New findings about the lipase acetylation of nanofibrillated cellulose using acetic anhydride as acyl donor

Mojca Božič; Vera Vivod; Sabina Kavčič; Maja Leitgeb; Vanja Kokol

doi:10.1016/j.carbpol.2015.02.061

New findings about the lipase acetylation of nanofibrillated cellulose using acetic anhydride as acyl donor

Carbohydr Polym. 2015 Jul 10:125:340-51. doi: 10.1016/j.carbpol.2015.02.061. Epub 2015 Mar 7.

Authors

Mojca Božič¹, Vera Vivod², Sabina Kavčič³, Maja Leitgeb³, Vanja Kokol⁴

Affiliations

¹ University of Maribor, Faculty of Mechanical Engineering, Institute for Engineering Materials and Design, Smetanova ul. 17, SI-2000 Maribor, Slovenia. Electronic address: mojca.bozic@um.si.
² University of Maribor, Faculty of Mechanical Engineering, Institute for Engineering Materials and Design, Smetanova ul. 17, SI-2000 Maribor, Slovenia.
³ University of Maribor, Faculty of Chemistry and Chemical Engineering, Laboratory for Separation Processes and Product Design, Smetanova ul. 17, SI-2000 Maribor, Slovenia.
⁴ University of Maribor, Faculty of Mechanical Engineering, Institute for Engineering Materials and Design, Smetanova ul. 17, SI-2000 Maribor, Slovenia. Electronic address: vanja.kokol@um.si.

PMID: 25857991
DOI: 10.1016/j.carbpol.2015.02.061

Abstract

The acetylation efficiency of nanofibrillated cellulose (NFC) with acetic anhydride as acetyl donor was studied using lipase from Aspergillus niger in a mixture of dimethyl sulphoxide (DMSO) and phosphate buffer solution at ambient conditions and in supercritical carbon dioxide (scCO2). The chemical acetylation of NFC with comparable ester content was carried out for comparison. The ATR-FTIR, solid-state CP/MAS (13)C NMR and DSC analyses revealed that, besides the enzyme-catalysed acetylation, predominantly appearing at the C-6 position of cellulose hydroxyls, a strong and stable acyl-enzyme intermediate attachment also occurred on the NFC via Maillard reaction. Enzymatic acetylation via attached acyl-enzyme complex on NFC yielded high hydophobicity (contact angle of 84±9°), whereas the chemical acetylation with comparable ester content resulted in a much lower hydrophobic surface with a contact angle of 33±3°. Finally, the adsorption capacity profiles of lysozyme and BSA proteins on native, chemically and enzymatically acetylated NFC as a function of the pH medium were determined.

Keywords: Acetylation; Hydrophobicity; Lipase; Nanofibrillated celluloses; Selective protein adsorption.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acetic Anhydrides / chemistry*
Acetylation
Biocatalysis
Cellulose / analogs & derivatives*
Cellulose / chemical synthesis
Cellulose / chemistry
Lipase / chemistry*
Nanofibers / chemistry*

Substances

Acetic Anhydrides
acetic anhydride
acetylcellulose
Cellulose
Lipase