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1.
Microb Ecol ; 78(3): 725-736, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30761423

RESUMO

The home-field advantage (HFA) hypothesis has been used intensively to study leaf litter decomposition in various ecosystems. However, the HFA in woody substrates is still unexplored. Here, we reanalyzed and integrated existing datasets on various groups of microorganisms collected from natural deadwood of two temperate trees, Fagus sylvatica and Picea abies, from forests in which one or other of these species dominates but where both are present. Our aims were (i) to test the HFA hypothesis on wood decomposition rates of these two temperate tree species, and (ii) to investigate if HFA hypothesis can be explained by diversity and community composition of bacteria and in detail N-fixing bacteria (as determined by molecular 16S rRNA and nifH gene amplification) and fungi (as determined by molecular ITS rRNA amplification and sporocarp surveys). Our results showed that wood decomposition rates were accelerated at "home" versus "away" by 38.19% ± 20.04% (mean ± SE). We detected strong changes in fungal richness (increase 36-50%) and community composition (RANOSIM = 0.52-0.60, P < 0.05) according to HFA hypothesis. The changes of fungi were much stronger than for total bacteria and nitrogen fixing for both at richness and community composition levels. In conclusion, our results support the HFA hypothesis in deadwood: decomposition rate is accelerated at home due to specialization of fungal communities produced by the plant community above them. Furthermore, the higher richness of fungal sporocarps and nitrogen-fixing bacteria (nifH) may stimulate or at least stabilize wood decomposition rates at "home" versus "away."


Assuntos
Fagus/microbiologia , Fungos/isolamento & purificação , Fungos/metabolismo , Micobioma , Picea/microbiologia , Madeira/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biodegradação Ambiental , DNA Fúngico/genética , Fungos/classificação , Fungos/genética , Nitrogênio/metabolismo , RNA Ribossômico 16S/genética , Árvores/microbiologia
2.
Conserv Biol ; 33(3): 716-724, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30350883

RESUMO

Next-generation sequencing (NGS) has significantly increased knowledge of microbial communities and their distribution. However, it is still not common to apply NGS technology to microbial conservation. We sought to use NGS technologies to evaluate conservation strategies for wood-inhabiting fungi. Evaluating a deadwood experiment 3 years after it was established, we specifically examined which tree species combinations promoted the highest richness of wood-inhabiting fungi. Deadwood enrichment was an effective strategy and logs of 6 tree species, either those with the highest wood-inhabiting fungal α and γ diversity or those with the highest ß diversity, maintained >1,000 operational taxonomic units (OTUs) spread over a wide range of taxonomic groups. In comparison, a conservation strategy based only on the results of sporocarp surveys yielded 591 OTUs. This result highlights the need to use NGS approaches to inform microbial conservation strategies. We also determined that 5 tree species with the highest saproxylic beetle γ diversity simultaneously conserved wood-inhabiting fungi. Apart from deadwood volume, we suggest data on deadwood quality and species also be included as indicators, especially for wood-inhabiting fungal diversity, and incorporated quickly in forest assessment and monitoring systems in Central Europe.


Aplicación de Tecnologías de Secuenciación de Nueva Generación a la Conservación de Hongos Habitantes de Madera Resumen La secuenciación de nueva generación (NGS, en inglés) ha incrementado significativamente el conocimiento que tenemos de las comunidades microbianas y su distribución. Sin embargo, aún no es común aplicar la tecnología NGS a la conservación de microbios. Buscamos usar estas tecnologías para evaluar las estrategias de conservación que hay para los hongos que habitan la madera. Durante la evaluación de un experimento con madera muerta tres años después de que fue establecido, examinamos específicamente cuáles combinaciones de especies de árbol promovían la mayor riqueza de hongos que habitan la madera. El enriquecimiento de madera muerta fue una estrategia efectiva y los troncos de seis especies de árboles, ya fueran aquellas con la diversidad α y la γ más altas de hongos habitantes de madera o aquellas con la diversidad ß más alta, mantuvieron a >1000 unidades taxonómicas operativas (OTUs, en inglés) distribuidas en una gama amplia de grupos taxonómicos. En comparación, una estrategia de conservación basada sólo en los resultados de los censos de esporocarpos dio como resultado 591 OTUs. Este resultado resalta la necesidad de utilizar estrategias de NGS para informar a las estrategias de conservación de microbios. También determinamos que cinco especies de árboles con la diversidad γ más alta de escarabajos saproxílicos conservaron simultáneamente a los hongos que habitan la madera. Además del volumen de madera muerta, sugerimos que también se incluyan como indicadores los datos sobre la calidad de la madera muerta y las especies, especialmente para la diversidad de hongos que habitan la madera, y que se incorpore rápidamente a los sistemas de evaluación y monitoreo de bosques en Europa central.


Assuntos
Biodiversidade , Madeira , Animais , Conservação dos Recursos Naturais , Europa (Continente) , Fungos , Sequenciamento de Nucleotídeos em Larga Escala , Árvores
3.
Environ Microbiol ; 20(5): 1693-1710, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29473288

RESUMO

Nitrogen deposition can strongly affect biodiversity, but its specific effects on terrestrial microbial communities and their roles for ecosystem functions and processes are still unclear. Here, we investigated the impacts of N deposition on wood-inhabiting fungi (WIF) and their related ecological functions and processes in a highly N-limited deadwood habitat. Based on high-throughput sequencing, enzymatic activity assay and measurements of wood decomposition rates, we show that N addition has no significant effect on the overall WIF community composition or on related ecosystem functions and processes in this habitat. Nevertheless, we detected several switches in presence/absence (gain/loss) of wood-inhabiting fungal OTUs due to the effect of N addition. The responses of WIF differed from previous studies carried out with fungi living in soil and leaf-litter, which represent less N-limited fungal habitats. Our results suggest that adaptation at different levels of organization and functional redundancy may explain this buffered response and the resistant microbial-mediated ecosystem function and processes against N deposition in highly N-limited habitats.


Assuntos
Biodiversidade , Fungos/efeitos dos fármacos , Fungos/fisiologia , Micobioma , Nitrogênio/farmacologia , Madeira/microbiologia , Aclimatação , Fungos/classificação , Microbiota , Nitrogênio/análise , Folhas de Planta/microbiologia , Microbiologia do Solo
4.
Mol Ecol ; 25(16): 4059-74, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27357176

RESUMO

Microorganisms play a crucial role in the biological decomposition of plant litter in terrestrial ecosystems. Due to the permanently changing litter quality during decomposition, studies of both fungi and bacteria at a fine taxonomic resolution are required during the whole process. Here we investigated microbial community succession in decomposing leaf litter of temperate beech forest using pyrotag sequencing of the bacterial 16S and the fungal internal transcribed spacer (ITS) rRNA genes. Our results reveal that both communities underwent rapid changes. Proteobacteria, Actinobacteria and Bacteroidetes dominated over the entire study period, but their taxonomic composition and abundances changed markedly among sampling dates. The fungal community also changed dynamically as decomposition progressed, with ascomycete fungi being increasingly replaced by basidiomycetes. We found a consistent and highly significant correlation between bacterial richness and fungal richness (R = 0.76, P < 0.001) and community structure (RM antel  = 0.85, P < 0.001), providing evidence of coupled dynamics in the fungal and bacterial communities. A network analysis highlighted nonrandom co-occurrences among bacterial and fungal taxa as well as a shift in the cross-kingdom co-occurrence pattern of their communities from the early to the later stages of decomposition. During this process, macronutrients, micronutrients, C:N ratio and pH were significantly correlated with the fungal and bacterial communities, while bacterial richness positively correlated with three hydrolytic enzymes important for C, N and P acquisition. Overall, we provide evidence that the complex litter decay is the result of a dynamic cross-kingdom functional succession.


Assuntos
Bactérias/classificação , Florestas , Fungos/classificação , Folhas de Planta/microbiologia , Microbiologia do Solo , DNA Espaçador Ribossômico/genética , RNA Ribossômico 16S/genética
5.
Bioconjug Chem ; 27(2): 319-28, 2016 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-26172432

RESUMO

Multimodal nanoparticulate materials are described, offering magnetic, radionuclide, and fluorescent imaging capabilities to exploit the complementary advantages of magnetic resonance imaging (MRI), positron emission tomography/single-photon emission commuted tomography (PET/SPECT), and optical imaging. They comprise Fe3O4@NaYF4 core/shell nanoparticles (NPs) with different cation dopants in the shell or core, including Co0.16Fe2.84O4@NaYF4(Yb, Er) and Fe3O4@NaYF4(Yb, Tm). These NPs are stabilized by bisphosphonate polyethylene glycol conjugates (BP-PEG), and then show a high transverse relaxivity (r2) up to 326 mM(-1) s(-1) at 3T, a high affinity to [(18)F]-fluoride or radiometal-bisphosphonate conjugates (e.g., (64)Cu and (99m)Tc), and fluorescent emissions from 500 to 800 nm under excitation at 980 nm. The biodistribution of intravenously administered particles determined by PET/MR imaging suggests that negatively charged Co0.16Fe2.84O4@NaYF4(Yb, Er)-BP-PEG (10K) NPs cleared from the blood pool more slowly than positively charged NPs Fe3O4@NaYF4(Yb, Tm)-BP-PEG (2K). Preliminary results in sentinel lymph node imaging in mice indicate the advantages of multimodal imaging.


Assuntos
Óxido Ferroso-Férrico/química , Fluoretos/química , Imageamento por Ressonância Magnética/métodos , Nanopartículas/química , Imagem Óptica/métodos , Tomografia por Emissão de Pósitrons/métodos , Ítrio/química , Animais , Difosfonatos/química , Difosfonatos/farmacocinética , Óxido Ferroso-Férrico/farmacocinética , Fluoretos/farmacocinética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Nus , Imagem Multimodal/métodos , Polietilenoglicóis/química , Polietilenoglicóis/farmacocinética , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Ítrio/farmacocinética
6.
J Nat Prod ; 79(4): 929-38, 2016 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-26953507

RESUMO

The Chilean Sepedonium aff. chalcipori strain KSH 883, isolated from the endemic Boletus loyo Philippi, was studied in a polythetic approach based on chemical, molecular, and biological data. A taxonomic study of the strain using molecular data of the ITS, EF1-α, and RPB2 barcoding genes confirmed the position of the isolated strain within the S. chalcipori clade, but also suggested the separation of this clade into three different species. Two new linear 15-residue peptaibols, named chilenopeptins A (1) and B (2), together with the known peptaibols tylopeptins A (3) and B (4) were isolated from the semisolid culture of strain KSH 883. The structures of 1 and 2 were elucidated on the basis of HRESIMS(n) experiments in conjunction with comprehensive 1D and 2D NMR analysis. Thus, the sequence of chilenopeptin A (1) was identified as Ac-Aib(1)-Ser(2)-Trp(3)-Aib(4)-Pro(5)-Leu(6)-Aib(7)-Aib(8)-Gln(9)-Aib(10)-Aib(11)-Gln(12)-Aib(13)-Leu(14)-Pheol(15), while chilenopeptin B (2) differs from 1 by the replacement of Trp(3) by Phe(3). Additionally, the total synthesis of 1 and 2 was accomplished by a solid-phase approach, confirming the absolute configuration of all chiral amino acids as l. Both the chilenopeptins (1 and 2) and tylopeptins (3 and 4) were evaluated for their potential to inhibit the growth of phytopathogenic organisms.


Assuntos
Antibacterianos/isolamento & purificação , Peptaibols/isolamento & purificação , Sequência de Aminoácidos , Antibacterianos/química , Antibacterianos/farmacologia , Basidiomycota/metabolismo , Chile , Hypocreales/química , Estrutura Molecular , Peptaibols/química , Peptaibols/farmacologia , Peptídeos/química , Peptídeos/isolamento & purificação , Peptídeos/farmacologia , Trichoderma/química
7.
Microb Ecol ; 70(2): 390-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25687125

RESUMO

Soil fungi play an essential role in the decomposition of plant-derived organic material entering soils. The quality and quantity of organic compounds vary seasonally as well as with soil depth. To elucidate how these resources affect fungal communities in an arable soil, a field experiment was set up with two plant species, maize and wheat. Resource availability was experimentally manipulated by maize litter input on one half of these maize and wheat plots after harvest in autumn. Fungal biomass was determined by ergosterol quantification, and community structure was investigated by fungal automated ribosomal intergenic spacer analysis (F-ARISA). An annual cycle was assessed across a depth gradient, distinguishing three soil habitats: the plough layer, rooted soil below the plough layer, and deeper root-free soil. Fungal communities appeared highly dynamic and varied according to soil depth and plant resources. In the plough layer, the availability of litter played a dominant role in shaping fungal communities, whereas in the rooted layer below, community structure and biomass mainly differed between plant species. This plant effect was also extended into the root-free soil at a depth of 70 cm. In winter, the availability of litter also affected fungal communities in deeper soil layers, suggesting vertical transport processes under fallow conditions. These distinct resource effects indicate diverse ecological niches along the soil profile, comprising specific fungal metacommunities. The recorded responses to both living plants and litter point to a central role of fungi in connecting primary production and decomposition within the plant-soil system.


Assuntos
Fungos/fisiologia , Microbiologia do Solo , Biomassa , Ecossistema , Fungos/isolamento & purificação , Fungos/metabolismo
8.
Microb Ecol ; 69(4): 905-13, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25749938

RESUMO

Forest management practices (FMPs) significantly influence important ecological processes and services in Central European forests, such as leaf litter decomposition and nutrient cycling. Changes in leaf litter diversity, and thus, its quality as well as microbial community structure and function induced by different FMPs were hypothesized to be the main drivers causing shifts in decomposition rates and nutrient release in managed forests. In a litterbag experiment lasting 473 days, we aimed to investigate the effects of FMPs (even-aged timber management, selective logging and unmanaged) on bacterial and fungal communities involved in leaf litter degradation over time. Our results showed that microbial communities in leaf litter were strongly influenced by both FMPs and sampling date. The results from nonmetric multidimensional scaling (NMDS) ordination revealed distinct patterns of bacterial and fungal successions over time in leaf litter. We demonstrated that FMPs and sampling dates can influence a range of factors, including leaf litter quality, microbial macronutrients, and pH, which significantly correlate with microbial community successions.


Assuntos
Bactérias/genética , Agricultura Florestal/métodos , Florestas , Fungos/genética , Folhas de Planta/química , Microbiologia do Solo , Bactérias/metabolismo , DNA Intergênico/genética , DNA Intergênico/metabolismo , DNA Espaçador Ribossômico/genética , DNA Espaçador Ribossômico/metabolismo , Fungos/metabolismo , Alemanha
9.
J Environ Manage ; 139: 109-19, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24681650

RESUMO

The impact of changes within a single land-use category or land-use intensity on microbial communities is poorly understood, especially with respect to fungi. Here we assessed how forest management regimes and a change in forest type affect the richness and community structure of wood-inhabiting fungi across Germany. We used molecular methods based on the length polymorphism of the internal transcribed spacers and the 5.8S rRNA gene to assess fungal operational taxonomic units (OTUs). A cloning/sequencing approach was used to identify taxonomic affinities of the fungal OTUs. Overall, 20-24% and 25-27% of native fungal OTUs from forest reserves and semi-natural forests became undetectable or were lost in managed and converted forests, respectively. Fungal richness was significantly reduced during a regeneration phase in age-class beech forests with a high level of wood extraction (P = 0.017), whereas fungal community structures were not significantly affected. Conversion of forests from native, deciduous to coniferous species caused significant changes in the fungal community structure (R = 0.64-0.66, P = 0.0001) and could reduce fungal richness (P < 0.05) which may depend on which coniferous species was introduced. Our results showed that Ascocoryne cylichnium, Armillaria sp., Exophiala moniliae, Hyphodontia subalutacea and Fomes fomentarius, all known for wood-decaying abilities were strongly reduced in their abundances when forests were converted from beech to coniferous. We conclude that changes within a single land-use category can be regarded as a major threat to fungal diversity in temperate forest ecosystems.


Assuntos
Fungos/classificação , Madeira/microbiologia , Biodiversidade , Agricultura Florestal/métodos , Florestas , Fungos/genética , Alemanha , RNA Fúngico , RNA Ribossômico
10.
Microb Ecol ; 63(2): 295-303, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21833540

RESUMO

Interactions between mushrooms, yeasts, and parasitic fungi are probably common in nature, but are rarely described. Bolete fruiting bodies are associated with a broad spectrum of microorganisms including yeasts, and they are commonly infected with filamentous mycoparasites of the genus Sepedonium (teleomorph Hypomyces). We report the isolation of 17 yeast strains from Paxillus and Xerocomus, 16 of which were obtained from the surface tissue, the primary site of Sepedonium infection. Phylogenetic analyses with the D1/D2 region of the 28S ribosomal gene and the internal transcribed spacers placed the yeasts as Rhodotorula, Rhodosporidium, and Mastigobasidium from the Pucciniomycotina, Cryptococcus, Cystofilobasidium, Holtermanniella, and Trichosporon from the Agaricomycotina, and Kluyveromyces from the Saccharomycotina including the first isolation of Rhodotorula graminis from Europe. To investigate the influence of the yeast strains on the mycoparasite and the host fungus, in vitro assays were conducted with Sepedonium chrysospermum and Paxillus involutus. Both S. chrysospermum growth inhibitory and stimulating yeast strains were detected among the isolates. The number of S. chrysospermum inhibitory yeast strains increased and the number of S. chrysospermum stimulatory yeast strains decreased in the presence of P. involutus in co-cultures. Low nutrient levels in the culture medium also led to an increased number of S. chrysospermum inhibitory yeast strains and ten yeasts inhibited the mycoparasite in spatial separation by a crosswall. Six yeast strains inhibited P. involutus in dual culture, and the inhibitory P. involutus yeast interactions increased to nine in the presence of S. chrysospermum. Our results suggest that the bolete-associated yeasts influence the growth of the mycoparasitic fungus, which may affect the health of the fruiting bodies.


Assuntos
Basidiomycota/fisiologia , Hypocreales/crescimento & desenvolvimento , Leveduras/genética , Leveduras/isolamento & purificação , Ascomicetos/classificação , Ascomicetos/genética , Ascomicetos/isolamento & purificação , Ascomicetos/fisiologia , Basidiomycota/classificação , Basidiomycota/genética , Basidiomycota/isolamento & purificação , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Ecossistema , Carpóforos/classificação , Carpóforos/genética , Carpóforos/fisiologia , Alemanha , Hypocreales/fisiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Ribossômico 28S/genética , Especificidade da Espécie , Leveduras/classificação , Leveduras/fisiologia
11.
Front Microbiol ; 9: 2120, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30294306

RESUMO

Despite the important role of wood-inhabiting fungi (WIF) in deadwood decomposition, our knowledge of the factors shaping the dynamics of their species richness and community composition is scarce. This is due to limitations regarding the resolution of classical methods used for characterizing WIF communities and to a lack of well-replicated long-term experiments with sufficient numbers of tree species. Here, we used a large scale experiment with logs of 11 tree species at an early stage of decomposition, distributed across three regions of Germany, to identify the factors shaping WIF community composition and Operational Taxonomic Unit (OTU) richness using next generation sequencing. We found that tree species identity was the most significant factor, corresponding to (P < 0.001) and explaining 10% (representing 48% of the explainable variance) of the overall WIF community composition. The next important group of variables were wood-physicochemical properties, of which wood pH was the only factor that consistently corresponded to WIF community composition. For overall WIF richness patterns, we found that approximately 20% of the total variance was explained by wood N content, location, tree species identity and wood density. It is noteworthy that the importance of determinants of WIF community composition and richness appeared to depend greatly on tree species group (broadleaved vs. coniferous) and it differed between the fungal phyla Ascomycota and Basidiomycota.

12.
BMC Res Notes ; 10(1): 95, 2017 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-28193243

RESUMO

Since it first launched in 2008, BMC Research Notes has been a place where researchers can publish short notes and observations, research outputs which are useful for the community but which can end up hidden in the lab notebook or as a footnote in a dataset. In order to re-affirm the importance of publishing these kinds of outputs, the journal is renewing its focus on publishing note articles as well as other potentially dark data such as short null results. Publishing these articles is useful for many researchers, therefore we are also expanding the scope to all scientific and clinical disciplines including health sciences, life sciences, physical sciences, mathematics and all engineering disciplines. With this refocusing of BMC Research Notes back to its original vision, BioMed Central is offering a home for short communications to make dark data and single observations widely available to the global research community.


Assuntos
Pesquisa Biomédica/métodos , Políticas Editoriais , Publicações Periódicas como Assunto/normas , Projetos de Pesquisa
13.
ISME J ; 2017 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-29087376

RESUMO

Wood-inhabiting fungi have essential roles in the regulation of carbon stocks and nutrient cycling in forest ecosystems. However, knowledge pertaining to wood-inhabiting fungi is only fragmentary and controversial. Here we established a large-scale deadwood experiment with 11 tree species to investigate diversity and tree species preferences of wood-inhabiting fungi using next-generation sequencing. Our results contradict existing knowledge based on sporocarp surveys and challenge current views on their distribution and diversity in temperate forests. Analyzing α-, ß- and γ-diversity, we show that diverse fungi colonize deadwood at different spatial scales. Specifically, coniferous species have higher α- and γ-diversity than the majority of analyzed broadleaf species, but two broadleaf species showed the highest ß-diversity. Surprisingly, we found nonrandom co-occurrence (P<0.001) and strong tree species preferences of wood-inhabiting fungi, especially in broadleaf trees (P<0.01). Our results indicate that the saprotrophic fungal community is more specific to tree species than previously thought.The ISME Journal advance online publication, 31 October 2017; doi:10.1038/ismej.2017.177.

14.
PLoS One ; 11(2): e0148130, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26840453

RESUMO

Fungi are prominent drivers of ecological processes in soils, so that fungal communities across different soil ecosystems have been well investigated. However, for arable soils taxonomically resolved fine-scale studies including vertical itemization of fungal communities are still missing. Here, we combined a cloning/Sanger sequencing approach of the ITS/LSU region as marker for general fungi and of the partial SSU region for arbuscular mycorrhizal fungi (AMF) to characterize the microbiome in different maize soil habitats. Four compartments were analyzed over two annual cycles 2009 and 2010: a) ploughed soil in 0-10 cm, b) rooted soil in 40-50 cm, c) root-free soil in 60-70 cm soil depth and d) maize roots. Ascomycota was the most dominant phylum across all compartments. Fungal communities including yeasts and AMF differed strongly between compartments. Inter alia, Tetracladium, the overall largest MOTU (molecular operational taxonomic unit), occurred in all compartments, whereas Trichosporon dominated all soil compartments. Sequences belonging to unclassified Helotiales were forming the most abundant MOTUs exclusively present in roots. This study gives new insights on spatial distribution of fungi and helps to link fungal communities to specific ecological properties such as varying resources, which characterize particular niches of the heterogeneous soil environment.


Assuntos
Fungos/fisiologia , Microbiota/fisiologia , Microbiologia do Solo , Solo
15.
PLoS One ; 10(11): e0143566, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26599572

RESUMO

Freshly cut beech deadwood was enriched in the canopy and on the ground in three cultural landscapes in Germany (Swabian Alb, Hainich-Dün, Schorfheide-Chorin) in order to analyse the diversity, distribution and interaction of wood-inhabiting fungi and beetles. After two years of wood decay 83 MOTUs (Molecular Operational Taxonomic Units) from 28 wood samples were identified. Flight Interception Traps (FITs) installed adjacent to the deadwood enrichments captured 29.465 beetles which were sorted to 566 species. Geographical 'region' was the main factor determining both beetle and fungal assemblages. The proportions of species occurring in all regions were low. Statistic models suggest that assemblages of both taxa differed between stratum and management praxis but their strength varied among regions. Fungal assemblages in Hainich-Dün, for which the data was most comprehensive, discriminated unmanaged from extensively managed and age-class forests (even-aged timber management) while canopy communities differed not from those near the ground. In contrast, the beetle assemblages at the same sites showed the opposite pattern. We pursued an approach in the search for fungus-beetle associations by computing cross correlations and visualize significant links in a network graph. These correlations can be used to formulate hypotheses on mutualistic relationships for example in respect to beetles acting as vectors of fungal spores.


Assuntos
Biodiversidade , Besouros , Fungos , Simbiose , Madeira/microbiologia , Madeira/parasitologia , Animais , Ecossistema , Florestas , Fungos/classificação , Fungos/genética , Árvores
16.
FEMS Microbiol Ecol ; 91(6)2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25953856

RESUMO

Decaying wood hosts a large diversity of seldom investigated protists. Environmental sequencing offers novel insights into communities, but has rarely been applied to saproxylic protists. We investigated the diversity of bright-spored wood-inhabiting Myxomycetes by environmental sequencing. Myxomycetes have a complex life cycle culminating in the formation of mainly macroscopic fruiting bodies, highly variable in shape and colour that are often found on decaying logs. Our hypothesis was that diversity of bright-spored Myxomycetes would increase with decay. DNA was extracted from wood chips collected from 17 beech logs of varying decay stages from the Hainich-Dün region in Central Germany. We obtained 260 partial small subunit ribosomal RNA gene sequences of bright-spored Myxomycetes that were assembled into 29 OTUs, of which 65% were less than 98% similar to those in the existing database. The OTU richness revealed by molecular analysis surpassed that of a parallel inventory of fruiting bodies. We tested several environmental variables and identified pH, rather than decay stage, as the main structuring factor of myxomycete distribution.


Assuntos
DNA de Protozoário/genética , Fagus/parasitologia , Mixomicetos/genética , Madeira/parasitologia , Sequência de Bases , Biodiversidade , Eucariotos , Alemanha , Mixomicetos/classificação , Mixomicetos/isolamento & purificação , Análise de Sequência de DNA , Madeira/química
17.
PLoS One ; 10(3): e0118967, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25749323

RESUMO

Due to the high diversity of bacteria in many ecosystems, their slow generation times, specific but mostly unknown nutrient requirements and syntrophic interactions, isolation based approaches in microbial ecology mostly fail to describe microbial community structure. Thus, cultivation independent techniques, which rely on directly extracted nucleic acids from the environment, are a well-used alternative. For example, bacterial automated ribosomal intergenic spacer analysis (B-ARISA) is one of the widely used methods for fingerprinting bacterial communities after PCR-based amplification of selected regions of the operon coding for rRNA genes using community DNA. However, B-ARISA alone does not provide any taxonomic information and the results may be severely biased in relation to the primer set selection. Furthermore, amplified DNA stemming from mitochondrial or chloroplast templates might strongly bias the obtained fingerprints. In this study, we determined the applicability of three different B-ARISA primer sets to the study of bacterial communities. The results from in silico analysis harnessing publicly available sequence databases showed that all three primer sets tested are specific to bacteria but only two primers sets assure high bacterial taxa coverage (1406f/23Sr and ITSF/ITSReub). Considering the study of bacteria in a plant interface, the primer set ITSF/ITSReub was found to amplify (in silico) sequences of some important crop species such as Sorghum bicolor and Zea mays. Bacterial genera and plant species potentially amplified by different primer sets are given. These data were confirmed when DNA extracted from soil and plant samples were analyzed. The presented information could be useful when interpreting existing B-ARISA results and planning B-ARISA experiments, especially when plant DNA can be expected.


Assuntos
Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Biodiversidade , Primers do DNA , Genes Bacterianos , Reação em Cadeia da Polimerase , RNA Ribossômico/genética , Software , Microbiologia do Solo
18.
PLoS One ; 9(2): e88141, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24505405

RESUMO

Nitrogen availability in dead wood is highly restricted and associations with N-fixing bacteria are thought to enable wood-decaying fungi to meet their nitrogen requirements for vegetative and generative growth. We assessed the diversity of nifH (dinitrogenase reductase) genes in dead wood of the common temperate tree species Fagus sylvatica and Picea abies from differently managed forest plots in Germany using molecular tools. By incorporating these genes into a large compilation of published nifH sequences and subsequent phylogenetic analyses of deduced proteins we verified the presence of diverse pools corresponding to functional nifH, almost all of which are new to science. The distribution of nifH genes strongly correlated with tree species and decay class, but not with forest management, while higher fungal fructification was correlated with decreasing nitrogen content of the dead wood and positively correlated with nifH diversity, especially during the intermediate stage of wood decay. Network analyses based on non-random species co-occurrence patterns revealed interactions among fungi and N-fixing bacteria in the dead wood and strongly indicate the occurrence of at least commensal relationships between these taxa.


Assuntos
Fenômenos Fisiológicos Bacterianos , Fagus/microbiologia , Fungos/fisiologia , Fixação de Nitrogênio , Picea/microbiologia , Madeira/microbiologia , Sequência de Aminoácidos , Bactérias/química , Bactérias/enzimologia , Bactérias/isolamento & purificação , Dinitrogenase Redutase/química , Dinitrogenase Redutase/genética , Ecologia , Fungos/isolamento & purificação , Dados de Sequência Molecular , Filogenia
19.
Sci Rep ; 4: 7014, 2014 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-25388562

RESUMO

The widespread paradigm in ecology that community structure determines function has recently been challenged by the high complexity of microbial communities. Here, we investigate the patterns of and connections between microbial community structure and microbially-mediated ecological function across different forest management practices and temporal changes in leaf litter across beech forest ecosystems in Central Europe. Our results clearly indicate distinct pattern of microbial community structure in response to forest management and time. However, those patterns were not reflected when potential enzymatic activities of microbes were measured. We postulate that in our forest ecosystems, a disconnect between microbial community structure and function may be present due to differences between the drivers of microbial growth and those of microbial function.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas Fúngicas/metabolismo , Folhas de Planta/química , Microbiologia do Solo , Solo/química , Fosfatase Ácida/metabolismo , Biomassa , Celulases/metabolismo , Celulose 1,4-beta-Celobiosidase/metabolismo , Ecossistema , Europa (Continente) , Fagus/fisiologia , Agricultura Florestal/métodos , Florestas , Humanos , Consórcios Microbianos/fisiologia , Peroxidases/metabolismo , Estações do Ano , Árvores/fisiologia
20.
PLoS One ; 9(4): e93700, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24699676

RESUMO

Leaf litter decomposition is the key ecological process that determines the sustainability of managed forest ecosystems, however very few studies hitherto have investigated this process with respect to silvicultural management practices. The aims of the present study were to investigate the effects of forest management practices on leaf litter decomposition rates, nutrient dynamics (C, N, Mg, K, Ca, P) and the activity of ligninolytic enzymes. We approached these questions using a 473 day long litterbag experiment. We found that age-class beech and spruce forests (high forest management intensity) had significantly higher decomposition rates and nutrient release (most nutrients) than unmanaged deciduous forest reserves (P<0.05). The site with near-to-nature forest management (low forest management intensity) exhibited no significant differences in litter decomposition rate, C release, lignin decomposition, and C/N, lignin/N and ligninolytic enzyme patterns compared to the unmanaged deciduous forest reserves, but most nutrient dynamics examined in this study were significantly faster under such near-to-nature forest management practices. Analyzing the activities of ligninolytic enzymes provided evidence that different forest system management practices affect litter decomposition by changing microbial enzyme activities, at least over the investigated time frame of 473 days (laccase, P<0.0001; manganese peroxidase (MnP), P = 0.0260). Our results also indicate that lignin decomposition is the rate limiting step in leaf litter decomposition and that MnP is one of the key oxidative enzymes of litter degradation. We demonstrate here that forest system management practices can significantly affect important ecological processes and services such as decomposition and nutrient cycling.


Assuntos
Enzimas/metabolismo , Florestas , Lignina/metabolismo , Folhas de Planta , Europa (Continente)
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