摘要：R-phycoerythrin, which is a light-harvesting protein in some of marine algae, was isolated and purified from red alga, Gracilaria verrucosa, using the STREAMLINE column (expanded bed adsorption) combined with an ion-exchange chromatography. Because the crude extract was applied to the column with an upward direction, the expanded bed adsorption column can effectively overcome the blockage of a general chromatography column from rich polysaccharides in extract of marine algae. Followed by applying the crude extract containing 0.5 mol/M (NH4)2SO4, some different concentration of (NH4)2SO4 solution (0.2 mol/L, 0.1 mol/L and 0.05 mol/L) was used to apply to the column with a reverse direction (in a downward direction) and 0.1 mol/L (NH4)2SO4 was proved best to elute R-phycoerythrin from the STREAMLINE column. The desalted eluate with 0.1 mol/L (NH4)2SO4 was applied into a ion-exchange chromatography column loaded with Q-sepharose to continue to purify the R-phycoerythrin. Through the two steps for isolation and purification, purity ( OD565/OD280) of the R-phycoerythrin from Gracilaria verrucosa is up to 4.4 which is much more than 3.2, a criterion for purity, and the yield of the purified R-phycoerythrin can reach 0.141 mg per gram of frozen Gracilaria verrucosa, which is much higher than the yield of phycobiliproteins purified with the already known methods. The result indicates that the price of R-phycoerythrin will be dropped down if using the method reported in this article.
