Immobilization of lipase onto cellulose ultrafine fiber membrane for oil hydrolysis in high performance bioreactor

Abstract

Practical application of biphasic enzymeimmobilized membrane bioreactors (EMBR) requires efficient loading of the enzyme with retention of enzymatic activity. Here, we report a method to fabricate an ultrafine fiber membrane conjugated to lipase with high levels of enzyme loading and activity retention. A cellulose acetate (CA) non-woven ultrafine fiber membrane was prepared with 200 nm nominal fiber diameter by electrospinning, followed by alkaline hydrolysis to obtain regenerated cellulose (RC). The RC ultrafine fiber membrane was oxidized by exposure to NaIO 4 , simultaneously generating aldehyde groups to couple with pentaethylenehexamine (PEHA) as a spacer for lipase immobilization. A biphasic EMBR was assembled with the PEHAmodified and lipase-immobilized membranes. The effect of operation variables, namely aqueous-phase system, reaction pH, accelerant (sodium taurocholate) content, reaction temperature, and membrane usage on the performance of this bioreactor was investigated with the hydrolysis of olive oil. A bioreactor activity as high as 9.83 9 10 4 U/m 2 was obtained under optimum operational conditions.

Encapsulation and immobilization of papain in electrospun nanofibrous membranes of PVA cross-linked with glutaraldehyde vapor

“…Hence, the decrease in the enzymatic activity can be explained due to the high amount of encapsulated papain during the electrospinning process. This factor, in combination with the nanofiber crosslinking reaction, could limit the diffusion of the substrate to the active site of the immobilized enzyme [33,42]. In this study, the maximum enzymatic activity reached by the papain immobilized in electrospun PVA membranes was approximately 88% that of the free papain (1.22 × 10 −2 U/mg).…”

“…This aldehyde is widely used as a crosslinking agent in enzyme immobilization [25,33]. Typically, a PVA nanofiber mat was left in contact with glutaraldehyde vapor for various time periods inside a desiccator.…”

Activation and deformation of immobilized lipase on self-assembled monolayers with tailored wettability

“…The Michaelis constant (K m ) and the maximum hydrolysis reaction rate (V max ) were calculated (ESI, † eqn (S12)), [34][35] and the results are presented in Fig. The Michaelis constant (K m ) and the maximum hydrolysis reaction rate (V max ) were calculated (ESI, † eqn (S12)), [34][35] and the results are presented in Fig.…”

Electrospinning-Based Nanobiosensors

“…Such nanofibrous mats, when hosting immobilised enzymes, combine simultaneously the biocatalytic function of enzymes and their separation from end products, performed with the help of a selective membrane, which is a typical mode for running continuous catalytic processes in enzymatic membrane-bioreactors [31][32][33]. Similarly, electrospun nanofibrous membrane have been involved recently in the fabrication of enzymatic membrane-bioreactors [34][35][36].…”