Extraction and Native PAGE Separation of Phycobiliproteins from Some Cyanobacteria Collected from Their Natural Habitats

Phycobiliproteins are a group of coloured proteins present in cyanobacteria and algae. They can be divided into three types based on their absorption spectra. These are phycocyanin, phycoerythrin and allophycocyanin. These pigment proteins are used as potential natural colorant in chewing gums, candies, soft drinks, dairy products and cosmetics like lipstick and eyeliners. They are also extensively commercialized for fluorescent applications in clinical immunological analysis. The phycobiliproteins from cyanobacteria have also been reported to have ant-cancerous, anti-inflammatory and antioxidant properties. In view of the increasing demand of these fluorescent pigments, it becomes important to find new species of cyanobacteria and exploit them for their phycobiliprotein content. In present work some commonly available cyanobacteria were collected from their natural habitats and analysed for their phycobiliprotein content. The extraction of phycobiliprotein was done in phosphate buffer and quantitative analysis of the pigment components was done. The study showed that all the cyanobacteria are the potential source of phycocyanin whereas phycoerythrin is significantly present in species of Lyngbya and Oscillatoria. The phycobiliprotein components were separated on Native PAGE which can be partially purified by electroelution. The percentage loss of phycobiliprotein content in stored cyanobacterial biomass for two months showed that phycoerythrin was more stable in Lyngbya and Oscillatoria as compared to the phycocyanin. The species of Scytonema showed good amount of phycocyanin content whereas allophycocyanin was significantly present and was stable in Aulosira sp.