title: Deletion of ldhA and aldH genes in Klebsiella pneumoniae to enhance 1,3-propanediol production.
abstract: OBJECTIVE
  To improve 1,3-propanediol (1,3-PD) production and reduce byproduct concentration during the fermentation of Klebsiella pneumonia.
  
  
  RESULTS
  Klebsiella. pneumonia 2-1ΔldhA, K. pneumonia 2-1ΔaldH and K. pneumonia 2-1ΔldhAΔaldH mutant strains were obtained through deletion of the ldhA gene encoding lactate dehydrogenase required for lactate synthesis and the aldH gene encoding acetaldehyde dehydrogenase involved in the synthesis of ethanol. After fed-batch fermentation, the production of 1,3-PD from glycerol was enhanced and the concentrations of byproducts were reduced compared with the original strain K. pneumonia 2-1. The maximum yields of 1,3-PD were 85.7, 82.5 and 87.5 g/l in the respective mutant strains.
  
  
  CONCLUSIONS
  Deletion of either aldH or ldhA promoted 1,3-PD production in K. pneumonia.
authors.affiliation: Shandong Provincial Key Laboratory of Microbial Engineering, College of Biological Engineering, Qilu University of Technology, Jinan, 250353, China.
authors.forename: Lifei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Shandong Provincial Key Laboratory of Microbial Engineering, College of Biological Engineering, Qilu University of Technology, Jinan, 250353, China. machunling20022@163.com.
authors.forename: Chunling
authors.initials: C
authors.lastname: Ma
authors.affiliation: Shandong Provincial Key Laboratory of Microbial Engineering, College of Biological Engineering, Qilu University of Technology, Jinan, 250353, China.
authors.forename: Ruiming
authors.initials: R
authors.lastname: Wang
authors.affiliation: Shandong Provincial Key Laboratory of Microbial Engineering, College of Biological Engineering, Qilu University of Technology, Jinan, 250353, China.
authors.forename: Jianlou
authors.initials: J
authors.lastname: Yang
authors.affiliation: Shandong Provincial Key Laboratory of Microbial Engineering, College of Biological Engineering, Qilu University of Technology, Jinan, 250353, China.
authors.forename: Haijie
authors.initials: H
authors.lastname: Zheng
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics; D061249:Batch Cell Culture Techniques; D005285:Fermentation; D017353:Gene Deletion; D005818:Genetic Engineering / Q000379:methods; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000235:genetics; D007770:L-Lactate Dehydrogenase / Q000235:genetics*; D011409:Propylene Glycols / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D011409:Propylene Glycols; C041787:1,3-propanediol; D007770:L-Lactate Dehydrogenase; D000445:Aldehyde Oxidoreductases; C018699:aldehyde dehydrogenase (NAD(P)+)
keywords: 1,3-Propanediol; Acetaldehyde dehydrogenase; Gene deletion; Klebsiella pneumonia; Lactate dehydrogenase; λRed recombination