title: High production of 2,3-butanediol from glycerol without 1,3-propanediol formation by Raoultella ornithinolytica B6.
abstract: Conversion of crude glycerol derived from biodiesel processes to value-added chemicals has attracted much attention. Herein, Raoultella ornithinolytica B6 was investigated for the high production of 2,3-butanediol (2,3-BD) from glycerol without 1,3-propanediol (1,3-PD) formation, a by-product hindering 2,3-BD purification. By evaluating the effects of temperature, agitation speed, and pH control strategy, the fermentation conditions favoring 2,3-BD production were found to be 25 °C, 400 rpm, and pH control with a lower limit of 5.5, respectively. Notably, significant pH fluctuations which positively affect 2,3-BD production were generated by simply controlling the lower pH limit at 5.5. In fed-batch fermentation under those conditions, R. ornithinolytica B6 produced 2,3-BD up to 79.25 g/L, and further enhancement of 2,3-BD production (89.45 g/L) was achieved by overexpressing homologous 2,3-BD synthesis genes (the budABC). When pretreated crude glycerol was used as a sole carbon source, R. ornithinolytica B6 overexpressing budABC produced 78.10 g/L of 2,3-BD with the yield of 0.42 g/g and the productivity of 0.62 g/L/h. The 2,3-BD titer, yield, and productivity values obtained in this study are the highest 2,3-BD production from glycerol among 1,3-PD synthesis-deficient 2,3-BD producers, demonstrating R. ornithinolytica B6 as a promising 2,3-BD producer from glycerol.
authors.affiliation: Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea.|Interdisciplinary Program in Agricultural Biotechnology, Collage of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea.
authors.forename: Taeyeon
authors.initials: T
authors.lastname: Kim
authors.affiliation: C1 Gas Refinery R&D Center, Sogang University, Seoul, Republic of Korea.
authors.forename: Sukhyeong
authors.initials: S
authors.lastname: Cho
authors.affiliation: Department of Food Science and Biotechnology, Sungkyunkwan University, Suwon, Republic of Korea.
authors.forename: Han Min
authors.initials: HM
authors.lastname: Woo
authors.affiliation: Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea.|Clean Energy and Chemical Engineering, Korea University of Science and Technology, Daejeon, Republic of Korea.
authors.forename: Sun-Mi
authors.initials: SM
authors.lastname: Lee
authors.affiliation: C1 Gas Refinery R&D Center, Sogang University, Seoul, Republic of Korea.|Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, Republic of Korea.
authors.forename: Jinwon
authors.initials: J
authors.lastname: Lee
authors.affiliation: Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea. yum@kist.re.kr.|Clean Energy and Chemical Engineering, Korea University of Science and Technology, Daejeon, Republic of Korea. yum@kist.re.kr.
authors.forename: Youngsoon
authors.identifier: http://orcid.org/0000-0003-1695-1874
authors.initials: Y
authors.lastname: Um
authors.affiliation: Interdisciplinary Program in Agricultural Biotechnology, Collage of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea. jhseo94@snu.ac.kr.|Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea. jhseo94@snu.ac.kr.
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Seo
mesh_terms: D056804:Biofuels; D019149:Bioreactors; D002072:Butylene Glycols / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D004755:Enterobacteriaceae / Q000378:metabolism*; D005285:Fermentation; D005990:Glycerol / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D011409:Propylene Glycols / Q000378:metabolism*; D013696:Temperature
chemical_list: D056804:Biofuels; D002072:Butylene Glycols; D003470:Culture Media; D011409:Propylene Glycols; C026978:2,3-butylene glycol; C041787:1,3-propanediol; D002244:Carbon; D005990:Glycerol
keywords: 2,3-Butanediol; Crude glycerol; Fed-batch fermentation; Raoultella ornithinolytica; budABC