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.

Recent developments in the microbial production of 1,3-propanediol

“…It was suggested that the enhancement of NADH/NAD + ratio (increased by 50%) might be the dominant reason for the change of final metabolites concentrations. Oh et al also observed PDO production enhancement in the lactate-deficient K. pneumoniae [70]. In fed-batch fermentation, the maximum concentration of PDO of the mutant was improved from 56.9 to 102.7 g l -1 , compared with the wild type strain.…”

Erratum to: Production of isobutanol from crude glycerol by a genetically-engineered Klebsiella pneumoniae strain

“…The mobile phase was 5 mM H 2 SO 4 at 0.8 ml min -1 . Column and cell were at 65°C and 45°C, respectively (Oh et al 2012a). Isobutanol was determined using GC equipped with a ZB-WAX plus column (Phenomenex).…”

“…Klebsiella pneumoniae DldhA mutant, derived from ATCC 200721, has been described (Oh et al 2012a). Escherichia coli DH5a was used for DNA manipulation.…”

Genetically Engineered Strains: Application and Advances for 1,3-Propanediol Production from Glycerol

“…Some other research groups (40-42) also paid attention to the deletion of both ldhA gene and genes associated with 2,3-BD, such as als gene encoding acetolactate synthase in the biosynthesis of 2,3-BD. Oh et al (44) focused on the mutants of K. pneumoniae with deletions of the als and ldhA genes. However, when using the mutants for producing 1,3-PD in the fed-batch fermentation, only the ∆ldhA strain was able to produce the maximum 1,3-PD (102.7 g/L).…”