title: Random UV-C mutagenesis of Scheffersomyces (formerly Pichia) stipitis NRRL Y-7124 to improve anaerobic growth on lignocellulosic sugars.
abstract: Scheffersomyces (formerly Pichia) stipitis NRRL Y-7124 was mutagenized using UV-C irradiation to produce yeast strains for anaerobic conversion of lignocellulosic sugars to ethanol. UV-C irradiation potentially produces large numbers of random mutations broadly and uniformly over the whole genome to generate unique strains. Wild-type cultures of S. stipitis NRRL Y-7124 were subjected to UV-C (234 nm) irradiation targeted at approximately 40% cell survival. When surviving cells were selected in sufficient numbers via automated plating strategies and cultured anaerobically on xylose medium for 5 months at 28°C, five novel mutagenized S. stipitis strains were obtained. Variable number tandem repeat analysis revealed that mutations had occurred in the genome, which may have produced genes that allowed the anaerobic utilization of xylose. The mutagenized strains were capable of growing anaerobically on xylose/glucose substrate with higher ethanol production during 250- to 500-h growth than a Saccharomyces cerevisiae yeast strain that is the standard for industrial fuel ethanol production. The S. stipitis strains resulting from this intense multigene mutagenesis strategy have potential application in industrial fuel ethanol production from lignocellulosic hydrolysates.
authors: Renewable Product Technology (RPT) Research Unit, National Center for Agricultural Utilization Research (NCAUR), Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Peoria, IL 61604, USA. Stephen.Hughes@ars.usda.gov
authors: Stephen R
authors: SR
authors: Hughes
authors: William R
authors: WR
authors: Gibbons
authors: Sookie S
authors: SS
authors: Bang
authors: Rebecca
authors: R
authors: Pinkelman
authors: Kenneth M
authors: KM
authors: Bischoff
authors: Patricia J
authors: PJ
authors: Slininger
authors: Nasib
authors: N
authors: Qureshi
authors: Cletus P
authors: CP
authors: Kurtzman
authors: Siqing
authors: S
authors: Liu
authors: Badal C
authors: BC
authors: Saha
authors: John S
authors: JS
authors: Jackson
authors: Michael A
authors: MA
authors: Cotta
authors: Joseph O
authors: JO
authors: Rich
authors: Jeremy E
authors: JE
authors: Javers
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D008031:Lignin / Q000378:metabolism; D016296:Mutagenesis; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D004718:Saccharomycetales / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D014466:Ultraviolet Rays; D014994:Xylose / Q000378:metabolism*
chemical_list: C036909:lignocellulose; D000431:Ethanol; D008031:Lignin; D014994:Xylose; D005947:Glucose