Efficient accumulation of oleic acid in Saccharomyces cerevisiae caused by expression of rat elongase 2 gene (rELO2) and its contribution to tolerance to alcohols

• Published in: Applied microbiology and biotechnology 2011-09, Vol.91 (6), p.1593-1600
• Main Authors: Yazawa, Hisashi, Kamisaka, Yasushi, Kimura, Kazuyoshi, Yamaoka, Masakazu, Uemura, Hiroshi
• Format: Article
• Language: English
• Subjects: Acetyltransferases - genetics; Acetyltransferases - metabolism; Alcohol; Alcohols; Alcohols - pharmacology; Amino acids; Analysis; Animals; Applied Genetics and Molecular Biotechnology; Biological and medical sciences; Biotechnology; Cloning; Ethanol; Fatty acids; Fatty Acids, Monounsaturated - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression; Genetic engineering; Genomes; Life Sciences; Microbial Genetics and Genomics; Microbiology; Monounsaturated fatty acids; Oleic Acid - metabolism; Plasmids; Rats; Saccharomyces cerevisiae; Saccharomyces cerevisiae - drug effects; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Studies; Yeast
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-011-3410-4

When the cells of Saccharomyces cerevisiae are exposed to high concentration of ethanol, the content of oleic acid (C18:1n-9) increased as the initial concentration of ethanol increased. Based on this observation, we attempted to confer ethanol tolerance to S. cerevisiae by manipulating fatty acid composition of the cells. Rather than altering OLE1 expression [the desaturase making both C16:1n-7 (palmitoleic acid) and C18:1n-9], we introduced elongase genes. Introduction of rat elongase 1 gene ( rELO1 ) into S. cerevisiae gave cis -vaccenic acid ( cis -C18:1n-7) by conversion from C16:1n-7, and the increase in this C18:1 fatty acid did not confer ethanol tolerance to the cells. On the other hand, the introduction of rat elongase 2 gene ( rELO2 ), which elongates C16:0 to C18:0, drastically increased C18:1n-9 content, and the cells acquired ethanol tolerance, emphasizing the specific role of C18:1n-9. Furthermore, the transformant of rELO2 also conferred tolerance to n -butanol, n -propanol, and 2-propanol.