Combined freeze–thaw-ultrasound assisted method for the extraction of crude phycoerythrin from Porphyridium cruentum
摘要
Phycoerythrin, a phycobiliprotein from the microalga Porphyridium cruentum, is a fluorescent pink pigment with growing demand in various industries. A wide range of extraction methods like solvent extraction, maceration, microwave and pulsed electric-field assisted extraction methods have been investigated for the extraction of phycoerythrin. Nevertheless, using just one technique alone can account for reduced yield and difficulty in scalability. Hence, this study was an attempt to maximize the yield of phycoerythrin using combination methods of freeze–thaw and ultrasonication, which can be adapted by the industry. It was found that both yield and concentration of phycoerythrin varied with variation in the sequence of freeze–thaw and ultrasonication methods. The yield of phycoerythrin from dried microalgal biomass ranged from 2.80 to 8.15 mg g−1. The highest yield of crude phycoerythrin was obtained through the combination method of two freeze–thaw cycles, along with ultrasonication (yield, 8.15 ± 3.99 mg g−1 of dried microalgal biomass and concentration in buffer, 0.41 ± 1.75 mg mL−1). Though the purity ratio increased with concentration and yield, it did not show significant differences within the treatments. According to the study, freeze–thaw combined with ultrasonication assistance may increase the yield and concentration of crude phycoerythrin. The process needs to be optimized for the highest yield in the shortest amount of time for industrial scale-up.