Limits...
Overexpression of a modified 6-phosphofructo-1-kinase results in an increased itaconic acid productivity in Aspergillus niger.

van der Straat L, Tamayo-Ramos JA, Schonewille T, de Graaff LH - AMB Express (2013)

Bottom Line: The combined expression of pfkA with the itaconic acid biosynthetic cluster resulted in significantly increased itaconic acid production at earlier time points.Also the itaconic acid productivity increased significantly.The maximum itaconic acid productivity that was reached under these conditions was 0.15 g/L/h, which is only a factor 17 lower than the 2.5 g/L/h that according to the US Department of Energy should be achieved to have an economically feasible production process.

View Article: PubMed Central - HTML - PubMed

Affiliation: Microbial Systems Biology, Laboratory of Systems and Synthetic Biology, Wageningen University, Dreijenplein 10, 6703, HB, Wageningen, Netherlands. leo.degraaff@wur.nl.

ABSTRACT
A modified 6-phosphofructo-1-kinase was expressed in a citrate producing Aspergillus niger strain in combination with cis-aconitate decarboxylase from Aspergillus terreus to study the effect on the production of itaconic acid. The modified pfkA gene was also expressed in combination with the itaconic acid biosynthetic cluster from A. terreus, which consists of cis-aconitate decarboxylase cadA, a putative mitochondrial transporter mttA and a putative plasmamembrane transporter mfsA. The combined expression of pfkA and cadA resulted in increased citrate levels, but did not show increased itaconic acid levels. The combined expression of pfkA with the itaconic acid biosynthetic cluster resulted in significantly increased itaconic acid production at earlier time points. Also the itaconic acid productivity increased significantly. The maximum itaconic acid productivity that was reached under these conditions was 0.15 g/L/h, which is only a factor 17 lower than the 2.5 g/L/h that according to the US Department of Energy should be achieved to have an economically feasible production process.

No MeSH data available.


Related in: MedlinePlus

The average total acid production in C-mmol/L/h for the transformants harboring the cluster genes cadA, mttA, mfsA and the modified pfkA (T Av) compared to the average productivity of the transformants harboring only the cluster genes cadA, mttA, mfsA (C Av). At time points t=30h the difference in productivity is significantly different (T-Test, p=0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4016035&req=5

Figure 8: The average total acid production in C-mmol/L/h for the transformants harboring the cluster genes cadA, mttA, mfsA and the modified pfkA (T Av) compared to the average productivity of the transformants harboring only the cluster genes cadA, mttA, mfsA (C Av). At time points t=30h the difference in productivity is significantly different (T-Test, p=0.01).

Mentions: The highest itaconic acid productivity level within the modified pfkA recombinant strains (T series) was reached 78 hours after induction by one single transformant (147 mg/L/h), while, on average, the highest productivity levels for this group of strains was already reached after 30 hours (102 mg/L/h) (FigureĀ 7). The total organic acid productivity, expressed in C-mmol/L/h (Figure 8), increased significantly at t=30 h (p = 0.01) for the transformants (T series) compared to the strains harboring only the cluster genes (C series). The maximum total organic acid productivity at t=30 h was 6.25 C-mmol/L/h and corresponded to one of the transformants harboring the cluster genes and the modified pfkA gene, while the best producing strain, expressing only itaconic acid biosynthetic cluster, achieved a maximum of 3.9 C-mmol/L/h.


Overexpression of a modified 6-phosphofructo-1-kinase results in an increased itaconic acid productivity in Aspergillus niger.

van der Straat L, Tamayo-Ramos JA, Schonewille T, de Graaff LH - AMB Express (2013)

The average total acid production in C-mmol/L/h for the transformants harboring the cluster genes cadA, mttA, mfsA and the modified pfkA (T Av) compared to the average productivity of the transformants harboring only the cluster genes cadA, mttA, mfsA (C Av). At time points t=30h the difference in productivity is significantly different (T-Test, p=0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4016035&req=5

Figure 8: The average total acid production in C-mmol/L/h for the transformants harboring the cluster genes cadA, mttA, mfsA and the modified pfkA (T Av) compared to the average productivity of the transformants harboring only the cluster genes cadA, mttA, mfsA (C Av). At time points t=30h the difference in productivity is significantly different (T-Test, p=0.01).
Mentions: The highest itaconic acid productivity level within the modified pfkA recombinant strains (T series) was reached 78 hours after induction by one single transformant (147 mg/L/h), while, on average, the highest productivity levels for this group of strains was already reached after 30 hours (102 mg/L/h) (FigureĀ 7). The total organic acid productivity, expressed in C-mmol/L/h (Figure 8), increased significantly at t=30 h (p = 0.01) for the transformants (T series) compared to the strains harboring only the cluster genes (C series). The maximum total organic acid productivity at t=30 h was 6.25 C-mmol/L/h and corresponded to one of the transformants harboring the cluster genes and the modified pfkA gene, while the best producing strain, expressing only itaconic acid biosynthetic cluster, achieved a maximum of 3.9 C-mmol/L/h.

Bottom Line: The combined expression of pfkA with the itaconic acid biosynthetic cluster resulted in significantly increased itaconic acid production at earlier time points.Also the itaconic acid productivity increased significantly.The maximum itaconic acid productivity that was reached under these conditions was 0.15 g/L/h, which is only a factor 17 lower than the 2.5 g/L/h that according to the US Department of Energy should be achieved to have an economically feasible production process.

View Article: PubMed Central - HTML - PubMed

Affiliation: Microbial Systems Biology, Laboratory of Systems and Synthetic Biology, Wageningen University, Dreijenplein 10, 6703, HB, Wageningen, Netherlands. leo.degraaff@wur.nl.

ABSTRACT
A modified 6-phosphofructo-1-kinase was expressed in a citrate producing Aspergillus niger strain in combination with cis-aconitate decarboxylase from Aspergillus terreus to study the effect on the production of itaconic acid. The modified pfkA gene was also expressed in combination with the itaconic acid biosynthetic cluster from A. terreus, which consists of cis-aconitate decarboxylase cadA, a putative mitochondrial transporter mttA and a putative plasmamembrane transporter mfsA. The combined expression of pfkA and cadA resulted in increased citrate levels, but did not show increased itaconic acid levels. The combined expression of pfkA with the itaconic acid biosynthetic cluster resulted in significantly increased itaconic acid production at earlier time points. Also the itaconic acid productivity increased significantly. The maximum itaconic acid productivity that was reached under these conditions was 0.15 g/L/h, which is only a factor 17 lower than the 2.5 g/L/h that according to the US Department of Energy should be achieved to have an economically feasible production process.

No MeSH data available.


Related in: MedlinePlus