Effect of Trichoderma-enriched organic charcoal in the integrated wood protection strategy

Abstract

The gradual elimination of chromium from wood preservative formulations results in higher Cu leaching and increased susceptibility to wood decay fungi. Finding a sustainable strategy in wood protection has become of great interest among researchers. The objective of these in vitro studies was to demonstrate the effect of T-720-enriched organic charcoal (biochar) against five wood decay basidiomycetes isolated from strongly damaged poles. For this purpose, the antagonistic potential of Trichoderma harzianum (strain T-720) was confirmed among other four Trichoderma spp. against five brown-rot basidiomycetes in dual culture tests. T-720 was genetically transformed and tagged with the green fluorescent protein (GFP) in order to study its antagonistic mechanism against wood decay basidiomycetes. It was also demonstrated that T-720 inhibits the oxalic acid production by basidiomycetes, a well-known mechanism used by brown-rot fungi to detoxify Cu from impregnated wood. Additionally, this study evaluated the effect of biochar, alone or in combination with T-720, on Cu leaching by different preservatives, pH stabilization and prevention of wood decay caused by five basidiomycetes. Addition of biochar resulted in a significant Cu binding released from impregnated wood specimens. T-720-enriched biochar showed a significant reduction of wood decay caused by four basidiomycetes. The addition of T-720-enriched biochar to the soil into which utility poles are placed may improve the efficiency of Cr-free wood preservatives.

Influence of Soil Characteristics on Wood Biodeterioration by Brown Rot Fungi

“…Leaching of wood preservatives has been previously described as pH dependent but the absence of Cr as a fixative for Cu in wood strongly influences leaching [17]. Furthermore, wood properties such as pH, lignin type and content and extractive content can also influence the fixation of wood preservatives [44].…”

“…In 2013, the European Union put new biocide regulations in place, which significantly increase the safety and simplicity requirements of biocides used and placed on the EU market. In recent years, the wood protection industry has started to use Cr-and boron-free wood products and to develop more environmentally friendly wood modification methods [14][15][16][17]. In this context, the exposure of chemically-treated wood e.g., utility poles to soil microorganisms has resulted in the development of several heavy metal tolerance mechanisms.…”

“…In natural environments, the complexity of the interactions between soil characteristics and metal ions [30], leaching from wood preservatives [17] and adaptation of fungal communities have to be considered [8,9]. The objective of this study was to assess the influence of soil pH, humic acid and iron on wood decay.…”

Green Challenges: plant en bodemweerbaarheidtegen ondergrondse ziekten

“…Onder andere de grondstoffen die gebruikt worden in pyrolyse en de temperatuur tijdens pyrolyse lijken effect te hebben op eigenschappen van biochar en hun rol in substraatweerbarheid (Jaiswal et al 2014). Biochar pre-conditioning met micro-organismen zal de effectiviteit tegen plantenpathogenen kunnen verhogen (Ribera et al 2017;Jaiswal et al 2018).…”

Molecular tagging of biocontrol fungus Trichoderma asperellum and its colonization in soil

“…In order to gain a deeper and systematic understanding of the micro‐ecological behavioural pattern of this biocontrol fungus in colonization, survival and reproduction within the rhizosphere of plants, and to conveniently monitor the population dynamics of the artificially inoculated biocontrol fungus, it is necessary to establish effective genetic tags to discriminate it from similar microbial community members (Zhang et al ; Villarino et al ). Application of molecular tagging technology to track biocontrol microbial strains and study their colonization dynamics is an effective way to understand the colonization patterns of these micro‐organisms (Velazquez‐Robledo et al ; Bi et al ; Olarte et al ; Li et al ; Fida et al ; Ribera et al ). Additionally, in order to effectively overcome the interference of the indigenous micro‐organisms with the natural environment, the double marking method is commonly applied, such as the double markers of antimicrobial resistance and green fluorescent protein (GFP), to avoid measuring the effects of naturally antimicrobial‐resistant or fluorescent micro‐organisms (McDougal et al ; Hohmann et al ).…”