The present study shows that isolates of P. vitreus have an extraordinary capacity to induce substantial permeability changes in heartwood of P. abies without causing significant losses in impact bending strength. The degradation of pit membranes by P. vitreus is an important aspect that could also have significant benefits in wood protection processes. Further studies are currently in progress with the objective of optimising the uniformity of wood colonisation and duration of incubation, so as to improve the permeability of water-borne wood preservatives or hydrophobic substances applied by brushing, dipping and impregnation.

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A new approach for protecting wood materials from fungal degradation through a non-biocidal inorganic system of a TiO2/Ce xerogel.

In this study, changes in the vibro-mechanical properties of fungi-treated wood, during sorption and desorption at different humidity levels, were investigated. Norway spruce resonance wood (with uniform narrow annual rings and high tonal quality for musical instrument craftsmanship) was incubated with Physisporinus vitreus for 36 weeks. Stiffness, internal friction, and tonal performance indices of control (untreated) and fungi-treated wood were compared after exposure to a stepwise variation of relative humidity. It was demonstrated that fungal treatment increased the internal friction and decreased the specific modulus of elasticity, during reduction of wood density. Internal friction of both control and fungi-treated wood significantly increased during dynamic sorption, especially during early stages (hours) of each humidity change step. Both specific modulus of elasticity and internal friction showed a hysteretic behavior during humidity variation cycles. Hysteresis was smaller in fungitreated wood. Also, tonal performance indices were improved after fungal treatment and showed a reduced variation at different relative humidity conditions. Dynamic vapor sorption tests and FT-IR microscopy studies revealed changes in hygroscopicity and the supramolecular structure of wood, which may explain the observed vibrational behavior. Less dependency of wood vibrational properties to the variation of the ambient humidity is important for the acoustic performance of string instruments.

Trichoderma spp. are ubiquitous soil-borne fungi that are widely used in biological control to promote and regulate healthy plant growth, as well as protect against plant pathogens. However, as with many biological materials, the relative instability of Trichoderma propagules limits its practical use in industrial applications. Therefore, there has been significant research interest in developing novel formulations with various carrier substances that are compatible with these fungal propagules and can enhance the shelf-life and overall efficacy of the Trichoderma. To this end, herein, we investigate the use of a variety of biopolymers and nanoparticles for the stabilization of Trichoderma atrobrunneum T720 conidia for biological control. The best-performing agents—agar and cellulose nanocrystals (CNC)—were then used in the preparation of oil-in-water emulsions to encapsulate conidia of T720. Emulsion properties including oil type, oil:water ratio, and biopolymer/particle concentration were investigated with respect to emulsion stability, droplet size, and viability of T720 conidia over time. Overall, agar-based formulations yielded highly stable emulsions with small droplet sizes, showing no evidence of drastic creaming, or phase separation after 1 month of storage. Moreover, agar-based formulations were able to maintain ~ 100% conidial viability of T720 after 3 months of storage, and over 70% viability after 6 months. We anticipate that the results demonstrated herein will lead to a new generation of significantly improved formulations for practical biological control applications. Graphical abstract Key points • Various biopolymers were evaluated for improving the stability of Trichoderma conidia • Oil in water emulsions was prepared using cellulose nanocrystals and agar as interface stabilizers • Agar-based emulsions showed ~ 100% viability for encapsulated conidia after 3 months of storage