Evaluation of the interspecific competitive ability of the bioincising fungus Physisporinus vitreus

Abstract

A hierarchical set of assays were used to evaluate the interspecific competitive ability of the bioincising fungus Physiporinus vitreus (response species). The competitiveness and growth mode of P. vitreus against a range of blue stain fungi and Trichoderma species (challenge species) was investigated in dual culture tests (a) and a spatially heterogeneous system of tessellation agar (b) on different media. In addition, the robustness of the bioincising process against biotic influences was determined by controlled interaction tests with different inocula of the challenge species (colony-forming units: 10(2), 10(4), 10(6) ml(-1)) on Norway spruce (Picea abies Karst.) heartwood. The results of the dual culture and tessellation agar tests revealed a significant (P ≤ 0.001) antagonistic potential (lethal effect) of the T. atroviride strain (15603.1), whereas no or only a slight effect of the blue stain fungi on P. vitreus was detectable. The interaction tests on Norway spruce heartwood confirmed that an increase in inoculum size of the challenge fungi correlated with an increased negative effect (Spearman's rho coefficient (ρ) = -0.521). Among the challenge species, T-15603.1 revealed the most negative effect on the homogeneous development of P. vitreus on wood and thus on the outcome of the bioincising process. To improve the uniformity of colonization and to reduce the rate of contamination, the incubation of wood in a sealed system (bioreactor) after sterilization is suggested.

Physisporinus vitreus: a versatile white rot fungus for engineering value-added wood products

“…a decisive competitor of P. vitreus. Schubert and Schwarze (2011) also showed that Trichoderma spp. have by far the most significant negative effect on the performance of P. vitreus, even with a low inoculum potential.…”

Effects of different incising pretreatments in improving permeability in two refractory wood species

“…In this study, P. vitreus was more active in larch sapwood than in spruce sapwood samples, with polyurethane sealing endgrain and longitudinal surfaces. It is known that P. vitreus used in the bioincising process selectively delignifies the wood and prefers mainly bordered pits primarily containing pectin in the wood (Schwarze 2007; Lehringer et al 2009aLehringer et al , 2010Schubert and Schwarze 2011;Fuhr et al 2013;Schubert et al 2013;Gilani and Schwarze 2014). Physisporinus vitreus likely decomposes the aspirated pits in larch sapwood more than in spruce sapwood.…”

“…This first pretreatment was bioincising. The biotechnological method of bioincising increases the uptake of impregnation in low-permeability wood species such as spruce by incubating Physisporinus vitreus, a white rot fungus that belongs to the Basidiomycetes class (Lehringer et al 2009b;Lehringer et al 2010;Schubert and Schwarze 2011). The second pretreatment was mechanical incising, where small slits are opened in the wood by running toothed rollers parallel to the fibers (Perrin 1978;Winandy et al 1995;Morris 1995).…”