Carbon nanoparticle-stabilized Pickering emulsion as a sustainable and high-performance interfacial catalysis platform for enzymatic esterification/transesterification

Authors: DONG, ZHE - Chinese Academy Of Agricultural Sciences; Liu, Zengshe - Kevin; SHI, JIE - Chinese Academy Of Agricultural Sciences; TANG, HU - Chinese Academy Of Agricultural Sciences; XIANG, XIA - Chinese Academy Of Agricultural Sciences; HUANG, FENGHONG - Chinese Academy Of Agricultural Sciences; ZHENG, MINGMING - Chinese Academy Of Agricultural Sciences

Submitted to: ACS Sustainable Chemistry & Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/2019
Publication Date: 3/25/2019
Citation: Dong, Z., Liu, Z., Shi, J., Tang, H., Xiang, X., Huang, F., Zheng, M. 2019. Carbon nanoparticle-stabilized Pickering emulsion as a sustainable and high-performance interfacial catalysis platform for enzymatic esterification/transesterification. ACS Sustainable Chemistry & Engineering. 7(8):7619-7629.
DOI: https://doi.org/10.1021/acssuschemeng.8b05908

Interpretive Summary: In this research, we discovered that an enzyme loaded on mesoporous carbon spheres efficiently catalyzed the esterification/transesterification of sterols and fatty acids. The performance of the loaded enzyme showed the shortest reaction time, minimal amount of catalyst and the highest final products. This technology will benefit pharmaceuticals and foods industries.

Technical Abstract: A sustainable and efficient reaction system for enzymatic oil modification is imperative for the food industry. Given the interfacial activation effect of lipase, the sufficient oil-water interface is vital for excellent catalytic activity of lipase. In the present study, a Pickering emulsion reaction system was prepared through directly using reactants as the oil phase and stabilized by mesoporous carbon spheres (MCS) after immobilization of lipase AYS (Candida rugosa, lipase@MCS). Lipase@MCS worked as both the emulsifier and catalyst. Each droplet in the Pickering emulsion was regarded as a microreactor with the reactants in the oil phase, and the removal of the product H2O “pushed” the reaction forward. Taking advantage of the adequate oil-water interface for “lid” opening of lipase and rapid mass transfer in MCS, the Pickering emulsion exhibited excellent enzymatic activity toward phytosterol esterification and transesterification, achieving 95.0% conversion after 1.5 h and catalytic efficiency (CE) of 6.8 mmol g-1 h-1 under nonequilibrium conditions. It is the best performance reported currently with the shortest reaction time, minimal amount of catalyst, and the highest CE (19-fold higher than free lipase one-phase reaction system). Immobilization of lipase on the MCS not only endowed the lipase with exceptional recyclability but also afforded a shield to protect the enzyme from deactivation in a harsh environment, as evidenced by the thermotolerance and recycling test results. This paper paves the way to advancing progress in enzyme-immobilized Pickering emulsion as a sustainable and high-efficiency platform for biocatalysis application.