isolated, and their molecular weight was 14 kDa, respectively. These weights are consistent with those of previous reports. This finding suggests that the freezing and thawing process enabled isolation of a stable, highly purified phycocyanin with a short treatment 3cycle (-20 o C with time interval 3 h) as 146 mg/g whose value is 8% to 10% higher than is the case from another conventional separation method using