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Manyun Zhang - One of the best experts on this subject based on the ideXlab platform.
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effects of nitrification inhibitor 3 4 dimethylpyrazole phosphate and fungicide iprodione on soil Fungal Biomass and community based on internal transcribed spacer region
Journal of Soils and Sediments, 2017Co-Authors: Manyun Zhang, Yaling Zhang, Ying Teng, Rebecca FordAbstract:Nitrification inhibitors that impact soil nitrifying microorganisms have been widely applied in agricultural soils to enhance the efficiency of nitrogen fertilizers. However, little is known about their combined impact with other chemical applications, such as fungicides, on soil fungi. This study specifically examined the effects of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP), alone or together with the fungicide iprodione, on fungi Biomass and community in a typical farmland soil. Four treatments were set: (1) control of zero agrochemical applications (CK), (2) a single DMPP application (DAA), (3) repeated iprodione applications (4×IPR), and (4) combined applications of DMPP and iprodione (DAA+4×IPR). The agrochemicals were applied at the recommended intervals, and the soil samples were incubated in the dark for 28 days. During the incubation, soil sample DNA was extracted, and the effects of DMPP and iprodione applications on soil Fungal internal transcribed spacer (ITS) abundances were determined with quantitative PCR (qPCR). At the end of the incubation, Illumina MiSeq method was employed to assess soil Fungal community diversity and structure. DMPP application had a negligible effect on Fungal ITS abundance. However, repeated iprodione applications significantly decreased Fungal ITS abundances. After 28 days of incubation, the Fungal ITS abundances in the 4×IPR and DAA+4×IPR treatments were 43.6 and 56.2% of that measured from the CK treatment, respectively. Shannon indices of Fungal communities demonstrated the treatment-induced gradients, with the DAA+4×IPR treatment harboring the highest Shannon index. Fungal community structures following the DAA and 4×IPR treatments remained overlapping with that in the CK treatment, but repeated iprodione applications markedly enriched the family Teratosphaeriaceae. Relative to the CK treatment, Fungal community structure in the DAA+4×IPR treatment was significantly changed, with the families Cephalothecaceae, Hypocreaceae, and Cordycipitaceae harboring a linear discriminant analysis value >3. DMPP application had negligible effects on soil Fungal Biomass, community diversity, and structure, potentially indicating that the DMPP is “bio-safe.” Conversely, repeated iprodione applications significantly decreased Fungal ITS abundances. Moreover, the family Teratosphaeriaceae could be further investigated as a potential biomarker of the impacts of iprodione on soil fungi. The combined applications of DMPP and iprodione stimulated the Shannon diversity index and markedly changed soil Fungal community structure.
Suman Khowala - One of the best experts on this subject based on the ideXlab platform.
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removal of hexavalent chromium by heat inactivated Fungal Biomass of termitomyces clypeatus surface characterization and mechanism of biosorption
Chemical Engineering Journal, 2011Co-Authors: Lata Ramrakhiani, Rajib Majumder, Suman KhowalaAbstract:Abstract Mechanism of Cr(VI) biosorption by heat inactivated Fungal Biomass of Termitomyces clypeatus was studied by analyzing its pH profile and surface chemistry. The biosorption efficiency enhanced with acid pretreatment and reduced by alkali. The pretreatment with CaCl2 increased the biosorption capacity but decreased with NaCl. Surface chemistry was characterized by potentiometric titration pH of zero charge and SEM–EDX analysis. The acidic and basic sites for the Biomass were quantified as 7.75 and 3.25 mmol/g, respectively, and concluded that surface of the Biomass was acidic. Acidic [carboxyl (pKa 3.45 and 4.29), imidazole (pKa 5.98), and phosphate (pKa 6.75)] and alkaline [amines (pKa 9.96, 11.92, and 12.47), sulfhydryl (thiol) (pKa 8.48), hydroxyl (pKa 11.12)] functional groups were identified and confirmed by FTIR analysis. The roles played by functional groups in chromium biosorption were found to be in the order: carboxyl > phosphates > lipids > sulfhydryl > amines. Integrative analysis of surface chemistry, functional group modification and FTIR showed that the Cr(VI) biosorption involved more than one mechanism such as physical adsorption, ion exchange, complexation and electrostatic attraction and followed in two subsequent steps – Cr2O72− biosorption at the protonated active sites (amino, carboxyl and phosphate groups) and reduction of Cr(VI) to Cr(III) by reductive groups (hydroxyl and carbonyl groups) on the Biomass surface.
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removal of hexavalent chromium by heat inactivated Fungal Biomass of termitomyces clypeatus surface characterization and mechanism of biosorption
Chemical Engineering Journal, 2011Co-Authors: Lata Ramrakhiani, Rajib Majumde, Suman KhowalaAbstract:Abstract Mechanism of Cr(VI) biosorption by heat inactivated Fungal Biomass of Termitomyces clypeatus was studied by analyzing its pH profile and surface chemistry. The biosorption efficiency enhanced with acid pretreatment and reduced by alkali. The pretreatment with CaCl2 increased the biosorption capacity but decreased with NaCl. Surface chemistry was characterized by potentiometric titration pH of zero charge and SEM–EDX analysis. The acidic and basic sites for the Biomass were quantified as 7.75 and 3.25 mmol/g, respectively, and concluded that surface of the Biomass was acidic. Acidic [carboxyl (pKa 3.45 and 4.29), imidazole (pKa 5.98), and phosphate (pKa 6.75)] and alkaline [amines (pKa 9.96, 11.92, and 12.47), sulfhydryl (thiol) (pKa 8.48), hydroxyl (pKa 11.12)] functional groups were identified and confirmed by FTIR analysis. The roles played by functional groups in chromium biosorption were found to be in the order: carboxyl > phosphates > lipids > sulfhydryl > amines. Integrative analysis of surface chemistry, functional group modification and FTIR showed that the Cr(VI) biosorption involved more than one mechanism such as physical adsorption, ion exchange, complexation and electrostatic attraction and followed in two subsequent steps – Cr2O72− biosorption at the protonated active sites (amino, carboxyl and phosphate groups) and reduction of Cr(VI) to Cr(III) by reductive groups (hydroxyl and carbonyl groups) on the Biomass surface.
Rebecca Ford - One of the best experts on this subject based on the ideXlab platform.
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effects of nitrification inhibitor 3 4 dimethylpyrazole phosphate and fungicide iprodione on soil Fungal Biomass and community based on internal transcribed spacer region
Journal of Soils and Sediments, 2017Co-Authors: Manyun Zhang, Yaling Zhang, Ying Teng, Rebecca FordAbstract:Nitrification inhibitors that impact soil nitrifying microorganisms have been widely applied in agricultural soils to enhance the efficiency of nitrogen fertilizers. However, little is known about their combined impact with other chemical applications, such as fungicides, on soil fungi. This study specifically examined the effects of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP), alone or together with the fungicide iprodione, on fungi Biomass and community in a typical farmland soil. Four treatments were set: (1) control of zero agrochemical applications (CK), (2) a single DMPP application (DAA), (3) repeated iprodione applications (4×IPR), and (4) combined applications of DMPP and iprodione (DAA+4×IPR). The agrochemicals were applied at the recommended intervals, and the soil samples were incubated in the dark for 28 days. During the incubation, soil sample DNA was extracted, and the effects of DMPP and iprodione applications on soil Fungal internal transcribed spacer (ITS) abundances were determined with quantitative PCR (qPCR). At the end of the incubation, Illumina MiSeq method was employed to assess soil Fungal community diversity and structure. DMPP application had a negligible effect on Fungal ITS abundance. However, repeated iprodione applications significantly decreased Fungal ITS abundances. After 28 days of incubation, the Fungal ITS abundances in the 4×IPR and DAA+4×IPR treatments were 43.6 and 56.2% of that measured from the CK treatment, respectively. Shannon indices of Fungal communities demonstrated the treatment-induced gradients, with the DAA+4×IPR treatment harboring the highest Shannon index. Fungal community structures following the DAA and 4×IPR treatments remained overlapping with that in the CK treatment, but repeated iprodione applications markedly enriched the family Teratosphaeriaceae. Relative to the CK treatment, Fungal community structure in the DAA+4×IPR treatment was significantly changed, with the families Cephalothecaceae, Hypocreaceae, and Cordycipitaceae harboring a linear discriminant analysis value >3. DMPP application had negligible effects on soil Fungal Biomass, community diversity, and structure, potentially indicating that the DMPP is “bio-safe.” Conversely, repeated iprodione applications significantly decreased Fungal ITS abundances. Moreover, the family Teratosphaeriaceae could be further investigated as a potential biomarker of the impacts of iprodione on soil fungi. The combined applications of DMPP and iprodione stimulated the Shannon diversity index and markedly changed soil Fungal community structure.
Erland Baath - One of the best experts on this subject based on the ideXlab platform.
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Fungal Biomass production and turnover in soil estimated using the acetate in ergosterol technique
Soil Biology & Biochemistry, 2007Co-Authors: Johannes Rousk, Erland BaathAbstract:We report the first attempt to estimate Fungal Biomass production in soil by correlating relative Fungal growth rates (i.e., acetate incorporation into ergosterol) with Fungal Biomass increase (i.e., ergosterol) following amendments with dried alfalfa or barley straw in soil. The conversion factor obtained was then used in unamended soil, resulting in Fungal Biomass productions of 10–12 μg C g−1 soil, yielding Fungal turnover times between 130 and 150 days. Using a conversion factor from alfalfa-treated soil only resulted in two times higher estimates for Biomass production and consequently lower turnover times. Comparing Fungal Biomass production with basal respiration indicated that these calculations overestimated the former. Still, the turnover times of Fungal Biomass in soil were in the same range as turnover times estimated in aquatic systems. The slow turnover of Fungal Biomass contrasts with the short turnover times found for bacteria. The study thus presents empirical data substantiating the theoretical division of bacteria and fungi into a fast and a slow energy channel, respectively, in the soil food web.
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can the extent of degradation of soil Fungal mycelium during soil incubation be used to estimate ectomycorrhizal Biomass in soil
Soil Biology & Biochemistry, 2004Co-Authors: Erland Baath, Lars Nilsson, Hans Goransson, Hakan WallanderAbstract:The extent of degradation of the Fungal Biomass in forest soil during laboratory incubation was investigated as a measure of ectomycorrhizal (EM) Biomass. The method simulates the disappearance of Fungal mycelium after root trenching, where the EM fungi, deprived of its energy source (the tree), will start to die off. Incubating a forest humus soil at 25 C resulted in a decrease in the relative proportion (mol%) of the phospholipid fatty acid 18:2omega6,9 (a Fungal marker molecule) within 3-6 months, indicating that Fungal Biomass was disappearing. Incubation at 5 degreesC resulted in essentially no change in the amount of 18:2omega6,9. The measurement of ergosterol, another Fungal marker molecule, gave similar results. Incubation of different forest soils (pine, spruce and spruce/oak), and assuming that the disappearance of Fungal Biomass during this period of time was entirely due to EM fungi, resulted in an estimation of EM Biomass of between 47 and 84% of the total Fungal Biomass in these soils. The humus layer had more EM Biomass than deeper mineral layers. (Less)
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estimation of conversion factors for Fungal Biomass determination in compost using ergosterol and plfa 18 2 omega 6 9
Soil Biology & Biochemistry, 2004Co-Authors: Morten Klamer, Erland BaathAbstract:Eleven species of common fungi from compost were analysed for their content of ergosterol and phospholipid fatty acids (PLFAs) after growth on agar media. Mean content of ergosterol was 3.1 mg g(-1) dw of Fungal mycelium (range 1-24 mg g(-1) dw). Total amount of PLFAs varied between 2.6 and 43.5 mumol g(-1) dw of fungi (mean 14.9 mumol g(-1) dw). The most common PLFAs were 16:0,18:2omega6,9 and 18:1omega9 comprising between 79 and 97 mol% of the total amount of PLFAs. The PLFA 18:2omega6,9, suggested as a marker molecule for fungi, comprised between 36 and 61 mol% of the total PLFAs in the Ascomycetes, between 45 and 57 mol% in the Basidiomycetes and 1222 mol% in the Zygomycetes. There was a good correlation between the content of the two Fungal marker molecules, ergosterol and the PLFA 18:2omega6,9, with a mean content of 1 mg ergosterol being equivalent to 2.1 mumol of 18:2omega6,9. Based on results from the Fungal isolates, conversion factors were calculated (5.4 mg ergosterol g(-1) Biomass C and 11.8 mumol 18:2omega6,9 g(-1) Biomass Q and applied to compost samples in which both the ergosterol and the PLFA 18:2omega6,9 content had been measured. This resulted in similar estimates of Fungal Biomass C using the two marker molecules, but was three to five times higher than total microbial Biomass C calculated using ATP content in the compost. This could partly be explained by the fact that both of the markers used for Fungal Biomass are cell membrane constituents. Thus, the ergosterol and the PLFA content were related to the hyphal diameter of the fungi, where fungi with thinner hyphae had higher ergosterol concentrations than fungi with thicker hyphae. This could also partly explain the large interspecific variation in content of the two marker molecules. (C) 2003 Elsevier Ltd. All rights reserved. (Less)
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the use of phospholipid fatty acid analysis to estimate bacterial and Fungal Biomass in soil
Biology and Fertility of Soils, 1996Co-Authors: Asa Frostegard, Erland BaathAbstract:The cell content of 12 bacterial phospholipid fatty acids (PLFA) was determined in bacteria extracted from soil by homogenization/centrifugation. The bacteria were enumerated using acridine orange direct counts. An average of 1.40×10-17 mol bacterial PLFA cell-1 was found in bacteria extracted from 15 soils covering a wide range of pH and organic matter contents. With this factor, the bacterial Biomass based on PLFA analyses of whole soil samples was calculated as 1.0–4.8 mg bacterial C g-1 soil C. The corresponding range based on microscopical counts was 0.3–3.0 mg bacterial C g-1 soil C. The recovery of bacteria from the soils using homogenization/centrifugation was 2.6–16% (mean 8.7%) measured by PLFA analysis, and 12–61% (mean 26%) measured as microscopical counts. The soil content of the PLFA 18:2ω6 was correlated with the ergosterol content (r=0.92), which supports the use of this PLFA as an indicator of Fungal Biomass. The ratio 18:2ω6 to bacterial PLFA is therefore suggested as an index of the Fungal:bacterial Biomass ratio in soil. An advantage with the method based on PLFA analyses is that the same technique and even the same sample is used to determine both fungi and bacteria. The Fungal:bacterial Biomass ratio calculated in this way was positively correlated with the organic matter content of the soils (r=0.94).
Jong Moon Park - One of the best experts on this subject based on the ideXlab platform.
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use of dead Fungal Biomass for the detoxification of hexavalent chromium screening and kinetics
Process Biochemistry, 2005Co-Authors: Donghee Park, Yeoungsang Yun, Jong Moon ParkAbstract:Abstract The removal of hexavalent chromium from aqueous solution was carried out in batch experiments using dead Biomass of four Fungal strains – Aspergillus niger , Rhizopus oryzae , Saccharomyces cerevisiae and Penicillium chrysogenum . All of these dead Fungal Biomass completely removed Cr(VI) from aqueous solutions, that of R . oryzae being the most effective. Cr(VI) was removed from aqueous solutions by the reduction to Cr(III) when it contacted with the Biomass. The removal rate of Cr(VI) increased with a decrease in pH or with increases of Cr(VI) and Biomass concentrations. In particular, the removal rate of Cr(VI) was proportional to total chromate concentration [Cr(VI)], and equivalent concentration of organic compounds [OC], suggesting a simple rate equation in a form of d[Cr(VI)]/d t = − k [Cr(VI)][OC]. This model fitted well with the experimental data obtained at pH 2, supporting the mechanism that Cr(VI) is removed via a redox reaction. From the practical view point, the abundant and inexpensive dead Fungal Biomass could be used for the conversion of toxic Cr(VI) into less toxic or nontoxic Cr(III).
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mechanism of hexavalent chromium removal by dead Fungal Biomass of aspergillus niger
Water Research, 2005Co-Authors: Donghee Park, Yeoungsang Yun, Jong Moon ParkAbstract:When synthetic wastewater containing Cr(VI) was placed in contact with the dead Fungal Biomass of Aspergillus niger, the Cr(VI) was completely removed from aqueous solution, whereas Cr(III), which was not initially present, appeared in aqueous solution. Desorption and X-ray photoelectron spectroscopy (XPS) studies showed that most of the Cr bound on the Biomass was in trivalent form. These results indicated that the main mechanism of Cr(VI) removal was a redox reaction between Cr(VI) and the dead Fungal Biomass, which is quite different from previously reported mechanisms. The influences of contact time, pH, Cr(VI) concentration, Biomass concentration and temperature on Cr(VI) removal were also evaluated. The Cr(VI) removal rate increased with a decrease in pH and with increases in Cr(VI) concentration, Biomass concentration and temperature. Although removal kinetics was dependent on the experimental conditions, Cr(VI) was completely removed in the aqueous solution. In conclusion, a new mechanism of Cr(VI) removal by the dead Fungal Biomass has been proposed. From a practical viewpoint, this abundant and inexpensive dead Fungal Biomass has potential application in the conversion of toxic Cr(VI) into less toxic or nontoxic Cr(III).
