Optimised Protocol for Drying Aqueous Enzyme Solutions in Organic Solvents – Comparison of Free and Immobilised Candida antarctica Lipase B

• Published in: ChemCatChem
• Main Authors: Tjørnelund, Helena D., Brask, Jesper, Woodley, John M., Peters, Günther H. J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2022
• Subjects: Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1002/cctc.202201207; https://onlinelibrary.wiley.com/doi/pdf/10.1002/cctc.202201207; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/cctc.202201207

Abstract Here, we propose an optimised protocol for controlling the initial water activity (a w ) in organic reaction mixtures with soluble lipase to ensure reproducible and consistent enzyme activity measurements. Pre‐equilibration above saturated salt solutions was used to set a w of the reaction media, where a w was tracked with a hygrometer. Consistent stirring of the suspension and volume correction to compensate for solvent evaporation were found to be critical. The protocol was tested on Candida antarctica lipase B (CALB) in soluble and immobilised forms in three organic solvents (acetonitrile, methyl tert‐ butyl ether, and hexane) at four different water activities ranging from 0.12 to 0.97. Soluble and immobilised CALB had similar a w ‐profiles and showed the highest enzyme activity in hexane. The optimised protocol expands the possibility to study enzyme kinetics from immobilised enzymes to soluble enzymes.