title: Metabolic engineering of Klebsiella pneumoniae based on in silico analysis and its pilot-scale application for 1,3-propanediol and 2,3-butanediol co-production.
abstract: Klebsiella pneumoniae naturally produces relatively large amounts of 1,3-propanediol (1,3-PD) and 2,3-butanediol (2,3-BD) along with various byproducts using glycerol as a carbon source. The ldhA and mdh genes in K. pneumoniae were deleted based on its in silico gene knockout simulation with the criteria of maximizing 1,3-PD and 2,3-BD production and minimizing byproducts formation and cell growth retardation. In addition, the agitation speed, which is known to strongly affect 1,3-PD and 2,3-BD production in Klebsiella strains, was optimized. The K. pneumoniae ΔldhA Δmdh strain produced 125 g/L of diols (1,3-PD and 2,3-BD) with a productivity of 2.0 g/L/h in the lab-scale (5-L bioreactor) fed-batch fermentation using high-quality guaranteed reagent grade glycerol. To evaluate the industrial capacity of the constructed K. pneumoniae ΔldhA Δmdh strain, a pilot-scale (5000-L bioreactor) fed-batch fermentation was carried out using crude glycerol obtained from the industrial biodiesel plant. The pilot-scale fed-batch fermentation of the K. pneumoniae ΔldhA Δmdh strain produced 114 g/L of diols (70 g/L of 1,3-PD and 44 g/L of 2,3-BD), with a yield of 0.60 g diols per gram glycerol and a productivity of 2.2 g/L/h of diols, which should be suitable for the industrial co-production of 1,3-PD and 2,3-BD.
authors.affiliation: Research and Development Center, GS Caltex Corporation, Expo-ro 359, Yuseong-gu, Daejeon, 34122, Republic of Korea.
authors.forename: Jong Myoung
authors.initials: JM
authors.lastname: Park
authors.affiliation: Research and Development Center, GS Caltex Corporation, Expo-ro 359, Yuseong-gu, Daejeon, 34122, Republic of Korea.
authors.forename: Chelladurai
authors.initials: C
authors.lastname: Rathnasingh
authors.affiliation: Research and Development Center, GS Caltex Corporation, Expo-ro 359, Yuseong-gu, Daejeon, 34122, Republic of Korea. hyohaks@gscaltex.com.
authors.forename: Hyohak
authors.initials: H
authors.lastname: Song
mesh_terms: D061249:Batch Cell Culture Techniques; D019149:Bioreactors; D002072:Butylene Glycols / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D005285:Fermentation; D055786:Gene Knockout Techniques; D005990:Glycerol / Q000378:metabolism; D007218:Industrial Microbiology; D007711:Klebsiella pneumoniae / Q000235:genetics* / Q000302:isolation & purification; D060847:Metabolic Engineering; D000074041:Microorganisms, Genetically-Modified; D010865:Pilot Projects; D011409:Propylene Glycols / Q000378:metabolism*
chemical_list: D002072:Butylene Glycols; D003470:Culture Media; D011409:Propylene Glycols; C026978:2,3-butylene glycol; C041787:1,3-propanediol; D005990:Glycerol
keywords: 1,3-Propanediol; 2,3-Butanediol; 5000-L bioreactor; In silico; Klebsiella pneumoniae; Pilot-scale fermentation