Production, extraction and purification of phycobiliproteins from Nostoc sp.

One strain of nitrogen-fixing cyanobacterium (Nostoc sp. PCC 9202) was grown indoors in 1 litre glass air-lift reactors as well as 17 litre polyethylene bags. Temperature dependence of growth-kinetic parameters, as well as of biomass and phycobiliprotein productivities, were determined. Harvesting and phycobiliprotein extraction methodologies are presented. The purification of crude extracts was performed by means of ultrafiltration or (NH4)2SO4 precipitation followed by gel filtration and ion-exchange chromatography. Final phycocyanin and phycoerythrin preparations were characterized by purity ratios above 4 and 5, respectively. Phycobiliprotein production cost determination for each purity grade and cumulative phycobiliprotein weight losses along purification steps are shown. Production cost for high purity phycoerythrin (30 US$ per g) seems to be far below the market price.