Phycocyanin from a cyanobacterium of Sundarbans

Abstract

Cyanobacteria comprise of a varied bacterial phylum that are responsible for the oxygenation of the environment. Cyanobacteria perform 10 to 25 % of total photosynthesis. The main photosynthetic accessory pigments in cyanobacteria are phycobiliproteins. One of the different types of phycobiliprotein is Phycocyanin (λ_maxat 620 nm). Cyanobacteria possess not only antioxidant protection, but it has been seen to be responsible for anti-inflammatory activities. World’s one of the biggest mangrove forests is Sundarbans in the Bay of Bengal. We have isolated phycocyanin from a cyanobacteria strain, AP9F (GenBank accession number FJ847844). Ammonium sulphate was used for sequential precipitation of crude extract. Increased purity ratio of phycocyanin was achieved through dialysis of the protein sample, anion exchange chromatography using a DE 52 column and Sephadex G-100 column chromatography. The protein consists of two subunits of ɑ (20 kDa) and β (25 kDa) each in (ɑβ) ₂ dimer association. The molecular weight of purified PC was found to be 90 kDa. Antioxidant activity was shown by the purified CPC. Increase in PC concentration decreased the rate of haemolysis. We hereby suggest that the phycocyanin isolated is quite similar other phycocyanin from various freshwater as well as marine cyanobacteria.