Search

Effective conservation strategies are needed to prevent further loss of biodiversity. This requires a comprehensive assessment of species' presence, distribution, and population sizes. Such assessments can be extremely challenging for species-rich taxa, like fungi, which are difficult to detect and identify. In recent years, metabarcoding applied to environmental samples has proven to be a promising method for fungal detection. However, its potential against traditional fruit body surveys in monitoring threatened fungal species has rarely been tested. Here, we utilized data on deadwood-inhabiting fungi from 569 deadwood objects across five sites in Central Europe to compare the effectiveness of fruit body surveys and metabarcoding (of low and high sampling intensity) in detecting threatened species. Across objects, sites, and per object, metabarcoding was more effective in detecting threatened species than fruit body surveys, regardless of sampling intensity. Eleven percent of all threatened species across all objects and sites could be detected by both methods, 70 % exclusively by metabarcoding and 18 % exclusively by fruit body surveys. The number of species detected by both methods on the same object was <4 %. Effects of high sampling intensity metabarcoding were stronger than low sampling intensity at object level. The effectiveness of the survey method was mainly independent of deadwood object characteristics. We suggest that metabarcoding is a valuable tool for threatened fungal species monitoring and conservation status assessments. However, for a comprehensive assessment, fruit body surveys are still needed, as this method detected a unique set of species and indicates the presence of vital fungal individuals.

Deadwood provides habitat for fungi and serves diverse ecological functions in forests. We already have profound knowledge of fungal assembly processes, physiological and enzymatic activities, and resulting physico-chemical changes during deadwood decay. However, in situ detection and identification methods, fungal origins, and a mechanistic understanding of the main lignocellulolytic enzymes are lacking. This study used metaproteomics to detect the main extracellular lignocellulolytic enzymes in 12 tree species in a temperate forest that have decomposed for 8 ½ years. Mainly white-rot (and few brown-rot) Basidiomycota were identified as the main wood decomposers, with Armillaria as the dominant genus; additionally, several soft-rot xylariaceous Ascomycota were identified. The key enzymes involved in lignocellulolysis included manganese peroxidase, peroxide-producing alcohol oxidases, laccase, diverse glycoside hydrolases (cellulase, glucosidase, xylanase), esterases, and lytic polysaccharide monooxygenases. The fungal community and enzyme composition differed among the 12 tree species. Ascomycota species were more prevalent in angiosperm logs than in gymnosperm logs. Regarding lignocellulolysis as a function, the extracellular enzyme toolbox acted simultaneously and was interrelated (e.g. peroxidases and peroxide-producing enzymes were strongly correlated), highly functionally redundant, and present in all logs. In summary, our in situ study provides comprehensive and detailed insight into the enzymatic machinery of wood-inhabiting fungi in temperate tree species. These findings will allow us to relate changes in environmental factors to lignocellulolysis as an ecosystem function in the future.

Enhanced nitrogen (N) deposition due to combustion of fossil fuels and agricultural fertilization is a global phenomenon which has severely altered carbon (C) and N cycling in temperate forest ecosystems in the northern hemisphere. Although deadwood holds a substantial amount of C in forest ecosystems and thus plays a crucial role in nutrient cycling, the effect of increased N deposition on microbial processes and communities, wood chemical traits and deadwood mass loss remains unclear. Here, we simulated high N deposition rates by adding reactive N in form of ammonium-nitrate (40 kg N ha−1 yr−1) to deadwood of 13 temperate tree species over nine years in a field experiment in Germany. Non-treated deadwood from the same logs served as control with background N deposition. Our results show that chronically elevated N levels alters deadwood mass loss alongside respiration, enzymatic activities and wood chemistry depending on tree clade and species. In gymnosperm deadwood, elevated N increased mass loss by +38 %, respiration by +37 % and increased laccase activity 12-fold alongside increases of white-rot fungal abundance +89 % (p = 0.03). Furthermore, we observed marginally significant (p = 0.06) shifts of bacterial communities in gymnosperm deadwood. In angiosperm deadwood, we did not detect consistent effects on mass loss, physico-chemical properties, extracellular enzymatic activity or changes in microbial communities except for changes in abundance of 10 fungal OTUs in seven tree species and 28 bacterial OTUs in 10 tree species. We conclude that N deposition alters decomposition processes exclusively in N limited gymnosperm deadwood in the long term by enhancing fungal activity as expressed by increases in respiration rate and extracellular enzyme activity with minor shifts in decomposing microbial communities. By contrast, deadwood of angiosperm tree species had higher N concentrations and mass loss as well as community composition did not respond to N addition.

Deadwood provides important ecological and biogeochemical functions in forest ecosystems. These functions rely on tree species-specific decay dynamics, but only few studies investigated how exogenous parameters affected the decay of deadwood at the regional scale. Here, we explore the influence of climate, soil traits and forest structure on decay dynamics and mass loss of logs of 13 tree species in 29 plots across three regions in Germany. This long-term experiment (BELongDead) comprises 1,066 logs of 9 angiosperms and 4 gymnosperms and covers a decay time of almost 10 years. Mass loss of logs was relatively high for the temperate climate with partly different half-lives ranging from 6 to 13 years (mean 8.9 ± 2.2 years). Diffuse-porous angiosperms lost 70 ± 13 % of their initial mass, followed by gymnosperms (49 ± 16 %) and ring-porous angiosperms (46 ± 12 %) within the study period. We applied three different mathematical models to fit mass loss in time and found that a linear model is most appropriate for 10 tree species. A sigmoidal model best described the mass loss of Fraxinus, Quercus and Pinus logs. A multivariate analysis revealed a significant effect of soil, temperature and precipitation on mass loss at the plot level. Mass loss increased with decreasing soil nutrient content, possibly as a result of enhanced bidirectional element translocations between nutrient-poor soils and logs by fungal hyphae. Temperature had a positive effect on mass loss, whereas increasing precipitation and soil moisture were negatively related to mass loss. The region with warmer, moderately humid climate and unfavourable soil properties led to overall higher mass loss (66 ± 4 %) whereas the other two regions were indifferent (both 57 ± 3 %). Forest structure, including canopy cover, share of coniferous trees and the stock of deadwood in the vici

Lipid mediators, such as epoxidized or hydroxylated eicosanoids (EETs, HETEs) of arachidonic acid (AA), are important signaling molecules and play diverse roles at different physiological and pathophysiological levels. The EETs and HETEs formed by the cytochrome P450 enzymes are still not fully explored, but show interesting anti-inflammatory properties, which make them attractive as potential therapeutic target or even as therapeutic agents. Conventional methods of chemical synthesis require several steps and complex separation techniques and lead only to low yields. Using the newly discovered unspecific peroxygenase TanUPO from the ascomycetous fungus Truncatella angustata, 90% regioselective conversion of AA to 14,15-EET could be achieved. Selective conversion of AA to 18-HETE, 19-HETE as well as to 11,12-EET and 14,15-EET was also demonstrated with known peroxygenases, i.e., AaeUPO, CraUPO, MroUPO, MweUPO and CglUPO. The metabolites were confirmed by HPLC-ELSD, MS1 and MS2 spectrometry as well as by comparing their analytical data with authentic standards. Protein structure simulations of TanUPO provided insights into its substrate access channel and give an explanation for the selective oxyfunctionalization of AA. The present study expands the scope of UPOs as they can now be used for selective syntheses of AA metabolites that serve as reference material for diagnostics, for structure-function elucidation as well as for therapeutic and pharmacological purposes.

Forestry in Europe changed the tree species composition and reduced dead-wood amount and heterogeneity, and therefore negatively affected saproxylic diversity. Efficient conservation requires knowledge about the importance of the relevant diversity drivers across taxa. We examined the relative importance of space vs. host for saproxylic diversity at a spatial extend of 600 km in Germany. Further, we disentangled effects of among regions, forest stands, host clades, and tree species on saproxylic diversity. This allows inferences for spatial- and host tree-related conservation strategies. Beetle, fungal sporocarp, molecular-derived fungal, and bacterial communities were studied in a large nested dead-wood experiment comprising 11 tree species. We used multiplicative diversity partitioning to assess the diversity of rare, typical, and dominant species. The beta-diversity of beetles and fungal sporocarps was equally explained by space and host, but that of molecular fungi and bacteria mainly by the host. Across taxa, beta-diversity was higher among forest stands than among regions. However, for beetles and fungal sporocarps, differences among regions were also important. Host tree clade and host tree species were important for beetle and host clade for fungal sporocarp beta-diversity. Host tree species was more important than host clade for the beta-diversity of molecular fungi and bacteria. The divergent response of different taxa to space and host calls into question the use of a simple spatially-centered or host-centered strategy. Instead, a high dead-wood tree species diversity on a broad spatial coverage at the national scale in temperate European forests is necessary to maintain rare and abundant species.

Deadwood provides an important carbon source in forests and wooded ecosystems and, accordingly, forest management strategies discuss the enrichment of deadwood amount and diversity by different tree species. To investigate the decomposition processes of enriched deadwood, we simultaneously placed 3,669 size-standardized and gamma sterilized wood specimens of 13 tree species (Populus tremula, Tilia cordata, Prunus avium, Betula pendula, Carpinus betulus, Fraxinus excelsior, Quercus robur, Fagus sylvatica, Acer platanoides, Larix decidua, Pinus sylvestris, Picea abies, and Pseudotsuga menziesii) at a total of 300 forest and grassland plots in three regions in Germany covering large gradients of management intensity and environmental conditions. After 1 year, mass loss was calculated and its relationship with wood traits and environmental conditions was assessed to determine the most important factors. Mass loss was overall higher in forest compared to grassland habitats, with wood traits as the most important driver, followed by region and environmental factors related to microclimate. However, management intensity was less relevant to explain the mass loss in both habitats. Our results suggest that decomposition of enriched deadwood, even after removal of endophytes, is influenced by the same drivers (positively by moisture and abundance of macronutrients, negatively by lignin and phenol concentration) as naturally occurring wood. Furthermore, due to the immense and standardized experimental setting, our study contributes to a better understanding of the important drivers of mass loss in different tree species and thus provides the basis for predictions of the carbon cycle in a changing world.

Background: Fungal DyP-type peroxidases have so far been described exclusively for basidiomycetes. Moreover, peroxidases from ascomycetes that oxidize Mn2+ ions are yet not known. Methods: We describe here the physicochemical, biocatalytic, and molecular characterization of a DyP-type peroxidase (DyP, EC 1.11.1.19) from an ascomycetous fungus. Results: The enzyme oxidizes classic peroxidase substrates such as 2,6-DMP but also veratryl alcohol and notably Mn2+ to Mn3+ ions, suggesting a physiological function of this DyP in lignin modification. The KM value (49 µM) indicates that Mn2+ ions bind with high affinity to the XgrDyP protein but their subsequent oxidation into reactive Mn3+ proceeds with moderate efficiency compared to MnPs and VPs. Mn2+ oxidation was most effective at an acidic pH (between 4.0 and 5.0) and a hypothetical surface exposed an Mn2+ binding site comprising three acidic amino acids (two aspartates and one glutamate) could be localized within the hypothetical XgrDyP structure. The oxidation of Mn2+ ions is seemingly supported by four aromatic amino acids that mediate an electron transfer from the surface to the heme center. Conclusions: Our findings shed new light on the possible involvement of DyP-type peroxidases in lignocellulose degradation, especially by fungi that lack prototypical ligninolytic class II peroxidases

Fungi and prokaryotes are dominant colonizers of wood and mediate its decomposition. Much progress has been achieved to unravel these communities and link them to specific wood properties. However, comparative studies considering both groups of organisms and assessing their relationships to wood resources are largely missing. Bipartite interaction networks provide an opportunity to investigate this colonizer-resource relationship more in detail and aim to directly compare results between different biotic groups. The main questions were as follows. Are network structures reflecting the trophic relationship between fungal and prokaryotic colonizers and their resources? If so, do they reflect the critical role of these groups, especially that of fungi, during decomposition? We used amplicon sequencing data to analyze fungal and prokaryotic interaction networks from deadwood of 13 temperate tree species at an early to middle stage of decomposition. Several diversity- and specialization-related indices were determined and the observed network structures were related to intrinsic wood traits. We hypothesized nonrandom bipartite networks for both groups and a higher degree of specialization for fungi, as they are the key players in wood decomposition. The results reveal highly modular and specialized interaction networks for both groups of organisms, demonstrating that many fungi and prokaryotes are resource-specific colonizers. However, as the level of specialization of fungi significantly surpassed that of prokaryotes, our findings reflect the strong association between fungi and their host. Our novel approach shows that the application of bipartite interaction networks is a useful tool to explore, quantify, and compare the deadwood-colonizers relationship based on sequencing data.

Los Agaricomycetes han desarrollado complejas maquinarias enzimáticas que les permiten descomponer los diferentes polímeros vegetales, incluida la lignina. Entre ellos, los Agaricales saprótrofos se caracterizan por su diversidad de hábitats y estilos de vida. El análisis de 52 genomas de Agaricomycetes aquí realizado revela que los Agaricales poseen una gran diversidad de enzimas hidrolíticas y oxidativas para la descomposición de la lignocelulosa. En base a las familias de genes con mayor velocidad evolutiva (dominios de unión a celulosa, glicosil hidrolasa GH43, monooxigenasas líticas de polisacáridos, peroxidasas ligninolíticas, enzimas de la superfamilia de glucosa-metanol-colina oxidasas/deshidrogenasas, lacasas y peroxigenasas), reconstruimos los estilos de vida de los ancestros que dieron lugar a los actuales Agaricomycetes degradadores de lignocelulosa. Los cambios en el conjunto de herramientas enzimáticas de los Agaricales ancestrales se correlacionaron con la evolución de su capacidad para crecer no solo sobre madera, sino también sobre hojarasca de bosques y madera en descomposición, siendo los descomponedores de la hojarasca de praderas el grupo ecofisiológico más reciente. En este contexto, las anteriores familias de enzimas se analizaron en relación con la diversidad de estilos de vida. Las peroxidasas aparecen como un componente central del set enzimático de los Agaricomycetes saprotrófos, consistente con su papel esencial en la degradación de la lignina y sus altas tasas evolutivas. Esto incluye no solo expansiones/pérdidas de genes de peroxidasas, sino también la presencia generalizada en Agaricales de nuevos tipos de peroxidasas que no se encuentran en Polyporales degradadores de madera, y en otros órdenes de Agaricomycetes.

Qualitätsstandards (QS) sind messbare Konstrukte, die helfen sollen, Versorgungslücken quantitativ zu erfassen, um langfristig die Versorgungsqualität zu verbessern. Die Assessment of SpondyloArthritis International Society (ASAS) hat kürzlich erstmals internationale QS für das Management von Patient*innen mit axialer Spondyloarthritis (axSpA) konsentiert und veröffentlicht. Die Deutsche Gesellschaft für Rheumatologie (DGRh) hat daraufhin beschlossen, diese Standards durch eine Gruppe von Expert*innen aus unterschiedlichen Versorgungsbereichen zu übersetzen, zu prüfen und ggf. zu übernehmen. Vor diesem Hintergrund wurden erstmals nationale QS für das Management von Patient*innen mit axSpA für Deutschland entwickelt. Hierbei wurde v. a. auf Machbarkeit und Praxisrelevanz geachtet. Letztlich wurden 9 QS definiert, mit denen die Qualität der Versorgung in Deutschland gemessen und verbessert werden kann bzw. soll., Quality standards (QS) are measurable constructs designed to quantify gaps in care and subsequently to improve quality of care. The Assessment of SpondyloArthritis International Society (ASAS) recently generated and published international QS for the management of patients with axial spondyloarthritis (axSpA) for the first time. The German Society of Rheumatology (DGRh) then decided to translate, review and possibly adopt these standards by a group of experts from different care settings. Against this background, national QS for the management of patients with axSpA for Germany were developed for the first time. The main focus was on feasibility and practical relevance. Ultimately, nine QS were defined with which the quality of care in Germany can and should be measured and improved.