Effect of sub- and supercritical CO2 treatment on the properties of Pseudomonas cepacia lipase

• Published in: Enzyme and microbial technology Vol. 53; no. 2; pp. 110 - 117
• Main Authors: Chen, Dawei, Zhang, Houjin, Xu, Jing, Yan, Yunjun
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 10.07.2013
• Subjects: Acetone - pharmacology; Burkholderia cepacia - drug effects; Burkholderia cepacia - enzymology; Carbon Dioxide - pharmacology; Compressed carbon dioxide; Enzyme Stability; Esterification - drug effects; Fluorescence spectra; Fourier transform-infrared spectrometry (FT-IR); Hot Temperature; Lipase - chemistry; Lipase - metabolism; Organic solvent tolerance; Pentanols - pharmacology; Protein Structure, Secondary; Protein Structure, Tertiary; Pseudomonas cepacia; Pseudomonas cepacia lipase (PCL); Solvents - chemistry; Solvents - pharmacology; Spectroscopy, Fourier Transform Infrared; Thermal stability; Organic solvent tolerance; Fourier transform-infrared spectrometry (FT-IR); Fluorescence spectra; Thermal stability; Compressed carbon dioxide; Pseudomonas cepacia lipase (PCL)
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2013.04.005

•Most compressed CO2 treatments significantly enhanced PCL esterification activity.•High pressure treatment facilitated PCL's esterification reactions.•The secondary and tertiary structure changes were responsible for activity variations.•The stability of PCL significantly decreased in esterification after supercritical treatment. In this work, we have investigated the influences of sub- and supercritical CO2 treatment on the properties of Pseudomonas cepacia lipase (PCL), including its esterification and transesterification activities, structural changes and stability. Results demonstrated that exposure time to subcritical CO2 treatment had a negative effect on PCL transesterification activity whereas exposure time to supercritical CO2 treatment had a positive effect. But generally, most compressed treatments significantly enhanced PCL esterification activity. Conformational analysis by FT-IR and fluorescence emission spectra revealed that enhanced activities after supercritical CO2 treatment were correlated with the secondary and tertiary structural changes of PCL. Secondary structure changes also appeared to be responsible for enhancement of PCL activities by subcritical CO2 treatment. Compared to native PCL, treated PCL's esterification activity significantly decreased in hydrophilic organic media, while transesterification activity significantly increased in tert-amyl alcohol and acetone. After supercritical treatment, the thermal stability of PCL significantly decreased in esterification reactions, however, there was no significant difference in transesterification reactions.