Modified high-throughput Nile red fluorescence assay for the rapid screening of oleaginous yeasts using acetic acid as carbon source

• Published in: BMC microbiology Vol. 20; no. 60; pp. 1 - 11
• Main Authors: Miranda, Catarina, Bettencourt, Sara, Pozdniakova, T. A., Pereira, Joana, Sampaio, Paula, Franco-Duarte, Ricardo, Pais, Célia
• Format: Journal Article
• Language: English
• Published: England BioMed Central (BMC) 14-03-2020; BioMed Central Ltd; BioMed Central; BMC
• Subjects: Acetic acid; Acetic Acid - metabolism; Carbon; Carbon sources; Chemical properties; Chromatography; Composition; Culture Media; Equipment and supplies; Fatty acids; Fluorescence; Fluorescence spectroscopy; Fluorescent Dyes - chemistry; Fourier transforms; High-throughput screening (Biochemical assaying); High-Throughput Screening Assays; Identification and classification; Intracellular lipids; Lipid Metabolism; Lipid research; Lipids; Metabolism; Methods; Microbiology; Microorganisms; Nile red; Nitrogen; Oxazines - chemistry; Petroleum production; Science & Technology; Single cell oils; Soil Microbiology; Staining and Labeling; Volatile fatty acids; Yeast; Yeasts; Yeasts (Fungi); Yeasts - classification; Yeasts - growth & development; Yeasts - isolation & purification; Yeasts - metabolism; Portugal; Nile red; Yeasts; Intracellular lipids; Volatile fatty acids; Single cell oils
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/s12866-020-01742-6

Background: Over the last years oleaginous yeasts have been studied for several energetic, oleochemical, medical and pharmaceutical purposes. However, only a small number of yeasts are known and have been deeply exploited. The search for new isolates with high oleaginous capacity becomes imperative, as well as the use of alternative and ecological carbon sources for yeast growth. Results: In the present study a high-throughput screening comprising 366 distinct yeast isolates was performed by applying an optimised protocol based on two approaches: (I) yeast cultivation on solid medium using acetic acid as carbon source, (II) neutral lipid estimation by fluorimetry using the lipophilic dye Nile red. Conclusions: Results showed that, with the proposed methodology, the oleaginous potential of yeasts with broad taxonomic diversity and variety of growth characteristics was discriminated. Furthermore, this work clearly demonstrated the association of the oleaginous yeast character to the strain level, contrarily to the species-level linkage, as usually stated.
This work was supported by the European project “VOLATILE - Biowaste derived volatile fatty acid platform for biopolymers, bioactive compounds and chemical building blocks “(Call H2020-NMBP-BIO-2016 Grant agreement No. 720777) and by the strategic programme UID/BIA/04050/2013 (POCI-01- 0145-FEDER-007569) funded by national funds through the FCT I.P., by the ERDF through the COMPETE2020.