Characterisation of the native β-alanine pathway in Cupriavidus necator H16: an attractive route towards 3-hydroxypropionic acid production.
The sustainable production of chemicals and fuels through microbial fermentation will play a pivotal role in reducing our dependence on fossil resources as well as decreasing global emissions of greenhouse gases, and in particular CO2. A particularly promising strategy is to produce the requisite mo...
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| Format: | Thesis (University of Nottingham only) |
| Language: | English |
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2020
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| Online Access: | https://eprints.nottingham.ac.uk/60481/ |
| _version_ | 1848799769187581952 |
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| author | Orol Gómez, Diego |
| author_facet | Orol Gómez, Diego |
| author_sort | Orol Gómez, Diego |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | The sustainable production of chemicals and fuels through microbial fermentation will play a pivotal role in reducing our dependence on fossil resources as well as decreasing global emissions of greenhouse gases, and in particular CO2. A particularly promising strategy is to produce the requisite molecules using autotrophic microbial chassis that are capable of growing on CO2 as a sole carbon source. One such chassis is Cupriavidus necator H16, formerly Rastonia eutropha. It is a Gram-negative, non-pathogenic, asporogenous bacterium found in aerobic and anaerobic, non-halophilic environments. It is a facultative, chemolithoautotroph able to grow aerobically on CO2 and H2 as sole carbon and energy source, respectively. It can also grow heterotrophically on a variety of organic substrates.
3-Hydroxypropionic acid (3-HP) is one of these potential chemicals. It is a platform chemical, which can be converted into a wide variety of acids and biodegradable polyesters, among other highly valued industrial compounds. Currently, industrial demand for 3-HP is entirely met through petrochemical routes which are associated with environmental pollution. A biological process involving genetically engineered microorganisms would potentially be a sustainable manner of production that industry will surely support and value.
Metabolic modelling has previously identified a number of potential routes to 3-HP of which a process that proceeds via β-alanine (BAL) represents the most energy efficient pathway. Whilst C. necator possesses a putative native BAL pathway, it does not presently produce 3-HP.
The current study sought to investigate the potential of the native BAL metabolic route in C. necator for the production of 3-HP, focusing our efforts on the phenotypical and enzymatic characterisation of the last two metabolic steps of the pathway, from the pyruvate-dependent transamination reaction between BAL and malonate semialdehyde (MSA) to the reduction of MSA to 3-HP. This analysis demonstrated that a putative transaminase (CnAptA) and two putative dehydrogenases (CnHpdH and CnHbdH) were largely responsible for the failure of C. necator to produce 3-HP.
Following strain development, a heterologous pathway was implemented in the organism which led to the total conversion of BAL into 3-HP. This innovation could form the basis of the future production of sustainable and commercially viable amounts of 3-HP using CO2 as the sole carbon source in C. necator H16. |
| first_indexed | 2025-11-14T20:40:55Z |
| format | Thesis (University of Nottingham only) |
| id | nottingham-60481 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T20:40:55Z |
| publishDate | 2020 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-604812025-02-28T14:53:58Z https://eprints.nottingham.ac.uk/60481/ Characterisation of the native β-alanine pathway in Cupriavidus necator H16: an attractive route towards 3-hydroxypropionic acid production. Orol Gómez, Diego The sustainable production of chemicals and fuels through microbial fermentation will play a pivotal role in reducing our dependence on fossil resources as well as decreasing global emissions of greenhouse gases, and in particular CO2. A particularly promising strategy is to produce the requisite molecules using autotrophic microbial chassis that are capable of growing on CO2 as a sole carbon source. One such chassis is Cupriavidus necator H16, formerly Rastonia eutropha. It is a Gram-negative, non-pathogenic, asporogenous bacterium found in aerobic and anaerobic, non-halophilic environments. It is a facultative, chemolithoautotroph able to grow aerobically on CO2 and H2 as sole carbon and energy source, respectively. It can also grow heterotrophically on a variety of organic substrates. 3-Hydroxypropionic acid (3-HP) is one of these potential chemicals. It is a platform chemical, which can be converted into a wide variety of acids and biodegradable polyesters, among other highly valued industrial compounds. Currently, industrial demand for 3-HP is entirely met through petrochemical routes which are associated with environmental pollution. A biological process involving genetically engineered microorganisms would potentially be a sustainable manner of production that industry will surely support and value. Metabolic modelling has previously identified a number of potential routes to 3-HP of which a process that proceeds via β-alanine (BAL) represents the most energy efficient pathway. Whilst C. necator possesses a putative native BAL pathway, it does not presently produce 3-HP. The current study sought to investigate the potential of the native BAL metabolic route in C. necator for the production of 3-HP, focusing our efforts on the phenotypical and enzymatic characterisation of the last two metabolic steps of the pathway, from the pyruvate-dependent transamination reaction between BAL and malonate semialdehyde (MSA) to the reduction of MSA to 3-HP. This analysis demonstrated that a putative transaminase (CnAptA) and two putative dehydrogenases (CnHpdH and CnHbdH) were largely responsible for the failure of C. necator to produce 3-HP. Following strain development, a heterologous pathway was implemented in the organism which led to the total conversion of BAL into 3-HP. This innovation could form the basis of the future production of sustainable and commercially viable amounts of 3-HP using CO2 as the sole carbon source in C. necator H16. 2020-07-24 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/60481/1/Thesis%20Diego%20Orol%20Gomez%20Final.pdf Orol Gómez, Diego (2020) Characterisation of the native β-alanine pathway in Cupriavidus necator H16: an attractive route towards 3-hydroxypropionic acid production. PhD thesis, University of Nottingham. Cupriavidus necator H16 3-hydroxypropionic acid β-alanine CO2 |
| spellingShingle | Cupriavidus necator H16 3-hydroxypropionic acid β-alanine CO2 Orol Gómez, Diego Characterisation of the native β-alanine pathway in Cupriavidus necator H16: an attractive route towards 3-hydroxypropionic acid production. |
| title | Characterisation of the native β-alanine pathway in Cupriavidus necator H16: an attractive route towards 3-hydroxypropionic acid production. |
| title_full | Characterisation of the native β-alanine pathway in Cupriavidus necator H16: an attractive route towards 3-hydroxypropionic acid production. |
| title_fullStr | Characterisation of the native β-alanine pathway in Cupriavidus necator H16: an attractive route towards 3-hydroxypropionic acid production. |
| title_full_unstemmed | Characterisation of the native β-alanine pathway in Cupriavidus necator H16: an attractive route towards 3-hydroxypropionic acid production. |
| title_short | Characterisation of the native β-alanine pathway in Cupriavidus necator H16: an attractive route towards 3-hydroxypropionic acid production. |
| title_sort | characterisation of the native β-alanine pathway in cupriavidus necator h16: an attractive route towards 3-hydroxypropionic acid production. |
| topic | Cupriavidus necator H16 3-hydroxypropionic acid β-alanine CO2 |
| url | https://eprints.nottingham.ac.uk/60481/ |