Rytioja Johanna, Hildén Kristiina, Di Falco Marcos, Zhou Miaomiao, Aguilar-Pontes Maria Victoria, Sietiö Outi-Maaria, Tsang Adrian, de Vries Ronald P, Mäkelä Miia R
Division of Microbiology and Biotechnology, Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland.
Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre & Fungal Molecular Physiology, Utrecht University, Utrecht, 3584, CT, The Netherlands.
Environ Microbiol. 2017 Mar;19(3):1237-1250. doi: 10.1111/1462-2920.13652. Epub 2017 Jan 23.
The ability to obtain carbon and energy is a major requirement to exist in any environment. For several ascomycete fungi, (post-)genomic analyses have shown that species that occupy a large variety of habitats possess a diverse enzymatic machinery, while species with a specific habitat have a more focused enzyme repertoire that is well-adapted to the prevailing substrate. White-rot basidiomycete fungi also live in a specific habitat, as they are found exclusively in wood. In this study, we evaluated how well the enzymatic machinery of the white-rot fungus Dichomitus squalens is tailored to degrade its natural wood substrate. The transcriptome and exoproteome of D. squalens were analyzed after cultivation on two natural substrates, aspen and spruce wood, and two non-woody substrates, wheat bran and cotton seed hulls. D. squalens produced ligninolytic enzymes mainly at the early time point of the wood cultures, indicating the need to degrade lignin to get access to wood polysaccharides. Surprisingly, the response of the fungus to the non-woody polysaccharides was nearly as good a match to the substrate composition as observed for the wood polysaccharides. This indicates that D. squalens has preserved its ability to efficiently degrade plant biomass types not present in its natural habitat.
获取碳和能量的能力是在任何环境中生存的主要需求。对于几种子囊菌而言，（后）基因组分析表明，占据多种栖息地的物种拥有多样的酶系，而具有特定栖息地的物种则拥有更具针对性的酶库，这些酶库能很好地适应主要底物。白腐担子菌也生活在特定的栖息地，因为它们仅存在于木材中。在本研究中，我们评估了白腐菌黄孢原毛平革菌（Dichomitus squalens）的酶系对降解其天然木材底物的适配程度。在两种天然底物（白杨木和云杉木）以及两种非木质底物（麦麸和棉籽壳）上培养后，分析了黄孢原毛平革菌的转录组和分泌蛋白质组。黄孢原毛平革菌主要在木材培养的早期产生木质素分解酶，这表明需要降解木质素来获取木材多糖。令人惊讶的是，该真菌对非木质多糖的反应与对木材多糖的反应几乎一样与底物组成相匹配。这表明黄孢原毛平革菌保留了有效降解其天然栖息地中不存在的植物生物质类型的能力。
