title: The combination of glycerol metabolic engineering and drug resistance marker-aided genome shuffling to improve very-high-gravity fermentation performances of industrial Saccharomyces cerevisiae.
abstract: A challenge associated with the ethanol productivity under very-high-gravity (VHG) conditions, optimizing multi-traits (i.e. byproduct formation and stress tolerance) of industrial yeast strains, is overcome by a combination of metabolic engineering and genome shuffling. First, industrial strain Y12 was deleted with a glycerol exporter Fps1p and hetero-expressed with glyceraldehydes-3-phosphate dehydrogenase, resulting in the modified strain YFG12 with lower glycerol yield. Second, YFG12 was subjected to three rounds of drug resistance marker-aided genome shuffling to increase its ethanol tolerance, and the best shuffled strain TS5 was obtained. Compared with wild strain Y12, shuffled strain TS5 not only decreased glycerol formation by 14.8%, but also increased fermentation rate and ethanol yield by 3.7% and 7.6%, respectively. Moreover, the system of genetic modification and Cre/loxP in aid of three different drug-resistance markers presented in the study significantly improved breeding efficiency and will facilitate the application of breeding technologies in prototrophic industrial microorganisms.
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, 310058 Zhejiang, PR China.
authors.forename: Pin-Mei
authors.initials: PM
authors.lastname: Wang
authors.forename: Dao-Qiong
authors.initials: DQ
authors.lastname: Zheng
authors.forename: Tian-Zhe
authors.initials: TZ
authors.lastname: Liu
authors.forename: Xiang-Lin
authors.initials: XL
authors.lastname: Tao
authors.forename: Ming-Guang
authors.initials: MG
authors.lastname: Feng
authors.forename: Hang
authors.initials: H
authors.lastname: Min
authors.forename: Xin-Hang
authors.initials: XH
authors.lastname: Jiang
authors.forename: Xue-Chang
authors.initials: XC
authors.lastname: Wu
mesh_terms: D000704:Analysis of Variance; D017931:DNA Primers / Q000235:genetics; D025141:Drug Resistance, Fungal / Q000235:genetics; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000235:genetics / Q000502:physiology; D016681:Genome, Fungal / Q000235:genetics*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism*; D007218:Industrial Microbiology / Q000379:methods*; D060847:Metabolic Engineering / Q000379:methods*; D016296:Mutagenesis; D010957:Plasmids / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D000431:Ethanol; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D005990:Glycerol