関: Cupriavidus necator、Ralstonia eutropha

English Journal

Improvement on the yield of polyhydroxyalkanotes production from cheese whey by a recombinant Escherichia coli strain using the proton suicide methodology.

Pais J1, Farinha I1, Freitas F1, Serafim LS2, Martínez V3, Martínez JC4, Arévalo-Rodríguez M4, Auxiliadora Prieto M3, Reis MA5.Author information 1REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.2CICECO, Departamento de Química, Universidade de Aveiro, Campus Universitário de Santiago, P-3810-193 Aveiro, Portugal.3Environmental Biology Department, Centro de Investigaciones Biológicas, CSIC, C/Ramiro de Maeztu, 9, 28040 Madrid, Spain.4Biomedal S.L., Avda. Américo Vespucio 5E. 1ª M12, 41092 Seville, Spain.5REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, 2829-516 Caparica, Portugal. Electronic address: amr@fct.unl.pt.AbstractIn this work Escherichia coli strain CML3-1 was engineered through the insertion of Cupriavidus necator P(3HB)-synthesis genes, fused to a lactose-inducible promoter, into the chromosome, via transposition-mediated mechanism. It was shown that polyhydroxyalkanotes (PHAs) production by this strain, using cheese whey, was low due to a significant organic acids (OA) synthesis. The proton suicide method was used as a strategy to obtain an E. coli mutant strain with a reduced OA-producing capacity, aiming at driving bacterial metabolism toward PHAs synthesis. Thirteen E. coli mutant strains were obtained and tested in shake flask assays, using either rich or defined media supplemented with lactose. P8-X8 was selected as the best candidate strain for bioreactor fed-batch tests using cheese whey as the sole carbon source. Although cell growth was considerably slower for this mutant strain, a lower yield of OA on substrate (0.04CmolOA/Cmollac) and a higher P(3HB) production (18.88gP(3HB)/L) were achieved, comparing to the original recombinant strain (0.11CmolOA/Cmollac and 7.8gP(3HB)/L, respectively). This methodology showed to be effective on the reduction of OA yield by consequently improving the P(3HB) yield on lactose (0.28CmolP(3HB)/Cmollac vs 0.10CmolP(3HB)/Cmollac of the original strain).
Enzyme and microbial technology.Enzyme Microb Technol.2014 Feb 5;55:151-8. doi: 10.1016/j.enzmictec.2013.11.004. Epub 2013 Nov 21.
In this work Escherichia coli strain CML3-1 was engineered through the insertion of Cupriavidus necator P(3HB)-synthesis genes, fused to a lactose-inducible promoter, into the chromosome, via transposition-mediated mechanism. It was shown that polyhydroxyalkanotes (PHAs) production by this strain, u
PMID 24411458

Production of green biodegradable plastics of poly(3-hydroxybutyrate) from renewable resources of agricultural residues.

Dahman Y, Ugwu CU.Author information Department of Chemical Engineering, Ryerson University, Toronto, ON, M5B 2K3, Canada, ydahman@ryerson.ca.AbstractThis work describes potential opportunities for utilization of agro-industrial residues to produce green biodegradable plastics of poly(3-hydroxybutyrate) (PHB). Wheat straws were examined with good efficacy of carbon substrates using Cupriavidus necator. Production was examined in separate hydrolysis and fermentation (SHF) in the presence and absence of WS hydrolysis enzymes, and in simultaneous saccharification and fermentation (SSF) with enzymes. Results showed that production of PHB in SSF was more efficient in terms of viable cell count, cell dry weight, and PHB production and yield compared to those of SHF and glucose-control cultures. While glucose control experiment produced 4.6 g/L PHB; SSF produced 10.0 g/L compared to 7.1 g/L in SHF when utilizing enzymes during WS hydrolysis. Results showed that most of sugars produced during the hydrolysis were consumed in SHF (~98 %) compared to 89.2 % in SSF. Results also demonstrated that a combination of glucose and xylose can compensate for the excess carbon required for enhancing PHB production by C. necator. However, higher concentration of sugars at the beginning of fermentation in SHF can lead to cell inhibition and consequently catabolite repressions. Accordingly, results demonstrated that the gradual release of sugars in SSF enhanced PHB production. Moreover, the presence of sugars other than glucose and xylose can eliminate PHB degradation in medium of low carbon substrate concentrations in SSF.
Bioprocess and biosystems engineering.Bioprocess Biosyst Eng.2014 Feb 4. [Epub ahead of print]
This work describes potential opportunities for utilization of agro-industrial residues to produce green biodegradable plastics of poly(3-hydroxybutyrate) (PHB). Wheat straws were examined with good efficacy of carbon substrates using Cupriavidus necator. Production was examined in separate hydrolys
PMID 24492886

Phosphorus limitation strategy to increase propionic acid flux towards 3-hydroxyvaleric acid monomers in Cupriavidus necator.

Grousseau E1, Blanchet E2, Déléris S3, Albuquerque MG4, Paul E5, Uribelarrea JL6.Author information 1Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; CNRS, UMR5504, F-31400 Toulouse, France; VEOLIA Environnement, Centre de Recherche sur l'Eau, Chemin de la Digue, BP 76, F-78603 Maisons-Laffitte Cedex, France. Electronic address: estelle.grousseau@insa-toulouse.fr.2Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; CNRS, UMR5504, F-31400 Toulouse, France; VEOLIA Environnement, Centre de Recherche sur l'Eau, Chemin de la Digue, BP 76, F-78603 Maisons-Laffitte Cedex, France. Electronic address: blanchet.elise@gmail.com.3VEOLIA Environnement, Centre de Recherche sur l'Eau, Chemin de la Digue, BP 76, F-78603 Maisons-Laffitte Cedex, France. Electronic address: stephane.deleris@veoliaeau.fr.4VEOLIA Environnement, Centre de Recherche sur l'Eau, Chemin de la Digue, BP 76, F-78603 Maisons-Laffitte Cedex, France. Electronic address: Maria.ALBUQUERQUE@veolia.com.5Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; CNRS, UMR5504, F-31400 Toulouse, France. Electronic address: etienne.paul@insa-toulouse.fr.6Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; CNRS, UMR5504, F-31400 Toulouse, France. Electronic address: uribelarrea@insa-toulouse.fr.AbstractProperties of polyhydroxybutyrate-co-hydroxyvalerate (P(3HB-co-3HV)) depend on their 3HV content. 3HV can be produced by Cupriavidus necator from propionic acid. Few studies explored carbon distribution and dynamics of 3HV and 3HB monomers production, and none of them have been done with phosphorus as limiting nutrient. In this study, fed-batch cultures of C. necator with propionic acid, as sole carbon source or mixed with butyric acid, were performed. Phosphorus deficiency allowed sustaining 3HV production rate and decreasing 3HB production rate, leading to an instant production of up to 100% of 3HV. When a residual growth is sustained by a phosphorus feeding, the maximum 3HV percentage produced from propionic acid is limited to 33% (Mole.Mole(-1)). The association of a second carbon source like butyric acid lead to higher conversion of propionic acid into 3HV. This study showed the importance of the limiting nutrient and of the culture strategy to get the appropriate product.
Bioresource technology.Bioresour Technol.2014 Feb;153:206-15. doi: 10.1016/j.biortech.2013.11.072. Epub 2013 Dec 1.
Properties of polyhydroxybutyrate-co-hydroxyvalerate (P(3HB-co-3HV)) depend on their 3HV content. 3HV can be produced by Cupriavidus necator from propionic acid. Few studies explored carbon distribution and dynamics of 3HV and 3HB monomers production, and none of them have been done with phosphorus
PMID 24365742