Enzymatic Functionalization of Wood as an Antifouling Strategy against the Marine Bacterium Cobetia marina.

Daniel Filgueira,Cristian Bolaño,Susana Gouveia,Diego Moldes

doi:10.3390/polym13213795

Abstract

The protection of wood in marine environments is a major challenge due to the high sensitivity of wood to both water and marine microorganisms. Besides, the environmental regulations are pushing the industry to develop novel effective and environmentally friendly treatments to protect wood in marine environments. The present study focused on the development of a new green methodology based on the laccase-assisted grafting of lauryl gallate (LG) onto wood to improve its marine antifouling properties. Initially, the enzymatic treatment conditions (laccase dose, time of reaction, LG concentration) and the effect of the wood specie (beech, pine, and eucalyptus) were assessed by water contact angle (WCA) measurements. The surface properties of the enzymatically modified wood veneers were assessed by X-ray photoelectron spectroscopy (XPS), Fourier transform-infrared spectroscopy (FTIR). Antifouling properties of the functionalized wood veneers against marine bacterium Cobetia marina were studied by scanning electron microscopy (SEM) and protein measurements. XPS and FTIR analysis suggested the stable grafting of LG onto the surface of wood veneers after laccase-assisted treatment. WCA measurements showed that the hydrophobicity of the wood veneers significantly increased after the enzymatic treatment. Protein measurements and SEM pictures showed that enzymatically-hydrophobized wood veneers modified the pattern of bacterial attachment and remarkably reduced the bacterium colonization. Thus, the results observed in the present study confirmed the potential efficiency of laccase-assisted treatments to improve the marine antifouling properties of wood.

Highlights

Wood is a renewable, cheap, and biodegradable bioresource with interesting mechanical properties which make it a competitive material in construction applications
All the immersed surfaces are rapidly colonized by different microorganisms leading to the formation of a biofilm, and larger organisms could colonize the substrata after the biofilm formation
Laccase-assisted hydrophobization is a promising pathway to achieve an efficient hydrophobization of wood with a low environmental impact and a competitive production cost

Summary

Introduction

Cheap, and biodegradable bioresource with interesting mechanical properties which make it a competitive material in construction applications. Wood is highly hydrophilic and very sensitive to the attack of biological organisms [2] These characteristics are a major challenge in marine environments, due to the regular wet conditions and the great number of living organisms in seawater. Under these conditions, all the immersed surfaces are rapidly colonized by different microorganisms leading to the formation of a biofilm, and larger organisms could colonize the substrata after the biofilm formation. All the immersed surfaces are rapidly colonized by different microorganisms leading to the formation of a biofilm, and larger organisms could colonize the substrata after the biofilm formation This phenomenon is commonly known as marine biofouling [3]

Methods

Results

Conclusion