title: Fed-batch fermentation and supercritical fluid extraction of heterotrophic microalgal Chlorella protothecoides lipids.
abstract: Lipids obtained from Chlorella protothecoides in heterotrophic cultivation are considered a suitable feedstock for biodiesel production. In this study, glucose fed-batch fermentation was performed to increase final biomass and lipid production. The biomass productivity and lipid productivity were 6.28 and 2.06 g/L day, respectively. Biomass/glucose conversion and the lipid/glucose conversion were 43.3% and 14.2%, respectively. Extraction of lipids from algae has been identified as a key bottleneck in bioprocessing operations. Supercritical carbon dioxide (SC-CO(2)) was applied for neutral lipids extraction and the SC-CO(2) kinetics was investigated by the Goto et al. model. The modeling showed a good fit with experimental data. Additionally, neutral lipids extracted by SC-CO(2) displayed a suitable fatty acid profile for biodiesel [mainly C18:1 (60.0%), C18:2 (18.7%) and C16:0 (11.5%)]. Our study demonstrated the ability to produce high levels of neutral lipids through heterotrophic algal culture and subsequent extraction of lipids with SC-CO(2) method developed.
authors.affiliation: Biosystems Engineering, Clemson University, Biosystems Research Complex, 105 Collings St., Clemson, SC 29634, USA. ychen@clemson.edu
authors.forename: Yen-Hui
authors.initials: YH
authors.lastname: Chen
authors.forename: Terry H
authors.initials: TH
authors.lastname: Walker
mesh_terms: D061249:Batch Cell Culture Techniques / Q000379:methods*; D019149:Bioreactors / Q000382:microbiology*; D002708:Chlorella / Q000145:classification / Q000378:metabolism*; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D050356:Lipid Metabolism / Q000502:physiology*; D008055:Lipids / Q000302:isolation & purification*; D013045:Species Specificity
chemical_list: D008055:Lipids