An environmentally-friendly fluorescent method for quantification of lipid contents in yeast

• Published in: Bioresource technology 2014-01, Vol.151, p.388-391
• Main Authors: Poli, Jandora Severo, Lützhøft, Hans-Christian Holten, Karakashev, Dimitar Borisov, Valente, Patricia, Angelidaki, Irini
• Format: Article
• Language: English
• Subjects: Biodiesel; Biofuel production; Biological and medical sciences; Biotechnology; Calibration; Energy; Fluorescence; Fundamental and applied biological sciences. Psychology; Green Chemistry Technology - methods; Industrial applications and implications. Economical aspects; Lipid; Lipids; Lipids - analysis; Nile red; Optimization; Oxazines - metabolism; Quantification; Saline; Solvents; Solvents - pharmacology; Strain; Yarrowia - cytology; Yarrowia - drug effects; Yarrowia - metabolism; Yeast
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.09.128

•Nile red staining offers short analysis time for neutral lipid determination in yeast.•Nile red staining is energy efficient and uses minute volumes of organic solvents.•Nile red staining is suitable for fast screening and high-throughput analysis. 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 500μg/L, respectively, were added to washed cells suspended in potassium chloride phosphate buffered saline (PBSKCl). Fluorescence was measured after 10min in the dark. Glyceryltrioleate was used as model lipid and the calibration curve showed linearity (R2=0.994) between 0.50 and 25mg/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.