Proteins recovery from wet microalgae using liquid biphasic flotation (LBF)

• Published in: Bioresource technology 2017-11, Vol.244 (Pt 2), p.1329-1336
• Main Authors: Phong, Win Nee, Show, Pau Loke, Teh, Wei Heng, Teh, Tiong Xin, Lim, Hilary Mae Yan, Nazri, Nurul Shafira binti, Tan, Chung Hong, Chang, Jo-Shu, Ling, Tau Chuan
• Format: Article
• Language: English
• Subjects: 2-Propanol; Biomass; Chlorella; Liquid biphasic flotation (LBF); Microalgae; Protein recovery; Recycling; Ultrasonication
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2017.05.165

•Protein was recovered from wet microalgae using alcohol/salt LBF.•The effects of varying parameters were investigated and optimized.•The best system was formed by 250g/L ammonium sulphate and 60% of 2-propanol.•LBF was optimal at 1.0VR,initial, 20g/L crude load, 10min of flotation time.•88.86% of protein was recovered at 3rd recycling process. In this work, the extraction of microalgal protein from wet Chlorella sorokiniana species using alcohol/salt liquid biphasic flotation (LBF) with the aid of ultrasonication for cell rupturing was proposed. The effect of varying crude feedstock concentration, flotation time, salt type, salt concentration, alcohol type, alcohol concentration, initial volumes of salt and alcohol were investigated. After the optimization process, the highest proportion of protein recovered in the top phase was achieved with 250g/L ammonium sulphate, 60% (v/v) 2-propanol, 1.0VR,initial, 20g/L crude biomass load, 4mm3/min air flowrate and 10min of flotation time. The recycling of phase components was introduced to minimize the use of alcohol and salt in the corresponding LBF. It was demonstrated that top phase (alcohol) recycling can achieve increasing performance for three consecutive recycling runs. Under optimized process conditions, the proportion of protein recovered in the top phase was 88.86% for the third recycle run.