title: Efficient reduction of the formation of by-products and improvement of production yield of 2,3-butanediol by a combined deletion of alcohol dehydrogenase, acetate kinase-phosphotransacetylase, and lactate dehydrogenase genes in metabolically engineered Klebsiella oxytoca in mineral salts medium.
abstract: Klebsiella oxytoca KMS005 (∆adhE∆ackA-pta∆ldhA) was metabolically engineered to improve 2,3-butanediol (BDO) yield. Elimination of alcohol dehydrogenase E (adhE), acetate kinase A-phosphotransacetylase (ackA-pta), and lactate dehydrogenase A (ldhA) enzymes allowed BDO production as a primary pathway for NADH re-oxidation, and significantly reduced by-products. KMS005 was screened for the efficient glucose utilization by metabolic evolution. KMS005-73T improved BDO production at a concentration of 23.5±0.5 g/L with yield of 0.46±0.02 g/g in mineral salts medium containing 50 g/L glucose in a shake flask. KMS005-73T also exhibited BDO yields of about 0.40-0.42 g/g from sugarcane molasses, cassava starch, and maltodextrin. During fed-batch fermentation, KMS005-73T produced BDO at a concentration, yield, and overall and specific productivities of 117.4±4.5 g/L, 0.49±0.02 g/g, 1.20±0.05 g/Lh, and 27.2±1.1 g/gCDW, respectively. No acetoin, lactate, and formate were detected, and only trace amounts of acetate and ethanol were formed. The strain also produced the least by-products and the highest BDO yield among other Klebsiella strains previously developed.
authors.affiliation: Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand. Electronic address: kaemwich@sut.ac.th.
authors.forename: Kaemwich
authors.initials: K
authors.lastname: Jantama
authors.affiliation: Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand.
authors.forename: Pattharasedthi
authors.initials: P
authors.lastname: Polyiam
authors.affiliation: Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand.
authors.forename: Panwana
authors.initials: P
authors.lastname: Khunnonkwao
authors.affiliation: Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand.
authors.forename: Sitha
authors.initials: S
authors.lastname: Chan
authors.affiliation: Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand.
authors.forename: Maytawadee
authors.initials: M
authors.lastname: Sangproo
authors.affiliation: Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand.
authors.forename: Kirin
authors.initials: K
authors.lastname: Khor
authors.affiliation: Division of Biopharmacy, Faculty of Pharmaceutical Sciences, Ubon Ratchathani University, Warinchamrap, Ubon Ratchathani 34190, Thailand.
authors.forename: Sirima Suvarnakuta
authors.initials: SS
authors.lastname: Jantama
authors.affiliation: Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand.
authors.forename: Sunthorn
authors.initials: S
authors.lastname: Kanchanatawee
mesh_terms: D000084:Acetate Kinase / Q000235:genetics; D000426:Alcohol Dehydrogenase / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D002072:Butylene Glycols / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry*; D017353:Gene Deletion; D005798:Genes, Bacterial; D041121:Klebsiella oxytoca / Q000235:genetics* / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000235:genetics; D060847:Metabolic Engineering / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; D002072:Butylene Glycols; D003470:Culture Media; C026978:2,3-butylene glycol; D000426:Alcohol Dehydrogenase; D007770:L-Lactate Dehydrogenase; D000084:Acetate Kinase
keywords: 2,3-Butanediol; Klebsiella oxytoca; Metabolic engineering