Cationised fibre-based cellulose multi-layer membranes for sterile and high-flow bacteria retention and inactivation

Kokol, Vanja (author), Kos, Monika (author), Vivod, Vera (author), Gunde-Cimerman, Nina (author)

Low-cost, readily available, or even disposable membranes in water purification or downstream biopharma processes are becoming attractive alternatives to expensive polymeric columns or filters. In this article, the potential of microfiltration membranes prepared from differently orientated viscose fibre slivers, infused with ultrafine quaternised (qCNF) and amino-hydrophobised (aCNF) cellulose nanofibrils, were investigated for capturing and deactivating the bacteria from water during vacuum filtration. The morphology and capturing mechanism of the single- and multi-layer structured membranes were evaluated using microscopic imaging and colloidal particles. They were assessed for antibacterial efficacy and the retention of selected bacterial species (Escherichia coli, Staphylococcus aureus, Micrococcus luteus), differing in the cell envelope structure, hydrodynamic biovolume (shape and size) and their clustering. The aCNF increased biocidal efficacy significantly when compared to qCNF-integrated membrane, although the latter retained bacteria equally effectively by a thicker multi-layer structured membrane. The retention of bacterial cells occurred through electrostatic and hydrophobic interactions, as well as via interfibrous pore diffusion, depending on their physicochemical properties. For all bacterial strains, the highest retention (up to 100% or log 6 reduction) at >50 L/h∗bar∗m$^2$ flow rate was achieved with a 4-layer gradient-structured membrane containing different aCNF content, thereby matching the performance of industrial polymeric filters used for removing bacteria.

• Language: English
• Keywords: fibrous membrane, cationised cellulose nanofibrils, amino-hydrophobised cellulose nanofibrils, antibacterial activity, multi-layer structure, flux, bacteria retention
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 23 str.
• Numbering: Vol. 13, iss. 3, art. 284
• PID: 20.500.12556/RUL-155611
• UDC: 577:620.3
• ISSN on article: 2077-0375
• DOI: 10.3390/membranes13030284
• COBISS.SI-ID: 144515331
• Publication date in RUL: 08.04.2024

Record is a part of a journal

• Title: Membranes
• Shortened title: Membranes
• Publisher: MDPI
• ISSN: 2077-0375
• COBISS.SI-ID: 519125529

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: fibrozne membrane, kationizirani celulozni nanofibrili, amino-hidrofobizirani celulozni nanofibrili, protibakterijska aktivnost, večplastna struktura, tok, zadrževanje bakterij