title: Oxygen-induced expression of Delta(6)-, Delta(9)- and Delta(12)-desaturase genes modulates fatty acid composition in Mucor rouxii.
abstract: The effect of oxygen availability on the molecular mechanisms of fatty acid biosynthesis was investigated in Mucor rouxii, a Mucorale fungus capable of producing gamma-linolenic acid through perturbation of the gaseous environment. Shifting of the M. rouxii culture from anaerobic to aerobic conditions resulted in an increase of the biomass and total fatty acid content of the M. rouxii culture. In addition, the levels of unsaturated fatty acids were enhanced accompanied by a decrease in the levels of medium- and long-chain saturated fatty acids. These results correspond to the levels of expressions of the Delta(9)-, Delta(12)- and Delta(6)-desaturases genes, all of which were coordinately up-regulated after the shift. The transcriptional response observed was rapid and transient, with the maximal mRNA levels detected between 0.5 h and 1.0 h after the shift. Together, our findings indicate that the anaerobic M. rouxii culture acclimatised to oxygen exposure by modulating fatty acid composition that was transcriptionally co-regulated by Delta(9)-, Delta(12)- and Delta(6)-desaturase genes.
authors.affiliation: School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand.
authors.forename: Rawisara
authors.initials: R
authors.lastname: Ruenwai
authors.forename: Supapon
authors.initials: S
authors.lastname: Cheevadhanarak
authors.forename: Sansanalak
authors.initials: S
authors.lastname: Rachdawong
authors.forename: Morakot
authors.initials: M
authors.lastname: Tanticharoen
authors.forename: Kobkul
authors.initials: K
authors.lastname: Laoteng
mesh_terms: D000332:Aerobiosis; D001709:Biotechnology; D003470:Culture Media; D044943:Fatty Acid Desaturases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects*; D009089:Mucor / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development*; D010100:Oxygen / Q000494:pharmacology*; D017965:gamma-Linolenic Acid / Q000096:biosynthesis
chemical_list: D003470:Culture Media; D005227:Fatty Acids; D017965:gamma-Linolenic Acid; D044943:Fatty Acid Desaturases; D010100:Oxygen