Ethanol-induced changes in expression profiles of cell growth, fatty acid and desaturase genes of Mucor rouxii.
We investigated the response of Mucor rouxii to ethanolic stress conditions. A differential response was found that was dependent on growth phase and ethanol concentration. 5% (v/v) ethanol showed an inhibitory effect on the mycelial growth of all stages. However, the ethanol sensitivity was specifically observed in active growing phases (12 and 21 h-grown cultures), in which the biomass and ratio of unsaturated/saturated fatty acids (UFA/SFA) decreased greatly after ethanol exposure compared to non-ethanol adding culture. With respect to different ethanol concentrations, M. rouxii was tolerant to low ethanol concentrations (about 1-3%, v/v) such that there was not much change in biomass and UFA/SFA ratio, in contrast to the 5% ethanol-added culture. We also showed the molecular basis of this response mechanism, demonstrating that expression of Delta(9)-, Delta(12)- and Delta(6)-desaturase genes, responsible for fatty acid desaturation in M. rouxii, were coordinately down-regulated upon exposure to ethanol stress.
Laoteng
Kobkul
K
Biochemical Engineering and Pilot Plant Research and Development Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC) at King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand.
Jitsue
Sompit
S
Dandusitapunth
Yuwapin
Y
Cheevadhanarak
Supapon
S
D004305:Dose-Response Relationship, Drug; D000431:Ethanol; D044943:Fatty Acid Desaturases / Q000235:genetics*; D005227:Fatty Acids / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D009089:Mucor / Q000502:physiology*; D025282:Mycelium / Q000187:drug effects / Q000254:growth & development; D013997:Time Factors
D005227:Fatty Acids; D000431:Ethanol; D044943:Fatty Acid Desaturases