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Caroline Indorf - One of the best experts on this subject based on the ideXlab platform.
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determination of Saprotrophic Fungi turnover in different substrates by glucosamine specific δ13c liquid chromatography isotope ratio mass spectrometry
Fungal Ecology, 2012Co-Authors: Caroline Indorf, Felix Stamm, Jens Dyckmans, Rainer Georg JoergensenAbstract:Abstract A high performance anion exchange chromatography (HPAEC) isotopic ratio mass spectrometry (IRMS) method was developed for amino sugar-specific δ 13 C analysis in plant hydrolysates. The HPAEC-IRMS method provided good validation parameters and the amino sugar concentrations were similar to those obtained by reversed phase (RP) high performance liquid chromatography (HPLC) and fluorescence (Fl) detection. The limit of quantification (LOQ) was 150 μmol l −1 . This optimised HPAEC-IRMS method opens up the possibility of a glucosamine (GlcN) specific δ 13 C analysis in plant material. Thus, it was possible to determine the δ 13 C values in newly formed fungal GlcN for the first time. The formation and turnover of Saprotrophic Fungi was investigated by using the improved HPAEC-IRMS method for GlcN-specific δ 13 C analysis. The cultivation of Saprotrophic Fungi ( Lentinula edodes and Pleurotus species) in beech wood mixed with maize or wheat straw showed the preferred formation of fungal biomass from maize-derived (80%) rather than from beech wood-derived C. The results indicate a faster formation of fungal biomass from maize than from wheat straw as co-substrate.
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Determination of Saprotrophic Fungi turnover in different substrates by glucosamine-specific δ13C liquid chromatography/isotope ratio mass spectrometry
Fungal Ecology, 2012Co-Authors: Caroline Indorf, Felix Stamm, Jens Dyckmans, Rainer Georg JoergensenAbstract:Abstract A high performance anion exchange chromatography (HPAEC) isotopic ratio mass spectrometry (IRMS) method was developed for amino sugar-specific δ 13 C analysis in plant hydrolysates. The HPAEC-IRMS method provided good validation parameters and the amino sugar concentrations were similar to those obtained by reversed phase (RP) high performance liquid chromatography (HPLC) and fluorescence (Fl) detection. The limit of quantification (LOQ) was 150 μmol l −1 . This optimised HPAEC-IRMS method opens up the possibility of a glucosamine (GlcN) specific δ 13 C analysis in plant material. Thus, it was possible to determine the δ 13 C values in newly formed fungal GlcN for the first time. The formation and turnover of Saprotrophic Fungi was investigated by using the improved HPAEC-IRMS method for GlcN-specific δ 13 C analysis. The cultivation of Saprotrophic Fungi ( Lentinula edodes and Pleurotus species) in beech wood mixed with maize or wheat straw showed the preferred formation of fungal biomass from maize-derived (80%) rather than from beech wood-derived C. The results indicate a faster formation of fungal biomass from maize than from wheat straw as co-substrate.
Rainer Georg Joergensen - One of the best experts on this subject based on the ideXlab platform.
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determination of Saprotrophic Fungi turnover in different substrates by glucosamine specific δ13c liquid chromatography isotope ratio mass spectrometry
Fungal Ecology, 2012Co-Authors: Caroline Indorf, Felix Stamm, Jens Dyckmans, Rainer Georg JoergensenAbstract:Abstract A high performance anion exchange chromatography (HPAEC) isotopic ratio mass spectrometry (IRMS) method was developed for amino sugar-specific δ 13 C analysis in plant hydrolysates. The HPAEC-IRMS method provided good validation parameters and the amino sugar concentrations were similar to those obtained by reversed phase (RP) high performance liquid chromatography (HPLC) and fluorescence (Fl) detection. The limit of quantification (LOQ) was 150 μmol l −1 . This optimised HPAEC-IRMS method opens up the possibility of a glucosamine (GlcN) specific δ 13 C analysis in plant material. Thus, it was possible to determine the δ 13 C values in newly formed fungal GlcN for the first time. The formation and turnover of Saprotrophic Fungi was investigated by using the improved HPAEC-IRMS method for GlcN-specific δ 13 C analysis. The cultivation of Saprotrophic Fungi ( Lentinula edodes and Pleurotus species) in beech wood mixed with maize or wheat straw showed the preferred formation of fungal biomass from maize-derived (80%) rather than from beech wood-derived C. The results indicate a faster formation of fungal biomass from maize than from wheat straw as co-substrate.
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Determination of Saprotrophic Fungi turnover in different substrates by glucosamine-specific δ13C liquid chromatography/isotope ratio mass spectrometry
Fungal Ecology, 2012Co-Authors: Caroline Indorf, Felix Stamm, Jens Dyckmans, Rainer Georg JoergensenAbstract:Abstract A high performance anion exchange chromatography (HPAEC) isotopic ratio mass spectrometry (IRMS) method was developed for amino sugar-specific δ 13 C analysis in plant hydrolysates. The HPAEC-IRMS method provided good validation parameters and the amino sugar concentrations were similar to those obtained by reversed phase (RP) high performance liquid chromatography (HPLC) and fluorescence (Fl) detection. The limit of quantification (LOQ) was 150 μmol l −1 . This optimised HPAEC-IRMS method opens up the possibility of a glucosamine (GlcN) specific δ 13 C analysis in plant material. Thus, it was possible to determine the δ 13 C values in newly formed fungal GlcN for the first time. The formation and turnover of Saprotrophic Fungi was investigated by using the improved HPAEC-IRMS method for GlcN-specific δ 13 C analysis. The cultivation of Saprotrophic Fungi ( Lentinula edodes and Pleurotus species) in beech wood mixed with maize or wheat straw showed the preferred formation of fungal biomass from maize-derived (80%) rather than from beech wood-derived C. The results indicate a faster formation of fungal biomass from maize than from wheat straw as co-substrate.
Erik A Hobbie - One of the best experts on this subject based on the ideXlab platform.
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Isotopic Analysis of Sporocarp Protein and Structural Material Improves Resolution of Fungal Carbon Sources
Frontiers in microbiology, 2016Co-Authors: Janet Chen, Kirsten S. Hofmockel, Erik A HobbieAbstract:Fungal acquisition of resources is difficult to assess in the field. To determine whether Fungi received carbon from recent plant photosynthate, litter or soil-derived organic (C:N bonded) nitrogen, we examined differences in δ13C among bulk tissue, structural carbon, and protein extracts of sporocarps of three fungal types: Saprotrophic Fungi, Fungi with hydrophobic ectomycorrhizae or Fungi with hydrophilic ectomycorrhizae. Sporocarps were collected from experimental plots of the Duke Free-air CO2 enrichment (FACE) experiment during and after CO2 enrichment. The differential 13C labeling of ecosystem pools in CO2 enrichment experiments was tracked into Fungi and provided novel insights into organic nitrogen use. Specifically, sporocarp δ13C as well as δ15N of protein and structural material indicated that Fungi with hydrophobic ectomycorrhizae used soil-derived organic nitrogen sources for protein carbon, Fungi with hydrophilic ectomycorrhizae used recent plant photosynthates for protein carbon and both fungal groups used photosynthates for structural carbon. Saprotrophic Fungi depended on litter produced during fumigation for both protein and structural material.
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Fungal functioning in a pine forest: evidence from a 15N‐labeled global change experiment
The New phytologist, 2013Co-Authors: Erik A Hobbie, Linda T. A. Van Diepen, Erik A. Lilleskov, Andrew P. Ouimette, Adrien C. Finzi, Kirsten S. HofmockelAbstract:Summary We used natural and tracer nitrogen (N) isotopes in a Pinus taeda free air CO2 enrichment (FACE) experiment to investigate functioning of ectomycorrhizal and Saprotrophic Fungi in N cycling. Fungal sporocarps were sampled in 2004 (natural abundance and 15N tracer) and 2010 (tracer) and δ15N patterns were compared against litter and soil pools. Ectomycorrhizal Fungi with hydrophobic ectomycorrhizas (e.g. Cortinarius and Tricholoma) acquired N from the Oea horizon or deeper. Taxa with hydrophilic ectomycorrhizas acquired N from the Oi horizon (Russula and Lactarius) or deeper (Laccaria, Inocybe, and Amanita). 15N enrichment patterns for Cortinarius and Amanita in 2010 did not correspond to any measured bulk pool, suggesting that a persistent pool of active organic N supplied these two taxa. Saprotrophic Fungi could be separated into those colonizing pine cones (Baeospora), wood, litter (Oi), and soil (Ramariopsis), with δ15N of taxa reflecting substrate differences. 15N enrichment between sources and sporocarps varied across taxa and contributed to δ15N patterns. Natural abundance and 15N tracers proved useful for tracking N from different depths into fungal taxa, generally corresponded to literature estimates of fungal activity within soil profiles, and provided new insights into interpreting natural abundance δ15N patterns.
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13C and 15N in microarthropods reveal little response of Douglas‐fir ecosystems to climate change
Global Change Biology, 2007Co-Authors: Erik A Hobbie, Paul T Rygiewicz, Mark G. Johnson, Andrew R. MoldenkeAbstract:Understanding ecosystem carbon (C) and nitrogen (N) cycling under global change requires experiments maintaining natural interactions among soil structure, soil communities, nutrient availability, and plant growth. In model Douglas-fir ecosystems maintained for five growing seasons, elevated temperature and carbon dioxide (CO2) increased photosynthesis and increased C storage belowground but not aboveground. We hypothesized that interactions between N cycling and C fluxes through two main groups of microbes, mycorrhizal Fungi (symbiotic with plants) and Saprotrophic Fungi (free-living), mediated ecosystem C storage. To quantify proportions of mycorrhizal and Saprotrophic Fungi, we measured stable isotopes in Fungivorous microarthropods that efficiently censused the fungal community. Fungivorous microarthropods consumed on average 35% mycorrhizal Fungi and 65% Saprotrophic Fungi. Elevated temperature decreased C flux through mycorrhizal Fungi by 7%, whereas elevated CO2 increased it by 4%. The dietary proportion of mycorrhizal Fungi correlated across treatments with total plant biomass (n= 4, r2= 0.96, P= 0.021), but not with root biomass. This suggests that belowground allocation increased with increasing plant biomass, but that mycorrhizal Fungi were stronger sinks for recent photosynthate than roots. Low N content of needles (0.8–1.1%) and A horizon soil (0.11%) coupled with high C : N ratios of A horizon soil (25–26) and litter (36–48) indicated severe N limitation. Elevated temperature treatments increased the Saprotrophic decomposition of litter and lowered litter C : N ratios. Because of low N availability of this litter, its decomposition presumably increased N immobilization belowground, thereby restricting soil N availability for both mycorrhizal Fungi and plant growth. Although increased photosynthesis with elevated CO2 increased allocation of C to ectomycorrhizal Fungi, it did not benefit plant N status. Most N for plants and soil storage was derived from litter decomposition. N sequestration by mycorrhizal Fungi and limited N release during litter decomposition by Saprotrophic Fungi restricted N supply to plants, thereby constraining plant growth response to the different treatments.
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carbon use nitrogen use and isotopic fractionation of ectomycorrhizal and Saprotrophic Fungi in natural abundance and 13c labelled cultures
Fungal Biology, 2004Co-Authors: Erik A Hobbie, Fernando S Sanchez, Paul T RygiewiczAbstract:Stable isotopes in fruit bodies from field studies have been used to infer ectomycorrhizal or Saprotrophic status and to understand carbon and nitrogen use, but few controlled culture studies have correlated source and fungal isotopic patterns. Here, we measured natural abundances of 15N and 13C in ten strains of ectomycorrhizal Fungi and seven strains of Saprotrophic Fungi grown on agar with three different primary carbon sources: glucose, glucose plus malt extract, and potato dextrose agar. Eight fungal strains were also grown using position-specific, 13C-labelled glucose (C-1 through C-6 labelled). Most Fungi resembled nitrogen sources in δ15N, suggesting that growth on agar media minimizes isotopic fractionation on uptake compared to growth on liquid media, and that in general Saprotrophic and mycorrhizal Fungi process nitrogen similarly. Saprotrophic Fungi were more depleted in 13C than ectomycorrhizal Fungi on all media, presumably because of assimilation of 13C-depleted, agar-derived carbon. Results on 13C-enriched glucose indicated that Saprotrophic Fungi obtained up to 45% of their carbon from the agar substrate. Fungi generally incorporated the individual carbon atoms of glucose in the order, C-4
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Carbon use, nitrogen use, and isotopic fractionation of ectomycorrhizal and Saprotrophic Fungi in natural abundance and 13C-labelled cultures.
Mycological research, 2004Co-Authors: Erik A Hobbie, Fernando S Sanchez, Paul T RygiewiczAbstract:Stable isotopes in fruit bodies from field studies have been used to infer ectomycorrhizal or Saprotrophic status and to understand carbon and nitrogen use, but few controlled culture studies have correlated source and fungal isotopic patterns. Here, we measured natural abundances of 15N and 13C in ten strains of ectomycorrhizal Fungi and seven strains of Saprotrophic Fungi grown on agar with three different primary carbon sources: glucose, glucose plus malt extract, and potato dextrose agar. Eight fungal strains were also grown using position-specific, 13C-labelled glucose (C-1 through C-6 labelled). Most Fungi resembled nitrogen sources in delta 15N, suggesting that growth on agar media minimizes isotopic fractionation on uptake compared to growth on liquid media, and that in general Saprotrophic and mycorrhizal Fungi process nitrogen similarly. Saprotrophic Fungi were more depleted in 13C than ectomycorrhizal Fungi on all media, presumably because of assimilation of 13C-depleted, agar-derived carbon. Results on 13C-enriched glucose indicated that Saprotrophic Fungi obtained up to 45 % of their carbon from the agar substrate. Fungi generally incorporated the individual carbon atoms of glucose in the order, C-4 < C-1 < C-2, C-3, C-5 < C-6, ranging from a mean of 9 % for the C-4 atom to 21 % for the C-6 atom. Based on these incorporation patterns and intramolecular 13C patterns within glucose, differential incorporation of carbon atoms within glucose among fungal taxa contributed less than 1% to isotopic differences among taxa, whereas isotopic fractionation among taxa during metabolism varied up to 4%. Parallel studies of 13C-enriched and natural abundance substrates were crucial to interpreting our results.
Lingling Shi - One of the best experts on this subject based on the ideXlab platform.
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changes in fungal communities across a forest disturbance gradient
Applied and Environmental Microbiology, 2019Co-Authors: Lingling Shi, Gbadamassi G O Dossa, Ekananda Paudel, Huadong Zang, Rhett D HarrisonAbstract:ABSTRACT Deforestation has a substantial impact on aboveground biodiversity, but the response of belowground soil Fungi remains poorly understood. In a tropical montane rainforest in southwestern China, plots were established along a forest degradation gradient ranging from mature and regenerated forests to open land to examine the impacts of forest degradation and deforestation on ecosystem diversity and function. Here, we evaluated the changes in belowground fungal diversity and community composition using a metabarcoding approach. Soil Saprotrophic fungal richness declined with increasing forest disturbance. For example, Penicillium spp. (phosphorus [P]-solubilizing Fungi) dominated in mature forest but were less abundant in regenerating forests and showed the lowest abundance in open land sites. Conversely, the abundance of facultative pathogenic Fungi increased along the disturbance gradient. The decline in soil saprophytic Fungi may be a direct result of forest disturbance or it may be associated with increased availability of soil phosphorus indirectly through an increase in soil pH. The increase in abundance of facultative pathogenic Fungi may be related to reduced competition with Saprotrophic Fungi, changes in microclimate, or increased spore rain. These results demonstrate a loss of dominant P-solubilizing Saprotrophic Fungi along the disturbance gradient, indicating a change from soil P limitation in mature tropical forests to soil C limitation in deforested sites. The increased prevalence of pathogenic Fungi may inhibit plant succession following deforestation. Overall, this research demonstrates that soil Fungi can be used as a sensitive indicator for soil health to evaluate the consequences of forest disturbance. IMPORTANCE The soil fungal functional group changes in response to forest disturbance and indicates a close interaction between the aboveground plant community and the belowground soil biological community. Soil Saprotrophic Fungi declined in relative abundance with increasing forest disturbance. At the same time, the relative abundance of facultative pathogenic Fungi increased. The loss of Saprotrophic fungal richness and abundance may have been a direct result of forest disturbance or an indirect result of changes in soil pH and soil P. Furthermore, the dominant P-solubilizing Saprotrophic Fungi were replaced by diverse facultative pathogenic Fungi, which have weaker C decomposition ability. These changes potentially indicate a shift from soil phosphate limitation to carbon limitation following deforestation. This study suggests that changes in fungal functional group composition can be used as an indicator of the effects of forest disturbance on soil carbon and nutrients.
Pål Axel Olsson - One of the best experts on this subject based on the ideXlab platform.
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Temporal patterns of carbon flow from grassland vegetation to soil microorganisms measured using 13C-labelling and signature fatty acids
Plant and Soil, 2021Co-Authors: Johanna Birgander, Pål Axel OlssonAbstract:Purpose We investigated how the C flow from plants to microorganisms varies throughout the year in a temperate grassland. Additionally, we investigated how the C flow relates to Saprotrophic activity and vegetation changes. Methods In situ stable isotope pulse labelling (^13CO_2) was employed to estimate the flow of recently plant-derived C to soil microorganisms by using signature fatty acids. Bacterial and fungal growth was estimated using radio-labelling in laboratory incubations. Results The C flow from plants to arbuscular mycorrhizal (AM) Fungi peaked during the warmer parts of the year, but Saprotrophic microorganisms showed little temporal variation in C flow. Also Saprotrophic Fungi received considerable amounts of C from plants throughout the year. Bacterial and fungal growth showed temporal variation with a growth peak in August for both. This suggests a shift in the C source from mainly rhizosphere C in colder parts of the year, to older C-sources in warmer parts of the year (August). Conclusion We conclude that AM Fungi, Saprotrophic Fungi and bacteria differ in the amount of recently-fixed C they receive from plants throughout the year. Hence, temporal patterns need to be considered to understand ecosystem functioning. The studied plant community included winter annuals, which potentially maintain a high C flow to Saprotrophic Fungi during the cold season.
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Temporal patterns of carbon flow from grassland vegetation to soil microorganisms measured using 13C-labelling and signature fatty acids
Plant and Soil, 2021Co-Authors: Johanna Birgander, Pål Axel OlssonAbstract:We investigated how the C flow from plants to microorganisms varies throughout the year in a temperate grassland. Additionally, we investigated how the C flow relates to Saprotrophic activity and vegetation changes. In situ stable isotope pulse labelling (13CO2) was employed to estimate the flow of recently plant-derived C to soil microorganisms by using signature fatty acids. Bacterial and fungal growth was estimated using radio-labelling in laboratory incubations. The C flow from plants to arbuscular mycorrhizal (AM) Fungi peaked during the warmer parts of the year, but Saprotrophic microorganisms showed little temporal variation in C flow. Also Saprotrophic Fungi received considerable amounts of C from plants throughout the year. Bacterial and fungal growth showed temporal variation with a growth peak in August for both. This suggests a shift in the C source from mainly rhizosphere C in colder parts of the year, to older C-sources in warmer parts of the year (August). We conclude that AM Fungi, Saprotrophic Fungi and bacteria differ in the amount of recently-fixed C they receive from plants throughout the year. Hence, temporal patterns need to be considered to understand ecosystem functioning. The studied plant community included winter annuals, which potentially maintain a high C flow to Saprotrophic Fungi during the cold season.
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the use of fatty acid signatures to study mycelial interactions between the arbuscular mycorrhizal fungus glomus intraradices and the Saprotrophic fungus fusarium culmorum in root free soil
Fungal Biology, 1998Co-Authors: John Larsen, Pål Axel Olsson, Iver JakobsenAbstract:The Saprotrophic fungus Fusarium culmorum, Penicillium hordei, Rhizoctonia solani and Trichoderma harzianum and the arbuscular mycorrhizal fungus Glomus intraradices were examined for content of phospholipid fatty acids (PLFA) and neutral lipid fatty acids (NLFA). The AM fungus differed from the Saprotrophic Fungi especially by its content of the fatty acid 16:1ω5 which was absent in the saprotrophs. The fatty acid 18:2ω6,9 was the dominant fatty acid of the Saprotrophic Fungi while it was negligible in mycelium of G. intraradices. Specificity in content of fatty acids made it possible to quantify G. intraradices. and F. culmorum simultaneously in soil. Furthermore, a compartmented growth system made it possible to study mycelial interactions in the absence of roots. We measured hyphal spread of both Fungi, hyphal 33P transport of G. intraradices and sporulation of F. culmorum. The two Fungi did not interact according to the parameters used in this study. We conclude that fatty acid signatures may be a valuable tool when studying interactions between AM Fungi and other Fungi in root-free soil.
