Dual-fungi competition and its influence on wood degradation

Abstract

There are different fungi colonized on wood in nature, and the competition among them varies with wood species. In order to understand the fungal competition on different substrates and its influence on degradation of both softwood and hardwood, four typical wood-decaying fungi (P. chrysosporium, T. versicolor, P. placenta, G. trabeum) were grouped in pairs to investigate the dual-fungi interactions on potato dextrose agar (PDA) and two wood species [Cathay poplar (Populus cathayana Rehd.) and Southern pine (Pinus spp.)], the colonization behavior was recorded, and the mass losses (MLs), microscopic structure and chemical composition change of decayed wood samples were investigated. Three different interaction outcomes were observed in dual culturing of fungi, namely, partial replacement, complete replacement, and deadlock. Deadlock and partial replacement are common outcomes on PDA, while complete replacement is dominant on wood substrate. Wood degradation is highly related with the dominant fungi, wood species, and the colonization order of fungi. Among all dual cultures, T. versicolor-G. trabeum combination showed the strongest degradation ability on poplar wood, while G. trabeum-T. versicolor showed the highest ML on pine wood. Compared with monocultures, the higher ML values of most dual cultures indicated that the interaction between dual fungi can accelerate wood degradation. The results can benefit the understanding of the decay behavior on wood and also provide some thoughts on improving the microbial pretreatment efficiency of biomass.