High-efficiency cell disruption and astaxanthin recovery from Haematococcus pluvialis cyst cells using room-temperature imidazolium-based ionic liquid/water mixtures

• Published in: Bioresource technology Vol. 274; pp. 120 - 126
• Main Authors: Choi, Sun-A, Oh, You-Kwan, Lee, Jiye, Sim, Sang Jun, Hong, Min Eui, Park, Ji-Yeon, Kim, Min-Sik, Kim, Seung Wook, Lee, Jin-Suk
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-02-2019
• Subjects: Astaxanthin extraction; Cell disruption; Haematococcus pluvialis cyst; Ionic liquid; Lipid extraction; Lipid extraction; Cell disruption; Haematococcus pluvialis cyst; Astaxanthin extraction; Ionic liquid
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2018.11.082

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•Comparison of imidazolium ionic liquids (ILs) for disruption of H. pluvialis cyst.•Co-extraction of lipid and astaxanthin using room-temperature IL/water mixtures.•Very high astaxanthin recoveries (>99%) by IL pretreatments and hexane extractions.
Energy-saving, high-efficiency cell disruption is a critical step for recovery of thermolabile antioxidant astaxanthin from Haematococcus pluvialis cyst cells of rigid cell-wall structure. In this study, as room-temperature green solvents, 10 types of 1-ethyl-3-methylimidazolium ([Emim])-based ionic liquids (ILs) were compared and evaluated for their abilities to disrupt H. pluvialis cyst cells for astaxanthin/lipid extraction. Among the 10 ILs tested, 3 [Emim]-based ILs with HSO4, CH3SO3, and (CF3SO2)2N anions were selected based on astaxanthin/lipid extraction performance and synthesis cost. When pretreated with IL/water mixtures, intact cyst cells were significantly torn, broken or shown to release cytoplasmic components, thereby facilitating subsequent separation of astaxanthin/lipid by hexane. However, excess IL pretreatments at high temperature/IL dosages and longer incubation times significantly deteriorated lipid and/or astaxanthin. Under optimized mild conditions (6.7% (v/v) IL in water solution, 30 °C, 60 min), almost complete astaxanthin recoveries (>99%) along with moderate lipid extractions (∼82%) could be obtained.