title: [Improving ethanol tolerance of Saccharomyces cerevisiae industrial strain by directed evolution of SPT3].
abstract: Directed evolution of transcription factors can be employed to effectively improve the phenotypes which are controlled by multiple genetic loci. In this study, we used error-prone PCR for the directed evolution of SPT3, which is the component of yeast Spt-Ada-Gcn5-acetyltransferase (SAGA) complex responsible for the transcription of stress-related genes, and studied its effect on the improvement of ethanol tolerance. Mutant library was constructed by ligating the error-prone PCR products with a modified pYES2.0 plasmid, and the expression plasmids were subsequently transformed to yeast industrial strain Saccharomyces cerevisiae 4126. One mutant strain M25 showing superior growth in presence of 10% ethanol was selected. M25 produced 11.7% more ethanol than the control strain harboring the empty vector when 125 g/L glucose was used as substrate. This study revealed that SPT3 is an important transcription factor for the metabolic engineering of yeast ethanol tolerance.
authors.affiliation: Department of Bioscience and Bioengineering, Dalian University of Technology, Dalian, China. xqzhao@dlut.edu.cn
authors.forename: Xinqing
authors.initials: X
authors.lastname: Zhao
authors.forename: Rujiao
authors.initials: R
authors.lastname: Jiang
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.forename: Fengwu
authors.initials: F
authors.lastname: Bai
mesh_terms: D019020:Directed Molecular Evolution / Q000379:methods*; D025141:Drug Resistance, Fungal; D004361:Drug Tolerance; D000431:Ethanol / Q000378:metabolism* / Q000494:pharmacology; D007218:Industrial Microbiology / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*
chemical_list: C507785:SAGA complex, S cerevisiae; C075582:SPT3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D000431:Ethanol