title: Extraction of hydrocarbons from microalga Botryococcus braunii with switchable solvents.
abstract: Lipid extraction is a critical step in the development of biofuels from microalgae. Here a new procedure was proposed to extract hydrocarbons from dried and water-suspended samples of the microalga Botryococcus braunii by using switchable-polarity solvents (SPS) based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) and an alcohol. The high affinity of the non-ionic form of DBU/alcohol SPS towards non-polar compounds was exploited to extract hydrocarbons from algae, while the ionic character of the DBU-alkyl carbonate form, obtained by the addition of CO(2), was used to recover hydrocarbons from the SPS. DBU/octanol and DBU/ethanol SPS were tested for the extraction efficiency of lipids from freeze-dried B. braunii samples and compared with n-hexane and chloroform/methanol. The DBU/octanol system was further evaluated for the extraction of hydrocarbons directly from algal culture samples. DBU/octanol exhibited the highest yields of extracted hydrocarbons from both freeze-dried and liquid algal samples (16% and 8.2% respectively against 7.8% and 5.6% with n-hexane).
authors.affiliation: Interdepartmental Research Centre for Environmental Sciences (CIRSA), University of Bologna, via S. Alberto 163, 48123 Ravenna, Italy. chiara.samori3@unibo.it
authors.forename: Chiara
authors.initials: C
authors.lastname: Samorì
authors.forename: Cristian
authors.initials: C
authors.lastname: Torri
authors.forename: Giulia
authors.initials: G
authors.lastname: Samorì
authors.forename: Daniele
authors.initials: D
authors.lastname: Fabbri
authors.forename: Paola
authors.initials: P
authors.lastname: Galletti
authors.forename: Franca
authors.initials: F
authors.lastname: Guerrini
authors.forename: Rossella
authors.initials: R
authors.lastname: Pistocchi
authors.forename: Emilio
authors.initials: E
authors.lastname: Tagliavini
mesh_terms: D020003:1-Octanol / Q000737:chemistry*; D018533:Biomass; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D000460:Chlorophyta / Q000737:chemistry* / Q000166:cytology; D003470:Culture Media; D005227:Fatty Acids / Q000032:analysis; D005612:Freeze Drying; D006586:Hexanes / Q000737:chemistry; D006838:Hydrocarbons / Q000302:isolation & purification*; D008055:Lipids / Q000302:isolation & purification; D012997:Solvents / Q000737:chemistry*
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D003470:Culture Media; D005227:Fatty Acids; D006586:Hexanes; D006838:Hydrocarbons; D008055:Lipids; D012997:Solvents; C026385:n-hexane; C031033:1,8-diazabicyclo(5.4.0)undec-7-ene; D020003:1-Octanol