Constructing a continuous flow bioreactor based on a hierarchically porous cellulose monolith for ultrafast and nonstop enzymatic esterification/transesterification

Authors: XIAO, YUQIN - Chinese Academy Of Agricultural Sciences; ZHENG, MINGMING - Chinese Academy Of Agricultural Sciences; Liu, Zengshe - Kevin; SHI, JIE - Chinese Academy Of Agricultural Sciences; HUANG, FENGHONG - Chinese Academy Of Agricultural Sciences; LUO, XIAOGANG - Wuhan Institute Of Technology

Submitted to: ACS Sustainable Chemistry & Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/28/2018
Publication Date: 11/30/2018
Citation: Xiao, Y., Zheng, M., Liu, Z., Shi, J., Huang, F., Luo, X. 2018. Constructing a continuous flow bioreactor based on a hierarchically porous cellulose monolith for ultrafast and nonstop enzymatic esterification/transesterification. ACS Sustainable Chemistry & Engineering. 7(2):2056-2063. https://doi.org/10.1021/acssuschemeng.8b04471.
DOI: https://doi.org/10.1021/acssuschemeng.8b04471

Interpretive Summary: In this research, we discovered that an enzyme loaded on a cellulose acetate based monolith with an inter-connected macropore and mesopore structure efficiently catalyzed the esterification/tranesterification of sterol and fatty acids. Continuous flow bioreactors have received increasing attention due to their automated high-throughput continuous processing. This continuous process of loading an enzyme on porous materials increased the kinetic parameter by 66.4-fold, and increased the catalysis effect by 6.1-fold on the esterification reaction. The enzyme can be reused many times without losing their catalytic activities. The formed sterol esters can be used as an ingredient in the pharmaceutical and food industries.

Technical Abstract: Continuous flow bioreactors have received increasing attention due to their automated high-throughput continuous processing. Cellulose acetate (CA), which is eco-friendly, renewable, and easily accessed, was made into monoliths with interconnected macropores and mesopores on the skeleton by the method of thermally induced phase separation (TIPS). A continuous flow bioreactor was prepared by the immobilization of lipase on the skeleton of CA monolith (CA-MN). Benefiting from the hierarchical structure, the monolith skeletons with mesopores (15.6 nm) serve as a suitable space for lipase immobilization, and the interconnected macropores (3-5 µm) with controllable permeability make the accommodated lipase more accessible to the substrates. Based on this monolithic bioreactor, an ultrafast continuous esterification/transesterification method with more than 90% conversion was developed. Compared to conventional batch reaction modes, the kinetic parameter Vm/Km increased by 66.4-fold, and the catalysis effect (CE) increased by 6.1-fold. The monolithic continuous flow bioreactor (MCFB) enabled enzymatic esterification/transesterification to be completed in 10 min and to continue uninterrupted for 200 h, which set the highest productivity record for phytosterol esters (422 g/g monolith) without loss of catalytic activity. The novel MCFB with high catalytic activity, high stability, easy separation, scale-up, and automation introduces new expectations for sustainable development of industrial catalysis.