title: Metabolic engineering of a Saccharomyces cerevisiae strain capable of simultaneously utilizing glucose and galactose to produce enantiopure (2R,3R)-butanediol.
abstract: 2,3-Butanediol (BDO) is an important chemical with broad industrial applications and can be naturally produced by many bacteria at high levels. However, the pathogenicity of these native producers is a major obstacle for large scale production. Here we report the engineering of an industrially friendly host, Saccharomyces cerevisiae, to produce BDO at high titer and yield. By inactivation of pyruvate decarboxylases (PDCs) followed by overexpression of MTH1 and adaptive evolution, the resultant yeast grew on glucose as the sole carbon source with ethanol production completely eliminated. Moreover, the pdc- strain consumed glucose and galactose simultaneously, which to our knowledge is unprecedented in S. cerevisiae strains. Subsequent introduction of a BDO biosynthetic pathway consisting of the cytosolic acetolactate synthase (cytoILV2), Bacillus subtilis acetolactate decarboxylase (BsAlsD), and the endogenous butanediol dehydrogenase (BDH1) resulted in the production of enantiopure (2R,3R)-butanediol (R-BDO). In shake flask fermentation, a yield over 70% of the theoretical value was achieved. Using fed-batch fermentation, more than 100g/L R-BDO (1100mM) was synthesized from a mixture of glucose and galactose, two major carbohydrate components in red algae. The high titer and yield of the enantiopure R-BDO produced as well as the ability to co-ferment glucose and galactose make our engineered yeast strain a superior host for cost-effective production of bio-based BDO from renewable resources.
authors: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Energy Biosciences Institute, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
authors: Jiazhang
authors: J
authors: Lian
authors: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Energy Biosciences Institute, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
authors: Ran
authors: R
authors: Chao
authors: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Energy Biosciences Institute, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Departments of Chemistry, Biochemistry, and Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States. Electronic address: zhao5@illinois.edu.
authors: Huimin
authors: H
authors: Zhao
mesh_terms: D000095:Acetolactate Synthase / Q000096:biosynthesis / Q000235:genetics; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000096:biosynthesis / Q000235:genetics; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D002072:Butylene Glycols / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000096:biosynthesis / Q000235:genetics; D019020:Directed Molecular Evolution / Q000379:methods; D005690:Galactose / Q000378:metabolism* / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D060847:Metabolic Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D013549:Sweetening Agents / Q000378:metabolism / Q000494:pharmacology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D001426:Bacterial Proteins; D002072:Butylene Glycols; C118806:MTH1 protein, S cerevisiae; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D013549:Sweetening Agents; C026978:2,3-butylene glycol; D000429:Alcohol Oxidoreductases; C019801:butanediol dehydrogenase; D000095:Acetolactate Synthase; D002262:Carboxy-Lyases; C023746:acetolactate decarboxylase; D005947:Glucose; D005690:Galactose
keywords: (2R,3R)-Butanediol; Glucose derepression; Metabolic engineering; Pyruvate decarboxylase; Sugar co-utilization