JOURNAL OF APPLIED PHYCOLOGY, cilt.30, sa.3, ss.1513-1523, 2018 (SCI-Expanded)
Phycobiliproteins, light-harvesting pigments found in cyanobacteria and in some eukaryotic algae, have numerous commercial applications in food, cosmetic, and pharmaceutical industries. Colorant production from cyanobacteria offers advantages over their production from higher plants, as cyanobacteria have fast growth rate and high photosynthetic efficiency and require less space. In this study, three cyanobacteria strains were studied for phycobiliprotein production and the influence of sodium nitrate, potassium nitrate and ammonium chloride on the growth and phycobiliprotein composition of the strains were evaluated. In the batch culture period of 12 days, Phormidium sp. and Pseudoscillatoria sp. were able to utilize all tested nitrogen sources; however, ammonium chloride was the best nitrogen source for both strains to achieve maximum growth rate mu = 0.284 +/- 0.03 and mu = 0.274 +/- 0.13 day(-1), chlorophyll a 16.2 +/- 0.5 and 12.2 +/- 0.2 mg L-1, and phycobiliprotein contents 19.38 +/- 0.09 and 19.99 +/- 0.14% of dry weight, whereas, for Arthrospira platensis, the highest growth rate of mu = 0.304 +/- 0.0 day(-1), chlorophyll a 19.1 +/- 0.5 mg L-1, and phycobiliprotein content of 22.27 +/- 0.21% of dry weight were achieved with sodium nitrate. The phycocyanin from the lyophilized cyanobacterial biomass was extracted using calcium chloride and food grade purity (A (620)/A (280) ratio > 0.7) was achieved. Furthermore, phycocyanin was purified using two-step chromatographic method and the analytical grade purity (A (620)/A (280) ratio > 4) was attained. SDS-PAGE demonstrated the purity and presence of two bands corresponding to alpha- and beta-subunits of the C-phycocyanin. The results showed that Phormidium sp. and Pseudoscillatoria sp. could be good candidates for phycocyanin production.