| Summary: | 碩士 === 臺灣大學 === 漁業科學研究所 === 98 === R-phycocyanin, R-PC, R-phycoerythrin, R-PE and allophycocyanin, APC are the photosynthetic accessory pigments of the red algae. As good fluorescent pigments and natural dyes, they have been applied in food, cosmetics and medical diagnostic reagents. Recently we found the immunological modulation bioactivity of R-PC, so as, tried to isolate more of this protein for further characterization studies. In this study, the Con-chocelis phase of Bangia atropurpurea was used for phycobiliprotein extraction. Am-monium sulfate salting-out and gel filtration chromatography, alter a series of R-PC was isolated and subject to a chromatographic purification by a hydroxylapatite column with a two-step gradient elution of K-phosphate buffers. Pure R-PC obtained had an absorb-ance ratio A618/A280 of 4.11. The purple fluorescent protein, R-PC was identified by its two major absorption peaks at 553 and 618 nm. The emission spectra of R-PC obtained had a maximal peak at 640 nm under excitation at 618 nm. From SDS-PAGE, R-PC was determined to consist of α and β subunits of molecular weights of 17.40 and 21.72 kDa, respectively. Both gel electrophoresis and spectroscopic data showed the purity of R-PC through the designed operation. In the same process, fractions, obtained alter gel filtration (A565/A280=6.14), showed the typical spectroscopic characters of R-PE, maxi-mal absorptions were detected at 497, 543 and 565 nm and emission at 574 nm. Allo-phycocyanin was also obtained with fractions (A650/A280=4.18) after R-PC in separation and determined the maximal absorption at 650 nm and emission 660 nm. In order to know the effect of light quality on the growth and comparison of biliproteins, B. atro-purpurea Conchocelis cultures were exposed to white, blue, green and red light in a 22-days experiment. Red light resulted in the lowest production of algal biomass and blue and green light illumination had no different in growth from the white light. R-phycoerythrin content was not affected by light quality, whereas R-phycocyanin and allophycocyanin content were enhanced by blue or red light. Green light increased the content of chlorophyll a.
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