**Conflict of interest**

with ZnNps or AgNps which significantly inhibited the growth of the microorganism, reduc-

Regarding methods of treatment against wood degradation, there are currently several methods of protection against decomposition caused by biological agents. From these, organic compounds based on quaternary ammonium salts were the most used. Studies conducted to determine the antimicrobial activity of three biocides against *Pseudomonas fluorescens*, *Staphylococcus equorum*, *Bacillus cereus*, *Bacillus muralis*, *Sporosarcina aquimarina, Rhodococcus fascians*, and some fungi species such as *Chaetomium globosum*, *Penicillium citreonigrum*, *Cladosporium cladosporioides 1*, *Acremonium strictum*, *Aspergillus fumigatus* and *Cladosporium cladosporioides 2*, all isolated from wood or brick surfaces, showed that species such as *Staphylococcus equorum*, *Bacillus cereus*, *Sporosarcina aquimarina*, *Rhodococcus fascieni, Cladosporium cladosporioides*, and *Acremonium strictum* have a high susceptibility to quaternary ammonium biocides [85]. Thus, the wood objects with a historical value can be efficiently disinfected by three times application of a biocide (30% v/v) which contains dodecyl dimethyl ammonium chloride, citric acid, propiconazole, and propanol [85]. The mechanism of action of ammonium quaternary salts is based on the dissolution of certain sites from cell walls, which results in the loss of microbial cell integrity, followed by exposure of cell content and release of the material out of the cell, followed by degradation of proteins, of nucleic acids,

Protecting degradation of wood by biological agents can also be done without biocides based on quaternary ammonium salts. A wood protection variant is based on the application of a titanium isopropoxide gel and ammonium cerium nitrate as a stabilizer for wood treatment [86]. As a mechanism of action, it is assumed that the hydrolysis of titanium isopropoxide is initiated by the wood-based OH groups as well as by the moisture in the

and thus limiting the direct exposure of micro- or nanopores of wood to fungal hydrolytic enzymes. Studies conducted on Norway spruce have shown that this method can be protected against degradation by biological agents such as *Gloeophyllum trabeum*, *Rhodonia* 

The maintaining of wood quality in time is usually achieved with the help of preservatives. These are individual chemical compounds or mixtures that make wood less susceptible to attack from a large variety of degradative factors or organisms. These organisms include insects, marine borers, and various types of fungi such as stain and decay. Some of these chemicals are effective against a wide range of organisms, while others are very specific and

This chapter received financial support from MCI-UEFISCDI by the project: 51PCCDI/2018.

which seals the wood surface

ing the mass loss of impregnated wood samples subjected to fungal attack [83].

and cell lysis, the latter caused by autolytic enzymes [85].

cellular wood wall resulting in a layer of cerium-doped TiO2

*placenta,* and *Coniophora puteana*.

86 New Uses of Micro and Nanomaterials

protect wood from only one type of organism.

**6. Conclusions**

**Acknowledgements**

The author(s) declared no potential conflicts of interest.
