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Metabolic pathway engineering for production of 1,2-propanediol and 1-propanol by Corynebacterium glutamicum.

Siebert D, Wendisch VF - Biotechnol Biofuels (2015)

Bottom Line: To construct a 1-propanol producer, the operon ppdABC from Klebsiella oxytoca encoding diol dehydratase was expressed in the improved 1,2-propanediol producing strain ending up with 12 mM 1-propanol and up to 60 mM unconverted 1,2-propanediol.Production of 1,2-propanediol by C. glutamicum was improved by metabolic engineering targeting endogenous enzymes.Furthermore, to the best of our knowledge, production of 1-propanol by recombinant C. glutamicum was demonstrated for the first time.

View Article: PubMed Central - PubMed

Affiliation: Chair of Genetics of Prokaryotes, Faculty of Biology and CeBiTec, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.

ABSTRACT

Background: Production of the versatile bulk chemical 1,2-propanediol and the potential biofuel 1-propanol is still dependent on petroleum, but some approaches to establish bio-based production from renewable feed stocks and to avoid toxic intermediates have been described. The biotechnological workhorse Corynebacterium glutamicum has also been shown to be able to overproduce 1,2-propanediol by metabolic engineering. Additionally, C. glutamicum has previously been engineered for production of the biofuels ethanol and isobutanol but not for 1-propanol.

Results: In this study, the improved production of 1,2-propanediol by C. glutamicum is presented. The product yield of a C. glutamicum strain expressing the heterologous genes gldA and mgsA from Escherichia coli that encode methylglyoxal synthase gene and glycerol dehydrogenase, respectively, was improved by additional expression of alcohol dehydrogenase gene yqhD from E. coli leading to a yield of 0.131 mol/mol glucose. Deletion of the endogenous genes hdpA and ldh encoding dihydroxyacetone phosphate phosphatase and lactate dehydrogenase, respectively, prevented formation of glycerol and lactate as by-products and improved the yield to 0.343 mol/mol glucose. To construct a 1-propanol producer, the operon ppdABC from Klebsiella oxytoca encoding diol dehydratase was expressed in the improved 1,2-propanediol producing strain ending up with 12 mM 1-propanol and up to 60 mM unconverted 1,2-propanediol. Thus, B12-dependent diol dehydratase activity may be limiting 1-propanol production.

Conclusions: Production of 1,2-propanediol by C. glutamicum was improved by metabolic engineering targeting endogenous enzymes. Furthermore, to the best of our knowledge, production of 1-propanol by recombinant C. glutamicum was demonstrated for the first time.

No MeSH data available.


Related in: MedlinePlus

Influence of YqhD from E. coli on 1,2-propanediol production by recombinant C. glutamicum strains. Batch cultivation of C. glutamicum strains WT(pEKEx3) (circles, dashed lines), WT(pEKEx3-mgsA-gldA) (triangles, solid lines), and WT(pEKEx3-mgsA-yqhD-gldA) (squares, solid lines) were performed, and a optical density at 600 nm (solid symbols) and glucose concentration (open symbols), b 1,2-propanediol (solid symbols) and acetol (open symbols) concentrations, and c glycerol (solid symbols) and DHA (open symbols) concentrations are shown. Means and standard errors of three independent cultivations are shown
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Fig2: Influence of YqhD from E. coli on 1,2-propanediol production by recombinant C. glutamicum strains. Batch cultivation of C. glutamicum strains WT(pEKEx3) (circles, dashed lines), WT(pEKEx3-mgsA-gldA) (triangles, solid lines), and WT(pEKEx3-mgsA-yqhD-gldA) (squares, solid lines) were performed, and a optical density at 600 nm (solid symbols) and glucose concentration (open symbols), b 1,2-propanediol (solid symbols) and acetol (open symbols) concentrations, and c glycerol (solid symbols) and DHA (open symbols) concentrations are shown. Means and standard errors of three independent cultivations are shown

Mentions: C. glutamicum has previously been engineered for 1,2-propanediol production by expressing the heterologous genes mgsA and gldA encoding methylglyoxal synthase gene and glycerol dehydrogenase from E. coli [12]. Expression of these genes as artificial operon from the plasmid pEKEx3-mgsA-gldA in C. glutamicum WT yielded 19 ± 1 mM 1,2-propanediol within 51 h (Fig. 2) when using modified CGXII minimal medium with a decreased nitrogen content (5 g/L ammonium sulfate) and 184 ± 1 mM glucose as sole carbon source. Thus, the base strain produced 1,2-propanediol with a yield of 0.103 mol/mol glucose.


Metabolic pathway engineering for production of 1,2-propanediol and 1-propanol by Corynebacterium glutamicum.

Siebert D, Wendisch VF - Biotechnol Biofuels (2015)

Influence of YqhD from E. coli on 1,2-propanediol production by recombinant C. glutamicum strains. Batch cultivation of C. glutamicum strains WT(pEKEx3) (circles, dashed lines), WT(pEKEx3-mgsA-gldA) (triangles, solid lines), and WT(pEKEx3-mgsA-yqhD-gldA) (squares, solid lines) were performed, and a optical density at 600 nm (solid symbols) and glucose concentration (open symbols), b 1,2-propanediol (solid symbols) and acetol (open symbols) concentrations, and c glycerol (solid symbols) and DHA (open symbols) concentrations are shown. Means and standard errors of three independent cultivations are shown
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4478622&req=5

Fig2: Influence of YqhD from E. coli on 1,2-propanediol production by recombinant C. glutamicum strains. Batch cultivation of C. glutamicum strains WT(pEKEx3) (circles, dashed lines), WT(pEKEx3-mgsA-gldA) (triangles, solid lines), and WT(pEKEx3-mgsA-yqhD-gldA) (squares, solid lines) were performed, and a optical density at 600 nm (solid symbols) and glucose concentration (open symbols), b 1,2-propanediol (solid symbols) and acetol (open symbols) concentrations, and c glycerol (solid symbols) and DHA (open symbols) concentrations are shown. Means and standard errors of three independent cultivations are shown
Mentions: C. glutamicum has previously been engineered for 1,2-propanediol production by expressing the heterologous genes mgsA and gldA encoding methylglyoxal synthase gene and glycerol dehydrogenase from E. coli [12]. Expression of these genes as artificial operon from the plasmid pEKEx3-mgsA-gldA in C. glutamicum WT yielded 19 ± 1 mM 1,2-propanediol within 51 h (Fig. 2) when using modified CGXII minimal medium with a decreased nitrogen content (5 g/L ammonium sulfate) and 184 ± 1 mM glucose as sole carbon source. Thus, the base strain produced 1,2-propanediol with a yield of 0.103 mol/mol glucose.

Bottom Line: To construct a 1-propanol producer, the operon ppdABC from Klebsiella oxytoca encoding diol dehydratase was expressed in the improved 1,2-propanediol producing strain ending up with 12 mM 1-propanol and up to 60 mM unconverted 1,2-propanediol.Production of 1,2-propanediol by C. glutamicum was improved by metabolic engineering targeting endogenous enzymes.Furthermore, to the best of our knowledge, production of 1-propanol by recombinant C. glutamicum was demonstrated for the first time.

View Article: PubMed Central - PubMed

Affiliation: Chair of Genetics of Prokaryotes, Faculty of Biology and CeBiTec, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.

ABSTRACT

Background: Production of the versatile bulk chemical 1,2-propanediol and the potential biofuel 1-propanol is still dependent on petroleum, but some approaches to establish bio-based production from renewable feed stocks and to avoid toxic intermediates have been described. The biotechnological workhorse Corynebacterium glutamicum has also been shown to be able to overproduce 1,2-propanediol by metabolic engineering. Additionally, C. glutamicum has previously been engineered for production of the biofuels ethanol and isobutanol but not for 1-propanol.

Results: In this study, the improved production of 1,2-propanediol by C. glutamicum is presented. The product yield of a C. glutamicum strain expressing the heterologous genes gldA and mgsA from Escherichia coli that encode methylglyoxal synthase gene and glycerol dehydrogenase, respectively, was improved by additional expression of alcohol dehydrogenase gene yqhD from E. coli leading to a yield of 0.131 mol/mol glucose. Deletion of the endogenous genes hdpA and ldh encoding dihydroxyacetone phosphate phosphatase and lactate dehydrogenase, respectively, prevented formation of glycerol and lactate as by-products and improved the yield to 0.343 mol/mol glucose. To construct a 1-propanol producer, the operon ppdABC from Klebsiella oxytoca encoding diol dehydratase was expressed in the improved 1,2-propanediol producing strain ending up with 12 mM 1-propanol and up to 60 mM unconverted 1,2-propanediol. Thus, B12-dependent diol dehydratase activity may be limiting 1-propanol production.

Conclusions: Production of 1,2-propanediol by C. glutamicum was improved by metabolic engineering targeting endogenous enzymes. Furthermore, to the best of our knowledge, production of 1-propanol by recombinant C. glutamicum was demonstrated for the first time.

No MeSH data available.


Related in: MedlinePlus