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41.
Large parts of the central highlands of Mexico are heavily eroded and the success of a planned reforestation program will greatly improve when the organic matter and nutrient content of the soil increases prior to the planting of the trees. This study investigated how the application of biosolids from a pharmaceutical company producing cephalosporines or third generation antibiotics could be used as a soil amendment and affect dynamics of C, P and N in soil. A sandy clay loam soil was sampled, amended with 24 g of dry biosolids kg(-1) dry soil or approximately 32 x 10(3) kg ha(-1) for the 0-10 cm layer, and incubated aerobically while production of carbon dioxide (CO(2)), dynamics of ammonium (NH(4)(+)),nitrite (NO(2)(-)), nitrate (NO(3)(-)), sodium bicarbonate (NaHCO(3)) extractable phosphorus (PO(4)(3-)), and microbial biomass carbon (C) were monitored. Results showed that the biosolid with pH 12, organic C content 162 g kg(-1), total N 21 g kg(-1), was of excellent quality considering its heavy metal content (USEPA) and a class "B" (USEPA) biosolid considering the amount of pathogens. No cephalosporines could be detected in the biosolid. Addition of biosolid to soil increased production of CO(2) 1.4 times and added >60 mg NH(4)(+) kg(-1). The application of biosolids did not significantly increase the concentration of NO(2)(-) which remained <2 mg N kg(-1) soil, but the concentration of NO(3)(-) did increase with 175 mg N kg(-1) soil. The microbial biomass C did not change when sewage biosolids was added and concentrations of extractable PO(4)(3-) only increased temporarily. Washing the biosolids reduced concentrations of NH(4)(+) and NO(3)(-), but also reduced pathogens and concentrations of chloride (Cl(-)), which might pose a treat to humans and the environment, respectively. Although the biosolid added valuable nutrients to the soil and did not inhibit C and N mineralization, further investigation into possible long-term environmental effects on soil processes and plant growth is necessary before this biosolid can be used in the field. 相似文献
42.
Rodrigo Gonzalez-Valencia Armando Sepulveda-Jauregui Karla Martinez-Cruz Jorge Hoyos-Santillan Luc Dendooven Frederic Thalasso 《Hydrobiologia》2014,721(1):9-22
The literature concerning methane (CH4) emissions from temperate and boreal lakes is extensive, but emissions from tropical and subtropical lakes have been less documented. In particular, methane emissions from Mexican lakes, which are often polluted by anthropogenic carbon and nutrient inputs, have not been reported previously. In this work, methane emissions from six Mexican lakes were measured, covering a broad range of organic inputs, trophic states, and climatic conditions. Methane emissions ranged from 5 to 5,000 mg CH4 m?2 day?1. Water samples from several depths in each lake were analyzed for correlation between water quality indicators and methane emissions. Trophic state and water quality indexes were most strongly correlated with methane fluxes. The global methane flux from Mexican freshwater lakes was estimated to be approximately 1.3 Tg CH4 year?1, which is about 20% of methane and 4.4% of total national greenhouse gas emissions. Data for untreated wastewater releases to the environment gave an emission factor of 0.19 kg CH4 kg?1 of Biochemical Oxygen Demand, which is superior to that previously estimated by the IPCC for lake discharges. Thus, the large volume of untreated wastewater in Mexico implies higher methane emission than previously estimated. 相似文献
43.
Changes in methane oxidation activity and methanotrophic community composition in saline alkaline soils 总被引:2,自引:0,他引:2
Nancy Serrano-Silva César Valenzuela-Encinas Rodolfo Marsch Luc Dendooven Rocio J. Alcántara-Hernández 《Extremophiles : life under extreme conditions》2014,18(3):561-571
The soil of the former Lake Texcoco is a saline alkaline environment where anthropogenic drainage in some areas has reduced salt content and pH. Potential methane (CH4) consumption rates were measured in three soils of the former Lake Texcoco with different electrolytic conductivity (EC) and pH, i.e. Tex-S1 a >18 years drained soil (EC 0.7 dS m?1, pH 8.5), Tex-S2 drained for ~10 years (EC 9.0 dS m?1, pH 10.3) and the undrained Tex-S3 (EC 84.8 dS m?1, pH 10.3). An arable soil from Alcholoya (EC 0.7 dS m?1, pH 6.7), located nearby Lake Texcoco was used as control. Methane oxidation in the soil Tex-S1 (lowest EC and pH) was similar to that in the arable soil from Alcholoya (32.5 and 34.7 mg CH4 kg?1 dry soil day?1, respectively). Meanwhile, in soils Tex-S2 and Tex-S3, the potential CH4 oxidation rates were only 15.0 and 12.8 mg CH4 kg?1 dry soil day?1, respectively. Differences in CH4 oxidation were also related to changes in the methane-oxidizing communities in these soils. Sequence analysis of pmoA gene showed that soils differed in the identity and number of methanotrophic phylotypes. The Alcholoya soil and Tex-S1 contained phylotypes grouped within the upland soil cluster gamma and the Jasper Ridge, California JR-2 clade. In soil Tex-S3, a phylotype related to Methylomicrobium alcaliphilum was detected. 相似文献
44.
Inge Vanassche Michael B Drennan Fien Windels Amélie Dendooven Liesbeth Allais Claude A Cuvelier Fons van de Loo Paula S Norris Andrey A Kruglov Sergei A Nedospasov Sylvie Rabot Raul Tito Jeroen Raes Valerie Gaboriau‐Routhiau Nadine Cerf‐Bensussan Tom Van de Wiele Gérard Eberl Carl F Ware Dirk Elewaut 《The EMBO journal》2015,34(4):466-474
Antinuclear antibodies are a hallmark feature of generalized autoimmune diseases, including systemic lupus erythematosus and systemic sclerosis. However, the processes underlying the loss of tolerance against nuclear self‐constituents remain largely unresolved. Using mice deficient in lymphotoxin and Hox11, we report that approximately 25% of mice lacking secondary lymphoid organs spontaneously develop specific antinuclear antibodies. Interestingly, we find this phenotype is not caused by a defect in central tolerance. Rather, cell‐specific deletion and in vivo lymphotoxin blockade link these systemic autoimmune responses to the formation of gut‐associated lymphoid tissue in the neonatal period of life. We further demonstrate antinuclear antibody production is influenced by the presence of commensal gut flora, in particular increased colonization with segmented filamentous bacteria, and IL‐17 receptor signaling. Together, these data indicate that neonatal colonization of gut microbiota influences generalized autoimmunity in adult life. 相似文献
45.
Changes in the bacterial populations of the highly alkaline saline soil of the former lake Texcoco (Mexico) following flooding 总被引:4,自引:0,他引:4
César Valenzuela-Encinas Isabel Neria-González Rocio J. Alcántara-Hernández Isabel Estrada-Alvarado Francisco Javier Zavala-Díaz de la Serna Luc Dendooven Rodolfo Marsch 《Extremophiles : life under extreme conditions》2009,13(4):609-621
Flooding an extreme alkaline-saline soil decreased alkalinity and salinity, which will change the bacterial populations. Bacterial
16S rDNA libraries were generated of three soils with different electrolytic conductivity (EC), i.e. soil with EC 1.7 dS m−1 and pH 7.80 (LOW soil), with EC 56 dS m−1 and pH 10.11 (MEDIUM soil) and with EC 159 dS m−1 and pH 10.02 (HIGH soil), using universal bacterial oligonucleotide primers, and 463 clone 16S rDNA sequences were analyzed
phylogenetically. Library proportions and clone identification of the phyla Proteobacteria, Actinobacteria, Acidobacteria, Cyanobacteria, Bacteroidetes, Firmicutes and Cloroflexi showed that the bacterial communities were different. Species and genera of the Rhizobiales, Rhodobacterales and Xanthomonadales
orders of the α- and γ-subdivision of Proteobacteria were found at the three sites. Species and genera of the Rhodospirillales, Sphingobacteriales, Clostridiales, Oscillatoriales
and Caldilineales were found only in the HIGH soil, Sphingomonadales, Burkholderiales and Pseudomonadales in the MEDIUM soil,
Myxococcales in the LOW soil, and Actinomycetales in the MEDIUM and LOW soils. It was found that the largest diversity at
the order and species level was found in the MEDIUM soil as bacteria of both the HIGH and LOW soils were found in it. 相似文献
46.
N. Verhulst B. Govaerts K. D. Sayre J. Deckers I. M. François L. Dendooven 《Plant and Soil》2009,317(1-2):41-59
Crop growth and yield are the result of the efficiency of the chosen agricultural management system within the boundaries of the agro-ecological environment. Linking spatial variability in crop performance to differences in soil attributes could identify the limiting factors driving the system, since patterns of crop performance will follow the spatial variability of the underlying limiting soil attributes. The Greenseeker handheld NDVI sensor was used to determine the within-plot spatial variability of crop performance in the different management treatments of a long-term (started 1991) tillage and residue management trial. Soil quality was measured spatially in the same plots. Under zero tillage with residue removal, soil quality and crop performance followed micro-topography with higher values where elevation was lower. Under zero tillage with residue retention soil quality was high throughout the field, ensuring uniform crop growth and under conventional tillage, soil quality was intermediate. Crop performance followed the same pattern as soil moisture and the related attributes infiltration, soil structure and organic matter. Thus soil moisture is the main limiting factor of the system and it is essential for the sustainability of any management practice developed for the subtropical highlands that soil water capture and storage are optimal. Zero tillage with residue retention is therefore the practice that will result in the most sustainable management and the most stable yields for this target area. 相似文献
47.
Ruiz-Romero E. Alcántara-Hernández R. Cruz-Mondragon C. Marsch R. Luna-Guido M. L. Dendooven L. 《Plant and Soil》2009,319(1-2):247-257
Plant and Soil - Extreme alkalinity and salinity affects different processes involved in the N cycle, such as mineralization and nitrification, so it might affect the denitrification process and... 相似文献
48.
Henry López-López Nancy Ruiz-Lau Rocío Meza-Gordillo Víctor Manuel Ruiz-Valdiviezo Joseph Galthier Robledo-Luchetti Carlos Alberto Lecona-Guzmán Juan José Villalobos-Maldonado Luc Dendooven Joaquín Adolfo Montes-Molina 《Phyton》2023,92(4):1235-1255
The objective of this work was to evaluate the effect of Beauveria bassiana (Bb 1205) on controlling Fusarium oxysporum f. sp. lycopersici (Fol 17108) in tomato plants in greenhouse conditions. Inoculation of Bb 1205 was the most promising among the agronomic variables and expression of the activity of the enzymes β-1,3-glucanases and chitinases. Inoculation of Bb 1205 occurred at a concentration of 1 × 108 conidia·mL−1, which was administered onto the leaves, directly into the soil and via injection. Infection with Fol 17108 occurred with 1 × 106 spores·mL−1, which were added directly to the soil. Spectrophotometry was used for measuring agronomic parameters, namely activity of chitinases and β-1,3-glucanases in foliage and roots. When Bb 1205 was added to the soil, the chlorophyll index and aerial part length showed significant differences. In addition, it was determined that root length, fresh weight of foliage, flower, and fruit count increased 82 days after inoculation (dai). Chitinase activity induced by Bb 1205 in leaves and roots of tomato plants infected with Fol 17108 was observed when injected into the stem at 32 dai (41.8 and 11.6-fold, respectively). Inoculation on the foliage showed a 10-fold increase of β-1,3-glucanases in the roots after 82 dpi. As for leaves, a 3.8-fold increase was found when the stem was inoculated. In the different in vivo applications, Bb 1205 activated its defenses by expressing the chitinase enzymes and β-1,3-glucanase, thus reducing the damage caused by Fol 17108, demonstrating increase plant growth thereafter. 相似文献
49.
Failure of an iterative curve-fitting procedure to successfully estimate two organic N pools 总被引:1,自引:0,他引:1
Fitting a double negative exponential function to N mineralization data can be used to characterize two organic nitrogen pools; an easily decomposable (Ndpm) and a resistant one (Nrpm). The relevance of those two calculated N mineralization pools was investigated by adding easily decomposable organic material to soils. Soil amended with crop residues of sugar-beet or bean was mixed with an equal amount of coarse sand, incubated at 35 °C and leached at specific time-intervals. Upon leaching, NH4
+ and NO3
- were measured in the extracts. A double negative exponential function was fitted to the data and two organic N pools were defined. Fitting a double negative exponential function to N mineralization data to characterize an active and resistant organic N pool was sometimes impossible; the N mineralization data did not always resemble a negative exponential function. Additionally, the size of the two pools calculated were not constant with time and were often meaningless; the Nrpm pool was greater than the soil organic N content, the size of the Nrpm pool was smaller than the Ndpm pool or one of the N pools was negative. Relevant values for both Nrpm and Ndpm which were consistent with incubation time were only obtained when excessive amounts of organic material, normally not dealt with in the field, were applied. 相似文献
50.