title: Optimization of culture conditions for 1,3-propanediol production from glycerol using a mutant strain of Klebsiella pneumoniae.
abstract: In the present work, mutant strains of Klebsiella pneumoniae with deletions of the als gene encoding acetolactate synthase involved in synthesis of 2,3-butanediol, the ldhA gene encoding lactate dehydrogenase required for lactate synthesis, or both genes, were prepared. Production of 1,3-propanediol (1,3-PD) from glycerol was enhanced in the ldhA mutant strain (ΔldhA), but lower in Δals or Δals ΔldhA mutant strains compared to the parent strain, concomitant with a reduction in the glycerol consumption rate, indicating that deletion of ldhA alone was useful to improve 1,3-PD production. Fed-batch fermentation analysis revealed that, in the ΔldhA mutant strain, 1,3-PD production was higher at low pH than at neutral pH; the reverse was true for the parent strain. Further optimization of culture conditions, by variation of aeration and glycerol feed rates, dramatically improved the production of 1,3-PD by the mutant strain. The maximum level attained was 102.7 g l(-1) of 1,3-PD from glycerol.
authors.affiliation: Microbe-based Fusion Technology Research Center, Jeonbuk Branch Institute, Korea Research Institute of Bioscience and Biotechnology, Jeongeup, Jeonbuk, South Korea.
authors.forename: Baek-Rock
authors.initials: BR
authors.lastname: Oh
authors.forename: Jeong-Woo
authors.initials: JW
authors.lastname: Seo
authors.forename: Sun-Yeon
authors.initials: SY
authors.lastname: Heo
authors.forename: Won-Kyung
authors.initials: WK
authors.lastname: Hong
authors.forename: Lian Hua
authors.initials: LH
authors.lastname: Luo
authors.forename: Seonghun
authors.initials: S
authors.lastname: Kim
authors.forename: Don-Hee
authors.initials: DH
authors.lastname: Park
authors.forename: Chul Ho
authors.initials: CH
authors.lastname: Kim
mesh_terms: D000095:Acetolactate Synthase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D061249:Batch Cell Culture Techniques; D002072:Butylene Glycols / Q000737:chemistry; D005285:Fermentation; D005990:Glycerol / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D007770:L-Lactate Dehydrogenase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D011409:Propylene Glycols / Q000737:chemistry*
chemical_list: D002072:Butylene Glycols; D011409:Propylene Glycols; C026978:2,3-butylene glycol; C041787:1,3-propanediol; D007770:L-Lactate Dehydrogenase; D000095:Acetolactate Synthase; D005990:Glycerol