Extraction and purificati on of phycoerythrin (a purple natural pigment) from Nostoc sp. Cyanobacterium

Cyanobacteria are the photosynthetic prokaryotes. Nowadays, there has been an in creasing awareness on cyanobacteria as a possible source for new antioxidant. The use of artificial oxidants has reduced due to their carcinogenic nature. So, there is crucial need to substitute them with new harmless natural antioxidants. The potential of soil cyanobacteria as ant ioxidants agents has not been explored yet in Iran. Hence, the present study was focused on purification process of phycoerythrin from a strain of Nostoc sp. and evaluating its antioxidant activi ty. The strain (Nostoc sp. FA1) was collected from the Cyanobacteria Culture Collection (CCC) of herbarium ALBORZ at the Science a nd Research Branch, Islamic Azad University, Teheran. The protocol developed in this study h as four major steps viz. preparation of crude extract (Step I), 65% ammonium sulfate precipit ation (Step II), dialysis (Step III) and anion exchange chromatography (STEP IV) using DEAE-Cellulose-11 and Acetate buffer. Antioxidant activity was determined by free radical scaven ging activity. The purity of the solution during the purification steps was measured using OD at 280 and 562 wavelengths, respectively. The results showed that OD at extraction stage was 1.92 a nd 1.36, respectively, in the ammonium sulfate stage, 3.05 and 4.73 respectively, in the dialysis s tage 2.88 and 4.81, respectively. Through chrom atography an 80 % recovery of phycocyanin with a purity of 4.5 (A620/A280) was achieved. In SDS_PAGE analysis, the purified PC showed the presence of two subunit a (16 kD) and b (17 kD ). Results have shown that the more the substanc e is pure; the density of the color will decrease due to the rise in antioxidant activity. Amidst a large array of natural produ cts produced by cyanobacteria, phycoerythrin seems to be most colorful and attractive componen ts due to their potential application in pharmaceutical and food industries. However, toxicolo gical studies must be carried out to asse ss their biotechnological feasibility for food production

Cyanobacteria are the photosynthetic prokaryotes. Nowadays, there has been an in creasing awareness on cyanobacteria as a possible source for new antioxidant. The use of artificial oxidants has reduced due to their carcinogenic nature. So, there is crucial need to substitute them with new harmless natural antioxidants. The potential of soil cyanobacteria as ant ioxidants agents has not been explored yet in Iran. Hence, the present study was focused on purification process of phycoerythrin from a strain of Nostoc sp. and evaluating its antioxidant activi ty. The strain (Nostoc sp. FA1) was collected from the Cyanobacteria Culture Collection (CCC) of herbarium ALBORZ at the Science a nd Research Branch, Islamic Azad University, Teheran. The protocol developed in this study h as four major steps viz. preparation of crude extract (Step I), 65% ammonium sulfate precipit ation (Step II), dialysis (Step III) and anion exchange chromatography (STEP IV) using DEAE-Cellulose-11 and Acetate buffer. Antioxidant activity was determined by free radical scaven ging activity. The purity of the solution during the purification steps was measured using OD at 280 and 562 wavelengths, respectively. The results showed that OD at extraction stage was 1.92 a nd 1.36, respectively, in the ammonium sulfate stage, 3.05 and 4.73 respectively, in the dialysis s tage 2.88 and 4.81, respectively. Through chrom atography an 80 % recovery of phycocyanin with a purity of 4.5 (A620/A280) was achieved. In SDS_PAGE analysis, the purified PC showed the presence of two subunit a (16 kD) and b (17 kD ). Results have shown that the more the substanc e is pure; the density of the color will decrease due to the rise in antioxidant activity. Amidst a large array of natural produ cts produced by cyanobacteria, phycoerythrin seems to be most colorful and attractive componen ts due to their potential application in pharmaceutical and food industries. However, toxicolo gical studies must be carried out to asse ss their biotechnological feasibility for food production