| Autor: |
Guosi Li, Fucheng Zhu, Fangli Gu, Xinjian Yin, Qilin Xu, Menghua Ma, Li Zhu, Baowei Lu, Naidong Chen |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
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| Zdroj: |
Catalysts, Vol 12, Iss 6, p 587 (2022) |
| Druh dokumentu: |
article |
| ISSN: |
2073-4344 |
| DOI: |
10.3390/catal12060587 |
| Popis: |
Reaction coupling separation systems using calcium fumarate as a substrate can break the reaction equilibrium and promote the production of l-malate. However, the low reusability and stability of fumarase limit its further application. In this study, partially purified fumarase of Thermus thermophilus (87.0 U mg−1) was immobilized within konjac-κ-carrageenan beads. An amalgamation of konjac and carrageenan gum (2%) was used to form the beads, and polyethylene polyamine (0.2%) and glutaraldehyde (0.1%) were used as the cross-linking agents. The pH and temperature profiles of free and immobilized fumarases were remarkably similar. The diffusion limit of immobilized fumarase caused a decline in the maximal velocity (Vmax), whereas the kinetic constant (Km) value increased. Optimization of the parameters for biotransformation by immobilized fumarase showed that 88.3% conversion of 200 mM calcium fumarate could be achieved at 55 °C within 8 h. The beads were stored for 30 days at 4 °C with minimal loss in activity and were reusable for up to 20 cycles with 78.1% relative activity. By recycling the reaction supernatant, a total amount of 3.98 M calcium fumarate was obtained with a conversion of 99.5%, which is the highest value ever reported. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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