Extraction, Purification and Spectroscopic Characterization of Phycobiliproteins Extracted from some Nostoc Spp.

Abstract

Phycocyanin and phycoerythrin are considered the major phycobiliprotein in many cyanobacteria as well as being a secondary phycobiliprotein in some red algae. In this article, the biomass of Nostoc linckia was harvested at the 16 th day, which approximately equalled 361 mg/L dry biomass for attaining the maximum content of phycocyanin, and the biomass of Nostoc carneum was collected at the 17 th day that approximately equalled 326 mg/L dry biomass for attaining the maximum content of phycoerythrin. Phycocyanin and phycoerythrin were extracted from both Nostoc linckia and Nostoc carneum respectively. They were extracted by successive cycles of freezing and thawing using 50 mM phosphate buffer solution (pH 7) then purified by single step of precipitation in 65 % of ammonium sulphate. Phycocyanin and phycoerythrin achieved 2.29 and 3.02 of purity ratio; respectively. The purified phycocyanin and phycoerythrin exhibited maximum absorbance at 614 and 560 nm respectively.