The fabrication of a high performance enzymatic hybrid membrane reactor (EHMR) containing immobilized Candida rugosa lipase (CRL) onto graphene oxide nanosheets-blended polyethersulfone membrane

• Published in: Journal of membrane science Vol. 613; p. 118435
• Main Authors: Jafarian, Faranak, Bordbar, Abdol-Khalegh, Razmjou, Amir, Zare, Atefeh
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2020
• Subjects: Candida rugosa lipase immobilization; Enzymatic hybrid membrane reactor; Graphene oxide nanosheets; Polyethersulfone; Stability; Polyethersulfone; Candida rugosa lipase immobilization; Enzymatic hybrid membrane reactor; Stability; Graphene oxide nanosheets
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2020.118435

Recently, membrane-immobilized enzyme as an affordable bioreactor has been explored in various fields such as biodiesel production and biosensing because of the reusability of the biocatalyst, increasing its stability and being a low-cost separating unit for producing pure products. Usually, membrane modification could affect the surface morphology and hydrophilicity to make them appropriate for enzyme immobilization. In this context, the modified nanocomposite membranes of polyethersulfone (PES) with various percentages (x: 0.00, 0.25, 0.50, 1.00, 2.00, 3.00) of the graphene oxide nanosheets (GON) named (PGx) are synthesized through the phase inversion technique. The enzymatic hybrid membrane reactors (EHMRs) are provided through the Candida rugosa lipase (CRL) immobilization on the synthesized hybrid membranes. The structure and surface functionalities of the synthesized GON and hybrid membrane are characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and attenuated total reflection (ATR), respectively. The effect of the GON incorporation and CRL immobilization on the morphology of the membrane are explored through field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), contact angle goniometry, and surface free energy analysis. After measuring the porosity of the hybrid membranes with different amounts of GON, their performance, before and after CRL immobilization, are studied through pure water flux. The effective parameters on the activity and performance of EHMR such as GON percentages, CRL initial concentration, immobilization time, and storage condition are accurately optimized. The examination of the relative activity, reusability, and product permeability display that EHMR with 1.00% of GON (EHMR1) is the most efficient between EHMRs with different percentages of GON. Moreover, EHMR1 exhibits the enhancement in pH and thermal stability compared with free CRL and even the immobilized CRL on GON. While the storage stability of the wet- EHMR1 is higher than that of the dry-EHMR1, the stored wet- EHMR1 at 4 °C is more stable than room temperature. Because of these advantages, it is recommended that this bioactive membrane could be a passable candidate for application in the environmental, analytical, and industrial processes. [Display omitted] •The Candida rugosa lipase was effectively immobilized on graphene oxide-blended polyethersulfone membrane.•The nanocomposite membrane display suitable performance through pure water flux before and after enzyme immobilization.•The enzymatic hybrid membrane reactors (EHMRs) composed of 1% graphene oxide nanosheets (GONs) present excellent catalytic activity, reusability, and product permeability.•The significant improvement in pH and thermal stability was provided by fabricated bioactive membrane compared to free enzyme.