Figure 1.
Major metabolic pathways in K. pneumoniae that produce byproducts, including 2,3-BDO.
Gray arrows and bold arrows indicate carbon flux and enhanced metabolic pathways due to budA and budB gene overexpression, respectively.
Table 1.
Bacterial strains and plasmids used in this study.
Table 2.
Primers used in real-time PCR.
Figure 2.
Batch fermentation profiles of metabolites in K. pneumoniae mutant strains: (A) SGSB100, (B) SGSB103, (C) SGSB104, and (D) SGSB105.
Closed squares = glucose; closed stars = cell growth; closed triangles = 2,3-BDO; closed circles = lactate; open squares = ethanol; open triangles = acetate; open circles = succinate.
Table 3.
The distribution of glucose by K, pneumoniae SGSB100, SGSB103, SGSB104 and SGSB105 in batch fermentation at 12hr (carbon conversion ratio (%)).
Figure 3.
Real-time PCR results for (A) ldhA, (B) budA, (C) budB, and (D) budC genes of K. pneumoniae strains SGSB100, SGSB103, SGSB104, and SGSB105 at 3 h (black filling) and at 12 h (herringbone filling) of batch fermentation.
The abscissa and ordinate represent strains and expression levels of each gene, respectively. X = relative quantity (second derivative maximum) based on the value for the 16srRNA gene.
Figure 4.
Fed-batch fermentation profile of K. pneumoniae strain SGSB105.
Closed squares = glucose; closed stars = cell growth; closed triangles = 2,3-BDO; closed diamonds = acetoin; closed circles = lactate; open squares = ethanol; open triangles = acetate; open circles = succinate.