title: Xylose-fermenting Pichia stipitis by genome shuffling for improved ethanol production.
abstract: Xylose fermentation is necessary for the bioconversion of lignocellulose to ethanol as fuel, but wild-type Saccharomyces cerevisiae strains cannot fully metabolize xylose. Several efforts have been made to obtain microbial strains with enhanced xylose fermentation. However, xylose fermentation remains a serious challenge because of the complexity of lignocellulosic biomass hydrolysates. Genome shuffling has been widely used for the rapid improvement of industrially important microbial strains. After two rounds of genome shuffling, a genetically stable, high-ethanol-producing strain was obtained. Designated as TJ2-3, this strain could ferment xylose and produce 1.5 times more ethanol than wild-type Pichia stipitis after fermentation for 96 h. The acridine orange and propidium iodide uptake assays showed that the maintenance of yeast cell membrane integrity is important for ethanol fermentation. This study highlights the importance of genome shuffling in P. stipitis as an effective method for enhancing the productivity of industrial strains.
authors.affiliation: Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Shi
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Libin
authors.initials: L
authors.lastname: Zhang
authors.forename: Pin
authors.initials: P
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Jiang
authors.forename: Huiping
authors.initials: H
authors.lastname: Deng
mesh_terms: D000165:Acridine Orange / Q000378:metabolism; D002462:Cell Membrane / Q000502:physiology; D032621:DNA Shuffling; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D007218:Industrial Microbiology; D060847:Metabolic Engineering; D010843:Pichia / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D011419:Propidium / Q000378:metabolism; D013194:Staining and Labeling; D014994:Xylose / Q000378:metabolism*
chemical_list: D011419:Propidium; D000431:Ethanol; D014994:Xylose; D000165:Acridine Orange