title: A novel approach for the improvement of ethanol fermentation by Saccharomyces cerevisiae.
abstract: Fermentation properties under the control of multiple genes are difficult to alter with traditional methods in Saccharomyces cerevisiae. Here, a novel genome engineering approach is developed to improve ethanol production in very high gravity fermentation with 300 g/L glucose as the carbon source. This strategy involved constructing aneuploid strains on the base of tetraploid cells. The tetraploid strain was constructed by using the plasmid YCplac33-GHK, which harbored the HO gene encoding the site-specific Ho endonucleases. The aneuploid strain, WT4-M, was selected and screened after the tetraploid cells were treated with methyl benzimidazole-2-yl-carbamate to induce loss of mitotic chromosomes. It was found that aneuploid strain WT4-M not only exhibited an increase in ethanol production and osmotic and thermal tolerance, but also an improvement in the sugar-ethanol conversion rate. Notably, WT4-M provided up to 9.8% improvement in ethanol production compared with the control strain. The results demonstrated that the strategy of aneuploidy was valuable for creating yeast strains with better fermentation characteristics.
authors.affiliation: Tianjin University of Science and Technology, P.R. China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Hou
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Cao
authors.forename: Chunling
authors.initials: C
authors.lastname: Wang
mesh_terms: D000782:Aneuploidy; D015825:Chromosomes, Fungal; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D007218:Industrial Microbiology / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000431:Ethanol; D005947:Glucose