Phycocyanins (PCs) are photosynthetic pigments produced by cyanobacteria with great potential for industrial and commercial development due to their antioxidant, antiinflammatory, anti-cancer and hepatoprotective properties. Their market value is estimated to be around 10-50 million US$ per year. Pressure-driven membrane operations represent an useful approach in fractionation, purification and concentration steps of PCs as alternative to expensive sequential purification techniques such as ammonium sulphate precipitation and gel filtration chromatography. In our approach a combination of aqueous extraction and ultrafiltration (UF) was investigated to produce PC with food-grade purity from Spirulina (Arthrospira maxima), a blue-green coil shaped cyanobacterium. The biomass-solvent ratio was optimized in order to maximize the yield of PC in the aqueous extract. 20 kDa flat-sheet membranes and 20 kDa hollow-fiber membranes, operating in dead-end and cross-flow configuration, respectively, were studied to remove non-protein molecules (mainly DNA) from PC in the centrifuged extract. Experiments were performed in batch concentration mode up to a volume concentration factor (VCF) of 5 and the UF retentate was diafiltrated with distilled water in order to enhance the PC purification. Membrane performance was assessed in terms of PC and DNA retention, productivity, fouling index and cleaning efficiency. PC rejections measured in dead-end and cross-flow filtrations with selected membranes were of about 96% and 98%, respectively. According to the mass balance of the process more that 97% of PC was recovered in the UF retentate. Diafiltration allowed to remove more than 90% of the DNA from the crude extract, thereby improving the purity of the PC in the retentate fraction. In both processes the purity degree of the final product resulted higher that 1.1, making it suitable for human food use. Purified PCs have been separated by SDS-PAGE, sequenced by means of mass spectrometry and identified by bioinformatics.
Environmentally friendly extraction of c-phycocyanin from Arthrospira maxima and its purification by ultrafiltration
Conidi Carmela;Figoli Alberto;Cassano Alfredo
2022
Abstract
Phycocyanins (PCs) are photosynthetic pigments produced by cyanobacteria with great potential for industrial and commercial development due to their antioxidant, antiinflammatory, anti-cancer and hepatoprotective properties. Their market value is estimated to be around 10-50 million US$ per year. Pressure-driven membrane operations represent an useful approach in fractionation, purification and concentration steps of PCs as alternative to expensive sequential purification techniques such as ammonium sulphate precipitation and gel filtration chromatography. In our approach a combination of aqueous extraction and ultrafiltration (UF) was investigated to produce PC with food-grade purity from Spirulina (Arthrospira maxima), a blue-green coil shaped cyanobacterium. The biomass-solvent ratio was optimized in order to maximize the yield of PC in the aqueous extract. 20 kDa flat-sheet membranes and 20 kDa hollow-fiber membranes, operating in dead-end and cross-flow configuration, respectively, were studied to remove non-protein molecules (mainly DNA) from PC in the centrifuged extract. Experiments were performed in batch concentration mode up to a volume concentration factor (VCF) of 5 and the UF retentate was diafiltrated with distilled water in order to enhance the PC purification. Membrane performance was assessed in terms of PC and DNA retention, productivity, fouling index and cleaning efficiency. PC rejections measured in dead-end and cross-flow filtrations with selected membranes were of about 96% and 98%, respectively. According to the mass balance of the process more that 97% of PC was recovered in the UF retentate. Diafiltration allowed to remove more than 90% of the DNA from the crude extract, thereby improving the purity of the PC in the retentate fraction. In both processes the purity degree of the final product resulted higher that 1.1, making it suitable for human food use. Purified PCs have been separated by SDS-PAGE, sequenced by means of mass spectrometry and identified by bioinformatics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
