Sonoprocessing-assisted solvent extraction for the recovery of pigment-protein complex from Spirulina platensis

Current practice for C-phycocyanin (CPC) extraction from fresh biomass is greatly perishable, so dried biomass is preferable for longer storage life and saving spaces for small scale industries. However, the resistance of dried biomass towards cell disruption is higher compared to fresh biomass. Therefore, this work aims to develop an effective technique for the extraction of CPC from dried Spirulina sp. This study addresses the effect of sonoprocessing-assisted with liquid biphasic flotation (LBF) for the extraction and purification of CPC and allophycocyanin (APC). The application of ultrasound was optimized by various parameters such as amplitude (20 to 30%), sonication time in pulse mode (5 to 25 s), resting time in pulse mode (5 to 25 s) and the total time of sonication (3 to 12 min). While for the liquid biphasic flotation, the studied parameters were air flowrate (75 to 175 cc/min), a volume ratio of both phases (1:0.5 to 1:1.5), flotation time (3 to 12 min), and weight of biomass (0.1 to 0.6 g). Results of both CPC and APC were determined using the optimized conditions and subjected to SDS-PAGE analysis. Total purification factor of 5.23 and recovery of 95.10% were obtained using 30% amplitude, 5 s ON/5s OFF (pulse mode), 10 min sonication, volume ratio 1:1, 100 cc/min air flowrate, 7 min flotation time, and 0.45 g biomass. This study proves that the suggested method enhances efficiency in the recovery of CPC and demonstrates the synergistic effect of sonoprocessing with LBF in extracting CPC and other biomolecules from microalgae.