| Autor: |
PANAJOTOVA, H. N., DOBREVA, V. T., ZHEKOVA, B. Y., DELCHEV, N. D., DOBREV, G. T. |
| Předmět: |
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| Zdroj: |
Oxidation Communications; 2023, Vol. 46 Issue 4, p1011-1021, 11p |
| Abstrakt: |
Lipases are preferred industrial enzymes because they catalyse synthesis reactions in organic media. The immobilisation process improves the stability and reusability of the lipases allowing its application as a catalyst in reactions of transesterification. A wide range of functional carriers have been used for the immobilisation of lipase. Polyvinyl alcohol (PVA), as a promising carrier, provides different characteristics and properties of biocatalysts, and importantly, allows interfacial activation of the lipase. In the present study, a transesterification reaction was performed on immobilised lipase on a polysiloxane-polyvinyl alcohol hybrid matrix (PVA-SiO2 ). As a result, the optimal reaction conditions were determined to be as follows: reaction time of 12 h, the concentration, and the type of acyl acceptor 1 mmol/l butyl acetate for the PVA-SiO2 immobilised lipase. The lipase immobilised on modified epoxy-SiO2 -PVA achieved maximum activity using 0.8 mmol/l methyl oleate. The influence of various organic solvents as a medium for the transesterification reaction was also investigated. Different solvents were found to have a significant effect on the lipase activity of the two modified supports. It was observed that PVA-SiO2 immobilised lipase exhibits excellent transesterification activity in the presence of a hydrophobic reaction medium. In contrast, epoxy SiO2 -PVA immobilised lipase prefers a hydrophilic environment. The operational stability was tested by repeated batch experiments, where transesterification activity was decreased by only 10% after the lipase was reused for 5 cycles. The results from this study highlight the reaction optimal conditions for transesterification activity and stability of the immobilised lipase from Rhizopus arrhizus. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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