Supercritical Fluids Are Superior Media for Catalysis by Cross-Linked Enzyme Microcrystals of Subtilisin Carlsberg

• Published in: Biotechnology progress Vol. 17; no. 2; pp. 355 - 358
• Main Authors: Fontes, Nuno, Almeida, M. Conceição, Garcia, Silvia, Peres, Célia, Partridge, Johann, Halling, Peter J., Barreiros, Susana
• Format: Journal Article
• Language: English
• Published: USA American Chemical Society 2001; American Institute of Chemical Engineers
• Subjects: Bioconversions. Hemisynthesis; Biological and medical sciences; Biotechnology; Catalysis; Crystallization; Esterification; Fundamental and applied biological sciences. Psychology; Kinetics; Methods. Procedures. Technologies; Subtilisins - chemistry; Subtilisins - metabolism; Peptidases; Serine endopeptidases; Crosslinked state; Enzyme; Reaction medium; Supercritical solvent; Hydrolases; Enzymatic catalysis; Subtilisin; Microcrystal
• ISSN: 8756-7938; 1520-6033
• DOI: 10.1021/bp000148m

We report on the performance of cross‐linked enzyme microcrystals (CLECs) of subtilisin Carlsberg in supercritical fluids (SC‐fluids). The catalytic activity of CLECs in SC‐ethane was found to be 2‐ to 10‐fold greater than in hexane under the same conditions, using CLECs dried by propanol washing. Air‐dried CLECs and lyophilized powders showed much lower activities, reflecting the same hydration hysteresis effects as in organic solvents. Reaction rates were much lower in SC‐CO2, especially at higher water activity, probably as a result of acid‐base effects of carbonic acid on the enzyme.