Efficient separation and purification of allophycocyanin from Spirulina (Arthrospira) platensis

Abstract

Allophycocyanin (APC) is a minor component of phycobiliproteins in cyanobacteria and red algae. This paper describes a simple and inexpensive extracting method for isolating APC from Spirulina (Arthrospira) platensis with high efficiency. The crude phycobiliprotein extract was pretreated by ammonium sulfate fractionation. Then, by adding hydroxylapatite into crude phycobiliprotein extract dissolved in 20 mM phosphate buffer (pH 7.0), APC was selectively adsorbed by hydroxylapatite but C-phycocyanin (C-PC) was not. The hydroxylapatite was collected and APC was extracted from the crude phycobiliprotein extract. Then, the enriched APC was washed off from the hydroxylapatite using 100 mM phosphate buffer (pH 7.0). In this simple extracting method it was easy to remove C-PC and isolate APC in large amounts. The absorbance ratio A 650 /A 280 of extracted APC reached 2.0. The recovery yield was 70%, representing 4.61 mg·g −1 wet weight. The extracted APC could be further purified by a simple anion-exchange chromatography with a pH gradient from 5.6 to 4.0. The absorbance ratio A 650 /A 280 of the purified APC reached 5.0, and the overall recovery yield was 43%, representing 2.83 mg·g −1 wet weight. Its purity was confirmed by native polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate-PAGE.

Single-step chromatography for simultaneous purification of C-phycocyanin and allophycocyanin with high purity and recovery from Spirulina (Arthrospira) platensis

“…Su et al (2010) proposed hydroxyapatite chromatography combined with anion exchange chromatography for the efficient purification of APC. The method reported here for simultaneous purification of C-PC and APC shows higher efficiency and lower production costs than previously reported methods (Zhang and Chen 1999).…”

“…The crude extract was fractionated with solid ammonium sulfate, first at 25% then at 60% saturation (w/v). The precipitate from 60% saturation was dissolved in a small volume of sodium acetate buffer and dialyzed against the same buffer overnight (Su et al 2010). …”

Isolation and purification of food‐grade C‐phycocyanin from Arthrospira platensis and its determination in confectionery by HPLC with diode array detection

“…The protein content of Spirulina ranges between 50 and 70% of its dry weight [1]. C-Phycocyanin (C-PC) is the major protein, especially phycobiliprotein, in Spirulina [1,2]. Moreover, other phycobiliproteins produced or unsafe [9][10][11][12].…”

Phycobilisome composition in Chondrus crispus (Gigartinales, Rhodophyta) from a wild type strain and its vegetatively derived green mutant

“…The blue band from the green Chondrus strain contained twice as much APC as the purple band, suggesting that APC functioned more in the energy absorption and transfer in the absence of significant amounts of PE. Based upon its absorption spectrum, the APC in the blue extract was determined to be in its trimeric form, and SDS-PAGE confirmed the purity of the APC by elucidating the α and β subunits (Su et al 2010a). This, along with the increased concentration, would help account for the more pronounced staining of the APC components in the SDS-PAGE analysis of the blue band (Fig.…”