Laccase immobilization on bacterial nanocellulose membranes: Antimicrobial, kinetic and stability properties.
This work studied the physical immobilization of a commercial laccase on bacterial nanocellulose (BNC) aiming to identify the laccase antibacterial properties suitable for wound dressings. Physico-chemical analysis demonstrates that the BNC structure is manly formed by pure crystalline Iα cellulose. The pH optimum and activation energy of free laccase depends on the substrate employed corresponding to pH 6, 7, 3 and 57, 22, 48kJmol(-1) for 2,6-dimethylphenol (DMP), catechol and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), respectively. The Michaelis-Menten constant (Km) value for the immobilized laccase (0.77mM) was found to be almost double of that of the free enzyme (0.42mM). However, the specific activities of immobilized and free laccase are similar suggesting that the cage-like structure of BNC allows entrapped laccase to maintain some flexibility and favour substrate accessibility. The results clearly show the antimicrobial effect of laccase in Gram-positive (92%) and Gram-negative (26%) bacteria and cytotoxicity acceptable for wound dressing applications.
2C2T-Centre for Textile Science and Technology, Textile Engineering Department, University of Minho, Campus Azurem, 4800-058 Guimarães, Portugal. Electronic address: lilianamargarida.1@gmail.com.
Liliana M P
LM
Sampaio
Centre for Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal. Electronic address: padraoj@gmail.com.
Jorge
J
Padrão
2C2T-Centre for Textile Science and Technology, Textile Engineering Department, University of Minho, Campus Azurem, 4800-058 Guimarães, Portugal. Electronic address: pg26020@alunos.uminho.pt.
Jorge
J
Faria
Centre for Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal. Electronic address: jpsilva@deb.uminho.pt.
João P
JP
Silva
CeNTI-Centro de Nanotecnologia e Materiais Técnicos, Funcionais e Inteligentes, Rua Fernando Mesquita 2785, 4760-034 V. N. Famalicão, Portugal. Electronic address: CSilva@centi.pt.
Carla J
CJ
Silva
Centre for Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal. Electronic address: fdourado@deb.uminho.pt.
Fernando
F
Dourado
2C2T-Centre for Textile Science and Technology, Textile Engineering Department, University of Minho, Campus Azurem, 4800-058 Guimarães, Portugal. Electronic address: azille@2c2t.uminho.pt.
Andrea
A
Zille
D016475:3T3 Cells; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002482:Cellulose / Q000737:chemistry*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects; D041821:Gluconacetobacter; D007700:Kinetics; D042845:Laccase / Q000737:chemistry* / Q000494:pharmacology; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry; D051379:Mice; D012834:Silver / Q000737:chemistry / Q000494:pharmacology; D020037:Sordariales / Q000201:enzymology; D013211:Staphylococcus aureus / Q000187:drug effects
D000900:Anti-Bacterial Agents; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D012834:Silver; D002482:Cellulose; D042845:Laccase
Antimicrobial; Bacterial cellulose; Cytotoxicity; Immobilization; Laccase; Wound dressing