title: Direct bioethanol production from wheat straw using xylose/glucose co-fermentation by co-culture of two recombinant yeasts.
abstract: To achieve a cost-effective bioconversion of lignocellulosic materials, a novel xylose/glucose co-fermentation process by co-culture of cellulose-utilizing recombinant Saccharomyces cerevisiae (S. cerevisiae) and xylan-utilizing recombinant Pichia pastoris (P. pastoris) was developed, in which ethanol was produced directly from wheat straw without additional hydrolytic enzymes. Recombinant S. cerevisiae coexpressing three types of cellulase and recombinant P. pastoris coexpressing two types of xylanase were constructed, respectively. All cellulases and xylanases were successfully expressed and similar extracellular activity was demonstrated. The maximum ethanol concentration of 32.6 g L-1with the yield 0.42 g g-1was achieved from wheat straw corresponding to 100 g L-1of total sugar after 80 h co-fermentation, which corresponds to 82.6% of the theoretical yield. These results demonstrate that the direct and efficient ethanol production from lignocellulosic materials is accomplished by simultaneous saccharification (cellulose and hemicellulose) and co-fermentation (glucose and xylose) with the co-culture of the two recombinant yeasts.
authors.affiliation: Department of Pharmaceutics, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, 266042, Shandong, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Pharmaceutics, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, 266042, Shandong, China.
authors.forename: Caiyun
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Pharmaceutics, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, 266042, Shandong, China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Pharmaceutics, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, 266042, Shandong, China.
authors.forename: Ruoxin
authors.initials: R
authors.lastname: Yang
authors.affiliation: Department of Pharmaceutics, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, 266042, Shandong, China.
authors.forename: Peilei
authors.initials: P
authors.lastname: Hou
authors.affiliation: Department of Pharmaceutics, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, 266042, Shandong, China. liujh@qust.edu.cn.
authors.forename: Junhong
authors.initials: J
authors.lastname: Liu
mesh_terms: D002482:Cellulose / Q000737:chemistry; D018920:Coculture Techniques; D003362:Cost-Benefit Analysis; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D008031:Lignin / Q000737:chemistry; D000074041:Microorganisms, Genetically-Modified; D010843:Pichia / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry; D015202:Protein Engineering; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D014908:Triticum; D014994:Xylose / Q000378:metabolism
chemical_list: D011134:Polysaccharides; C036909:lignocellulose; D000431:Ethanol; C007916:hemicellulose; D002482:Cellulose; D008031:Lignin; D014994:Xylose; D005947:Glucose
keywords: Bioethanol; Co-fermentation; Recombinant Pichia pastoris; Recombinant Saccharomyces cerevisiae; Simultaneous saccharification; Wheat straw