title: An environmentally-friendly fluorescent method for quantification of lipid contents in yeast.
abstract: This study aimed at developing an efficient, fast and environmentally-friendly method to quantify neutral lipid contents in yeast. After optimising the fluorescence instrument parameters and influence of organic solvent concentrations, a new method to quantify neutral lipids in yeast based on fluorescence was demonstrated. Isopropanol and Nile red in concentrations of 5% (final volume%) and 500 μg/L, respectively, were added to washed cells suspended in potassium chloride phosphate buffered saline (PBSKCl). Fluorescence was measured after 10 min in the dark. Glyceryltrioleate was used as model lipid and the calibration curve showed linearity (R(2)=0.994) between 0.50 and 25 mg/L. Compared with traditional gravimetric analysis, the developed method is much faster and uses less organic solvents. Lipid contents determined by fluorescence and gravimetry were the same for some strains, but for other strains the lipid contents determined by fluorescence were less. This new method will therefore be suitable for fast screening purposes.
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kongens Lyngby, Denmark; Department of Microbiology, Immunology and Parasitology, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite, 500 sala 154, Cep: 90050-170 Porto Alegre, RS, Brazil. Electronic address: jandora.poli@gmail.com.
authors.forename: Jandora Severo
authors.initials: JS
authors.lastname: Poli
authors.forename: Hans-Christian Holten
authors.initials: HC
authors.lastname: Lützhøft
authors.forename: Dimitar Borisov
authors.initials: DB
authors.lastname: Karakashev
authors.forename: Patricia
authors.initials: P
authors.lastname: Valente
authors.forename: Irini
authors.initials: I
authors.lastname: Angelidaki
mesh_terms: D005453:Fluorescence; D055772:Green Chemistry Technology / Q000379:methods*; D008055:Lipids / Q000032:analysis*; D010078:Oxazines / Q000378:metabolism; D012997:Solvents / Q000494:pharmacology; D025062:Yarrowia / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
chemical_list: D008055:Lipids; D010078:Oxazines; D012997:Solvents; C044808:nile red
keywords: Biodiesel; Lipid; Nile red; Quantification; Yeast