Automatic Control of Chemolithotrophic Cultivation of <i>Cupriavidus necator</i>: Optimization of Oxygen Supply for Enhanced Bioplastic Production
Gas fermentation is an upcoming technology to convert gaseous substrates into value-added products using autotrophic microorganisms. The hydrogen-oxidizing bacteria <i>Cupriavidus necator</i> efficiently uses CO<sub>2</sub> as its sole carbon source, H<sub>2</sub>...
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| Format: | Article |
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MDPI AG
2023-06-01
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| Series: | Fermentation |
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| Online Access: | https://www.mdpi.com/2311-5637/9/7/619 |
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| author | Vera Lambauer Alexander Permann Zdeněk Petrášek Vanja Subotić Christoph Hochenauer Regina Kratzer Markus Reichhartinger |
| author_facet | Vera Lambauer Alexander Permann Zdeněk Petrášek Vanja Subotić Christoph Hochenauer Regina Kratzer Markus Reichhartinger |
| author_sort | Vera Lambauer |
| collection | DOAJ |
| description | Gas fermentation is an upcoming technology to convert gaseous substrates into value-added products using autotrophic microorganisms. The hydrogen-oxidizing bacteria <i>Cupriavidus necator</i> efficiently uses CO<sub>2</sub> as its sole carbon source, H<sub>2</sub> as electron donor and O<sub>2</sub> as electron acceptor. Surplus CO<sub>2</sub> is stored in microbial storage material poly-(<i>R</i>)-3-hydroxybutyrate. O<sub>2</sub> supply is the most critical parameter for growth and poly-(<i>R</i>)-3-hydroxybutyrate formation. A narrow O<sub>2</sub> optimum between ~0.2 and ~4 mg/L was previously reported. Here, a standard benchtop bioreactor was redesigned for autotrophic growth of <i>C. necator</i> on explosive mixtures of CO<sub>2</sub>, H<sub>2</sub> and O<sub>2</sub>. The bioreactor was equipped with mass flow control units and O<sub>2</sub> and CO<sub>2</sub> sensors. A controller for automated gas dosage based on a mathematical model including gas mass transfer, gas consumption and sensor response time was developed. Dissolved O<sub>2</sub> concentrations were adjusted with high precision to 1, 2 and 4% O<sub>2</sub> saturation (0.4, 0.8 and 1.5 mg/L dissolved O<sub>2</sub>, respectively). In total, up to 15 g/L cell dry weight were produced. Residual biomass formation was 3.6 ± 0.2 g/L under all three O<sub>2</sub> concentrations. However, poly-(<i>R</i>)-3-hydroxybutyrate content was 71, 77 and 58% of the cell dry weight with 1, 2 and 4% dissolved O<sub>2</sub>, respectively. |
| first_indexed | 2024-03-11T01:05:57Z |
| format | Article |
| id | doaj.art-b5db9bfb4384426a9117804d400c9710 |
| institution | Directory Open Access Journal |
| issn | 2311-5637 |
| language | English |
| last_indexed | 2024-03-11T01:05:57Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fermentation |
| spelling | doaj.art-b5db9bfb4384426a9117804d400c97102023-11-18T19:16:00ZengMDPI AGFermentation2311-56372023-06-019761910.3390/fermentation9070619Automatic Control of Chemolithotrophic Cultivation of <i>Cupriavidus necator</i>: Optimization of Oxygen Supply for Enhanced Bioplastic ProductionVera Lambauer0Alexander Permann1Zdeněk Petrášek2Vanja Subotić3Christoph Hochenauer4Regina Kratzer5Markus Reichhartinger6Austrian Centre of Industrial Biotechnology (ACIB), Krenngasse 37, A-8010 Graz, AustriaAustrian Centre of Industrial Biotechnology (ACIB), Krenngasse 37, A-8010 Graz, AustriaInstitute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12/I, A-8010 Graz, AustriaInstitute of Thermal Engineering, Graz University of Technology, Inffeldgasse 25B, A-8010 Graz, AustriaInstitute of Thermal Engineering, Graz University of Technology, Inffeldgasse 25B, A-8010 Graz, AustriaInstitute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12/I, A-8010 Graz, AustriaInstitute of Automation and Control, Graz University of Technology, Inffeldgasse 21B, A-8010 Graz, AustriaGas fermentation is an upcoming technology to convert gaseous substrates into value-added products using autotrophic microorganisms. The hydrogen-oxidizing bacteria <i>Cupriavidus necator</i> efficiently uses CO<sub>2</sub> as its sole carbon source, H<sub>2</sub> as electron donor and O<sub>2</sub> as electron acceptor. Surplus CO<sub>2</sub> is stored in microbial storage material poly-(<i>R</i>)-3-hydroxybutyrate. O<sub>2</sub> supply is the most critical parameter for growth and poly-(<i>R</i>)-3-hydroxybutyrate formation. A narrow O<sub>2</sub> optimum between ~0.2 and ~4 mg/L was previously reported. Here, a standard benchtop bioreactor was redesigned for autotrophic growth of <i>C. necator</i> on explosive mixtures of CO<sub>2</sub>, H<sub>2</sub> and O<sub>2</sub>. The bioreactor was equipped with mass flow control units and O<sub>2</sub> and CO<sub>2</sub> sensors. A controller for automated gas dosage based on a mathematical model including gas mass transfer, gas consumption and sensor response time was developed. Dissolved O<sub>2</sub> concentrations were adjusted with high precision to 1, 2 and 4% O<sub>2</sub> saturation (0.4, 0.8 and 1.5 mg/L dissolved O<sub>2</sub>, respectively). In total, up to 15 g/L cell dry weight were produced. Residual biomass formation was 3.6 ± 0.2 g/L under all three O<sub>2</sub> concentrations. However, poly-(<i>R</i>)-3-hydroxybutyrate content was 71, 77 and 58% of the cell dry weight with 1, 2 and 4% dissolved O<sub>2</sub>, respectively.https://www.mdpi.com/2311-5637/9/7/619CO<sub>2</sub> valorizationhydrogen oxidizing bacteriaKnallgas bacteriagas fermentationbioprocess controlpolyhydroxyalkanoate |
| spellingShingle | Vera Lambauer Alexander Permann Zdeněk Petrášek Vanja Subotić Christoph Hochenauer Regina Kratzer Markus Reichhartinger Automatic Control of Chemolithotrophic Cultivation of <i>Cupriavidus necator</i>: Optimization of Oxygen Supply for Enhanced Bioplastic Production Fermentation CO<sub>2</sub> valorization hydrogen oxidizing bacteria Knallgas bacteria gas fermentation bioprocess control polyhydroxyalkanoate |
| title | Automatic Control of Chemolithotrophic Cultivation of <i>Cupriavidus necator</i>: Optimization of Oxygen Supply for Enhanced Bioplastic Production |
| title_full | Automatic Control of Chemolithotrophic Cultivation of <i>Cupriavidus necator</i>: Optimization of Oxygen Supply for Enhanced Bioplastic Production |
| title_fullStr | Automatic Control of Chemolithotrophic Cultivation of <i>Cupriavidus necator</i>: Optimization of Oxygen Supply for Enhanced Bioplastic Production |
| title_full_unstemmed | Automatic Control of Chemolithotrophic Cultivation of <i>Cupriavidus necator</i>: Optimization of Oxygen Supply for Enhanced Bioplastic Production |
| title_short | Automatic Control of Chemolithotrophic Cultivation of <i>Cupriavidus necator</i>: Optimization of Oxygen Supply for Enhanced Bioplastic Production |
| title_sort | automatic control of chemolithotrophic cultivation of i cupriavidus necator i optimization of oxygen supply for enhanced bioplastic production |
| topic | CO<sub>2</sub> valorization hydrogen oxidizing bacteria Knallgas bacteria gas fermentation bioprocess control polyhydroxyalkanoate |
| url | https://www.mdpi.com/2311-5637/9/7/619 |
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