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Two-dimensional isobutyl acetate production pathways to improve carbon yield.

Tashiro Y, Desai SH, Atsumi S - Nat Commun (2015)

Bottom Line: To avoid these problems, we describe here the construction of a metabolic pathway that simultaneously utilizes glucose and acetate.We demonstrate the utility of this approach for isobutyl acetate (IBA) production, wherein IBA production with glucose and acetate achieves a higher carbon yield than with either sole carbon source.These results highlight the potential for this multiple carbon source approach to improve the TMCY and balance redox in biosynthetic pathways.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, USA.

ABSTRACT
For an economically competitive biological process, achieving high carbon yield of a target chemical is crucial. In biochemical production, pyruvate and acetyl-CoA are primary building blocks. When sugar is used as the sole biosynthetic substrate, acetyl-CoA is commonly generated by pyruvate decarboxylation. However, pyruvate decarboxylation during acetyl-CoA formation limits the theoretical maximum carbon yield (TMCY) by releasing carbon, and in some cases also leads to redox imbalance. To avoid these problems, we describe here the construction of a metabolic pathway that simultaneously utilizes glucose and acetate. Acetate is utilized to produce acetyl-CoA without carbon loss or redox imbalance. We demonstrate the utility of this approach for isobutyl acetate (IBA) production, wherein IBA production with glucose and acetate achieves a higher carbon yield than with either sole carbon source. These results highlight the potential for this multiple carbon source approach to improve the TMCY and balance redox in biosynthetic pathways.

No MeSH data available.


Related in: MedlinePlus

Acetate-assimilating pathway construction.(a) Three different acetate-assimilating pathways were constructed in JCL260 (strains 1 (diamond), 2 (square), 3 (triangle) or 4 (circle); Table 1) and screened in M9 minimal media with 10 g l−1 acetate as a sole carbon source; NC represents negative control using strain 4. Growth of JCL260 (b) and AL2045 (c) on acetate and glucose. The right panel shows growth of strains 1 (b) and 5 (c) while the left panel depicts growth of strains 4 (b) and 6 (c) Error bars indicate s.d. (n=3).
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f2: Acetate-assimilating pathway construction.(a) Three different acetate-assimilating pathways were constructed in JCL260 (strains 1 (diamond), 2 (square), 3 (triangle) or 4 (circle); Table 1) and screened in M9 minimal media with 10 g l−1 acetate as a sole carbon source; NC represents negative control using strain 4. Growth of JCL260 (b) and AL2045 (c) on acetate and glucose. The right panel shows growth of strains 1 (b) and 5 (c) while the left panel depicts growth of strains 4 (b) and 6 (c) Error bars indicate s.d. (n=3).

Mentions: Three acetate-assimilating pathways were constructed (Fig. 1b). In the acetate kinase–phosphotransacetylase (AckA–Pta) pathway31, acetate is phosphorylated by AckA using ATP to produce acetyl phosphate, which is then converted into acetyl-CoA by Pta. The acetyl-CoA synthetase (Acs) pathway consists of just one enzyme: Acs, which requires ATP and proceeds through acetyladenylate as an intermediate31. Last is the AldB–MhpF pathway3233, which potentially could help improve TMCY because this pathway does not utilize ATP. Both AldB and MhpF are known as acetaldehyde dehydrogenase, but MhpF is CoA-dependent. To identify which pathway would allow the most acetate consumption, genes for the different acetate-assimilating pathways were individually introduced in JCL260 (strains 1, 2 and 3, respectively, Table 1) and the growth of the strains was compared with 10 g l−1 glucose or 10 g l−1 acetate as a sole carbon source in micro-aerobic conditions (Fig. 2a).


Two-dimensional isobutyl acetate production pathways to improve carbon yield.

Tashiro Y, Desai SH, Atsumi S - Nat Commun (2015)

Acetate-assimilating pathway construction.(a) Three different acetate-assimilating pathways were constructed in JCL260 (strains 1 (diamond), 2 (square), 3 (triangle) or 4 (circle); Table 1) and screened in M9 minimal media with 10 g l−1 acetate as a sole carbon source; NC represents negative control using strain 4. Growth of JCL260 (b) and AL2045 (c) on acetate and glucose. The right panel shows growth of strains 1 (b) and 5 (c) while the left panel depicts growth of strains 4 (b) and 6 (c) Error bars indicate s.d. (n=3).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4491173&req=5

f2: Acetate-assimilating pathway construction.(a) Three different acetate-assimilating pathways were constructed in JCL260 (strains 1 (diamond), 2 (square), 3 (triangle) or 4 (circle); Table 1) and screened in M9 minimal media with 10 g l−1 acetate as a sole carbon source; NC represents negative control using strain 4. Growth of JCL260 (b) and AL2045 (c) on acetate and glucose. The right panel shows growth of strains 1 (b) and 5 (c) while the left panel depicts growth of strains 4 (b) and 6 (c) Error bars indicate s.d. (n=3).
Mentions: Three acetate-assimilating pathways were constructed (Fig. 1b). In the acetate kinase–phosphotransacetylase (AckA–Pta) pathway31, acetate is phosphorylated by AckA using ATP to produce acetyl phosphate, which is then converted into acetyl-CoA by Pta. The acetyl-CoA synthetase (Acs) pathway consists of just one enzyme: Acs, which requires ATP and proceeds through acetyladenylate as an intermediate31. Last is the AldB–MhpF pathway3233, which potentially could help improve TMCY because this pathway does not utilize ATP. Both AldB and MhpF are known as acetaldehyde dehydrogenase, but MhpF is CoA-dependent. To identify which pathway would allow the most acetate consumption, genes for the different acetate-assimilating pathways were individually introduced in JCL260 (strains 1, 2 and 3, respectively, Table 1) and the growth of the strains was compared with 10 g l−1 glucose or 10 g l−1 acetate as a sole carbon source in micro-aerobic conditions (Fig. 2a).

Bottom Line: To avoid these problems, we describe here the construction of a metabolic pathway that simultaneously utilizes glucose and acetate.We demonstrate the utility of this approach for isobutyl acetate (IBA) production, wherein IBA production with glucose and acetate achieves a higher carbon yield than with either sole carbon source.These results highlight the potential for this multiple carbon source approach to improve the TMCY and balance redox in biosynthetic pathways.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, USA.

ABSTRACT
For an economically competitive biological process, achieving high carbon yield of a target chemical is crucial. In biochemical production, pyruvate and acetyl-CoA are primary building blocks. When sugar is used as the sole biosynthetic substrate, acetyl-CoA is commonly generated by pyruvate decarboxylation. However, pyruvate decarboxylation during acetyl-CoA formation limits the theoretical maximum carbon yield (TMCY) by releasing carbon, and in some cases also leads to redox imbalance. To avoid these problems, we describe here the construction of a metabolic pathway that simultaneously utilizes glucose and acetate. Acetate is utilized to produce acetyl-CoA without carbon loss or redox imbalance. We demonstrate the utility of this approach for isobutyl acetate (IBA) production, wherein IBA production with glucose and acetate achieves a higher carbon yield than with either sole carbon source. These results highlight the potential for this multiple carbon source approach to improve the TMCY and balance redox in biosynthetic pathways.

No MeSH data available.


Related in: MedlinePlus