Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Type of Medium
Language
Year
  • 1
    Language: English
    In: Applied and environmental microbiology, September 2011, Vol.77(17), pp.6109-16
    Description: In many areas of China, tidal wetlands have been converted into agricultural land for rice cultivation. However, the consequences of land use changes for soil microbial communities are poorly understood. Therefore, we investigated bacterial and archaeal communities involved in inorganic nitrogen turnover (nitrogen fixation, nitrification, and denitrification) based on abundances and relative species richness of the corresponding functional genes along a soil chronosequence ranging between 50 and 2,000 years of paddy soil management compared to findings for a tidal wetland. Changes in abundance and diversity of the functional groups could be observed, reflecting the different chemical and physical properties of the soils, which changed in terms of soil development. The tidal wetland was characterized by a low microbial biomass and relatively high abundances of ammonia-oxidizing microbes. Conversion of the tidal wetlands into paddy soils was followed by a significant increase in microbial biomass. Fifty years of paddy management resulted in a higher abundance of nitrogen-fixing microbes than was found in the tidal wetland, whereas dominant genes of nitrification and denitrification in the paddy soils showed no differences. With ongoing rice cultivation, copy numbers of archaeal ammonia oxidizers did not change, while that of their bacterial counterparts declined. The nirK gene, coding for nitrite reductase, increased with rice cultivation time and dominated its functionally redundant counterpart, nirS, at all sites under investigation. Relative species richness showed significant differences between all soils with the exception of the archaeal ammonia oxidizers in the paddy soils cultivated for 100 and 300 years. In general, changes in diversity patterns were more pronounced than those in functional gene abundances.
    Keywords: Biodiversity ; Denitrification ; Nitrification ; Nitrogen Fixation ; Soil Microbiology ; Metabolic Networks and Pathways -- Genetics
    ISSN: 00992240
    E-ISSN: 1098-5336
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Soil Biology and Biochemistry, August, 2014, Vol.75, p.197(5)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.soilbio.2014.04.018 Byline: Marie Uksa, Doreen Fischer, Gerhard Welzl, Timo Kautz, Ulrich Kopke, Michael Schloter Abstract: Spatial and temporal dynamics of microbial community structure and function in subsoils have been rarely studied in the past. In this paper we present data on how bacterial communities as well as selected functional groups of microbes change in the rhizosphere, the drilosphere, and in bulk soil over time in topsoil as well as in subsoil. We show that the overall richness of bacteria and abundance of nitrifiers and denitrifiers decreases in bulk soil with soil depth. However, these effects were not or to a much lower degree observed in the rhizosphere and the drilosphere. Temporal fluctuations contributed by far less than spatial factors to the dynamics of bacterial communities and abundance of nitrifiers and denitrifiers in all compartments independent from the soil depth. Author Affiliation: (a) Helmholtz Zentrum Munchen, Research Unit Environmental Genomics, Ingolstadter Landstr. 1, 85758 Oberschleissheim, Germany (b) University of Bonn, Institute of Organic Agriculture, Katzenburgweg 3, 53115 Bonn, Germany Article History: Received 13 November 2013; Revised 8 April 2014; Accepted 11 April 2014
    Keywords: Genetic Research
    ISSN: 0038-0717
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Environmental Pollution, Feb, 2013, Vol.173, p.168(8)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.envpol.2012.09.027 Byline: Fredrick Orori Kengara (a)(b), Ulrike Doerfler (a), Gerhard Welzl (c), Bernhard Ruth (a), Jean Charles Munch (a), Reiner Schroll (a) Abstract: The aim of the study was to induce and enhance the degradation of hexachlorobenzene (HCB), a highly-chlorinated persistent organic pollutant, in two ecologically different tropical soils: a paddy soil (PS) and a non-paddy soil (FS). The degradation of HCB was enhanced using two anaerobic-aerobic cycles in model laboratory experiments. There was greater degradation of HCB in the PS (half-life of 224 days) relative to the FS (half-life of 286 days). It was further shown that soils amended with compost had higher metabolite concentrations relative to the non-amended soils. In the first cycle, there was little degradation of HCB in both soils. However, in the second cycle, there was enhanced mineralization in the PS under aerobic conditions, with the compost-treated samples showing higher mineralization. There was also extensive volatilization in both soils. The metabolite pattern revealed that the increased mineralization and volatilization was due to the formation of lower chlorinated benzenes. Author Affiliation: (a) Helmholtz Zentrum Munchen, German Research Center for Environmental Health (GmbH), Institute of Soil Ecology, 85764 Neuherberg, Germany (b) Department of Chemistry, Maseno University, Private Bag Maseno, Kenya (c) Helmholtz Zentrum Munchen, German Research Center for Environmental Health (GmbH), Institute of Developmental Genetics, 85764 Neuherberg, Germany Article History: Received 19 July 2012; Revised 13 September 2012; Accepted 19 September 2012
    Keywords: Benzene -- Analysis ; Persistent Organic Pollutants -- Analysis ; Metabolites -- Analysis ; Clay Soils -- Analysis ; Soil Ecology -- Analysis
    ISSN: 0269-7491
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Developmental Biology, 15 February 2011, Vol.350(2), pp.496-510
    Description: The balanced proliferation and cell cycle exit of neural progenitors, by generating the appropriate amount of postmitotic progeny at the correct time and in the proper location, is required for the establishment of the highly ordered structure of the adult brain. Little is known about the extrinsic signals regulating these processes, particularly in the midbrain. Fibroblast growth factor (Fgf) 15, the mouse ortholog of FGF19 and member of an atypical Fgf subfamily, is prominently expressed in the dorsolateral midbrain of the midgestational mouse embryo. In the absence of , dorsal midbrain neural progenitors fail to exit the cell cycle and to generate the proper amount of postmitotic neurons. We show here that this is due to the altered expression of inhibitory/neurogenic and proneural/neuronal differentiation helix-loop-helix transcription factor (TF) genes. The expression of , , and was strongly increased and ectopically expanded, whereas the expression of ( ), ( ) and ( ) was strongly decreased and transcription of ( ) was completely abolished in the dorsolateral midbrain of mice. These abnormalities were not caused by the mis-expression of cell cycle regulatory proteins such as cyclin-dependent kinase inhibitors or retinoblastoma proteins. Furthermore, human FGF19 promotes cell cycle exit of murine dorsal neural progenitors . Therefore, our data suggest that Fgf15 is a crucial signaling molecule regulating the postmitotic transition of dorsal neural progenitors and thus the initiation and proper progression of dorsal midbrain neurogenesis in the mouse, by controlling the expression of neurogenic and proneural TFs. ► We have analyzed Fgf15 / mice on an outbred genetic background. ► Dorsal midbrain neural progenitors fail to exit the cell cycle in these mutants. ► Neurogenic bHLH transcription factor genes were up-regulated in Fgf15 / embryos. ► Proneural bHLH transcription factor genes were down-regulated in Fgf15 / embryos. ► Fgf15 controls the initiation and proper progression of dorsal midbrain neurogenesis.
    Keywords: Id1/3 ; Hes5 ; Neurog1/2 ; Cell Cycle Exit ; Neural Progenitors ; Mouse ; Biology ; Zoology
    ISSN: 0012-1606
    E-ISSN: 1095-564X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Soil Biology and Biochemistry, 2011, Vol.43(6), pp.1130-1138
    Description: Effects of decomposers on plant growth are generally ascribed to nutrient mobilization. However, Collembola, which are ubiquitous and abundant decomposers in soil, are known to alter root morphology with, in some cases, the nutrient content of plants remaining unaffected. We studied the interaction of Collembola ( ) with the model plant in order to link phenotypic responses of . to decomposers using changes in gene expression. Collembola reduced the growth of . during early growth stages, but this decrease was compensated later. Expression analyses revealed striking differences in the response of plant roots and shoots three and six days after exposure of to Collembola. Among the specifically affected transcripts in roots, the induction of auxin-responsive genes was significantly increased after six days, suggesting that provoked auxin-related signalling in roots. In shoots, transcriptional changes were more diverse and functional categories involved in defence and metabolic re-arrangements were significantly affected. These responses might have been related to the transitory reduction in growth which presumably was caused by Collembola feeding on and/or damaging roots. The results suggest that Collembola may improve plant resistance against the attack by herbivores by stimulating the production of secondary compounds while concomitantly compensating the costs of producing them by fostering root growth and nutrient exploitation. ► Decomposer animals change auxin signalling in plant roots. ► Concurrently, they induce systemic defence responses in plant shoots. ► Both plant primary and plant secondary metabolism are affected. ► The results have major implications for the view how terrestrial systems function.
    Keywords: Arabidopsis Thaliana ; Auxin ; Collembola ; Microarray ; Protaphorura Fimata ; Soil Fauna ; Agriculture ; Chemistry
    ISSN: 0038-0717
    E-ISSN: 1879-3428
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: PLoS ONE, 01 January 2013, Vol.8(11), p.e80734
    Description: Microbial communities play an important role in cheese ripening and determine the flavor and taste of different cheese types to a large extent. However, under adverse conditions human pathogens may colonize cheese samples during ripening and may thus cause severe outbreaks of diarrhoea and other diseases. Therefore in the present study we investigated the bacterial community structure of three raw ewe's milk cheese types, which are produced without the application of starter cultures during ripening from two production sites based on fingerprinting in combination with next generation sequencing of 16S rRNA gene amplicons. Overall a surprisingly high diversity was found in the analyzed samples and overall up to 213 OTU97 could be assigned. 20 of the major OTUs were present in all samples and include mostly lactic acid bacteria (LAB), mainly Lactococcus, and Enterococcus species. Abundance and diversity of these genera differed to a large extent between the 3 investigated cheese types and in response to the ripening process. Also a large number of non LAB genera could be identified based on phylogenetic alignments including mainly Enterobacteriaceae and Staphylococcacae. Some species belonging to these two families could be clearly assigned to species which are known as potential human pathogens like Staphylococcus saprophyticus or Salmonella spp. However, during cheese ripening their abundance was reduced. The bacterial genera, namely Lactobacillus, Streptococcus, Leuconostoc, Bifidobacterium, Brevibacterium, Corynebacterium, Clostridium, Staphylococcus, Thermoanerobacterium, E. coli, Hafnia, Pseudomonas, Janthinobacterium, Petrotoga, Kosmotoga, Megasphaera, Macrococcus, Mannheimia, Aerococcus, Vagococcus, Weissella and Pediococcus were identified at a relative low level and only in selected samples. Overall the microbial composition of the used milk and the management of the production units determined the bacterial community composition for all cheese types to a large extend, also at the late time points of cheese ripening.
    Keywords: Sciences (General)
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Science of the Total Environment, 15 June 2018, Vol.627, pp.544-552
    Description: Glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) have frequently been detected in surface water and groundwaters. Since adequate glyphosate mineralization in soil may reduce its losses to environment, improved understanding of site specific factors underlying pesticide mineralization in soils is needed. The aim of this study was to investigate the relationship between soil properties and glyphosate mineralization. To establish a sound basis for resilient correlations, the study was conducted with a large number of 21 agricultural soils, differing in a variety of soil parameters, such as soil texture, soil organic matter content, pH, exchangeable ions etc. The mineralization experiments were carried out with C labelled glyphosate at a soil water tension of −15 kPa and at a soil density of 1.3 g cm at 20 ± 1 °C for an incubation period of 32 days. The results showed that the mineralization of glyphosate in different agricultural soils varied to a great extent, from 7 to 70% of the amount initially applied. Glyphosate mineralization started immediately after application, the highest mineralization rates were observed within the first 4 days in most of the 21 soils. Multiple regression analysis revealed exchangeable acidity (H and Al ), exchangeable Ca ions and ammonium lactate extractable K to be the key soil parameters governing glyphosate mineralization in the examined soils. A highly significant negative correlation between mineralized glyphosate and NaOH-extractable residues (NaOH-ER) in soils strongly suggests that NaOH-ER could be used as a simple and reliable parameter for evaluating the glyphosate mineralization capacity. The NaOH-ER were composed of glyphosate, unknown C-residues, and AMPA (12%–65%, 3%–34%, 0%–11% of applied C, respectively). Our results highlighted the influential role of soil exchangeable acidity, which should therefore be considered in pesticide risk assessments and management to limit efficiently the environmental transfers of glyphosate.
    Keywords: Soil Properties ; Exchangeable Acidity ; Aluminium ; Pesticides ; Mineralization ; Non-Extractable Residues ; Environmental Sciences ; Biology ; Public Health
    ISSN: 0048-9697
    E-ISSN: 1879-1026
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: PLoS ONE, 01 January 2013, Vol.8(9), p.e73536
    Description: Understanding factors driving the ecology of N cycling microbial communities is of central importance for sustainable land use. In this study we report changes of abundance of denitrifiers, nitrifiers and nitrogen-fixing microorganisms (based on qPCR data for selected functional genes) in response to different land use intensity levels and the consequences for potential turnover rates. We investigated selected grassland sites being comparable with respect to soil type and climatic conditions, which have been continuously treated for many years as intensely used meadows (IM), intensely used mown pastures (IP) and extensively used pastures (EP), respectively. The obtained data were linked to above ground biodiversity pattern as well as water extractable fractions of nitrogen and carbon in soil. Shifts in land use intensity changed plant community composition from systems dominated by s-strategists in extensive managed grasslands to c-strategist dominated communities in intensive managed grasslands. Along the different types of land use intensity, the availability of inorganic nitrogen regulated the abundance of bacterial and archaeal ammonia oxidizers. In contrast, the amount of dissolved organic nitrogen determined the abundance of denitrifiers (nirS and nirK). The high abundance of nifH carrying bacteria at intensive managed sites gave evidence that the amounts of substrates as energy source outcompete the high availability of inorganic nitrogen in these sites. Overall, we revealed that abundance and function of microorganisms involved in key processes of inorganic N cycling (nitrification, denitrification and N fixation) might be independently regulated by different abiotic and biotic factors in response to land use intensity.
    Keywords: Sciences (General)
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Soil Biology and Biochemistry, August 2014, Vol.75, pp.197-201
    Description: Spatial and temporal dynamics of microbial community structure and function in subsoils have been rarely studied in the past. In this paper we present data on how bacterial communities as well as selected functional groups of microbes change in the rhizosphere, the drilosphere, and in bulk soil over time in topsoil as well as in subsoil. We show that the overall richness of bacteria and abundance of nitrifiers and denitrifiers decreases in bulk soil with soil depth. However, these effects were not or to a much lower degree observed in the rhizosphere and the drilosphere. Temporal fluctuations contributed by far less than spatial factors to the dynamics of bacterial communities and abundance of nitrifiers and denitrifiers in all compartments independent from the soil depth.
    Keywords: Subsoil ; Drilosphere ; Rhizosphere ; Nitrification ; Denitrification ; Bacterial Community Structure ; Agriculture ; Chemistry
    ISSN: 0038-0717
    E-ISSN: 1879-3428
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Soil Biology and Biochemistry, February 2014, Vol.69, pp.179-186
    Description: In this study, drivers for ammonia-oxidation and the related microbial communities (ammonia-oxidizing bacteria and archaea) were investigated in grassland soils on the local as well as on the regional scale focusing on the role of land-use intensity (LUI). To this end, 150 sites from three distinct regions across Germany were selected, covering the whole range of LUI levels (from natural grasslands up to intensive managed meadows). Furthermore, the role of contrasting soil types was analyzed in one of the regions (high vs low organic matter content) for ammonia-oxidation. We revealed a significant increase in potential nitrification rates and abundance of ammonia-oxidizing microbes at two sites on the local level from extensively to intensively managed sites, which indicates that the response pattern of ammonia-oxidizing microbes in grassland soils is likely triggered to a large extent by LUI. However at a third site, where two different soil types were investigated, no correlation between LUI and potential nitrification rates was observed, and only a site-specific effect was apparent. At this site, on the one hand the specific soil type (Histosol) and the related continuous nutrient mobilization from the former peat matrix, as well as the high groundwater level, which could induce a high abundance of methane- oxidizing microbes in the top soil, may be of greater importance as a driver for potential nitrification rates and abundance of ammonia- oxidizing microbes than LUI. On the other hand, the mineral soils of this site were characterized by extreme water shortage, which may also explain the lack of potential nitrification and the abundance of ammonia-oxidizing bacteria and archaea. Thus any extrapolation of local data to regional predictions must be made with care, as factors other than LUI may be of importance if the nitrification potential of a soil is to be described.
    Keywords: Ammonia-Oxidizing Archaea ; Ammonia-Oxidizing Bacteria ; Amoa ; Nitrification ; Peat Soil ; Nitrogen Fixation ; Land-Use Intensity ; Agriculture ; Chemistry
    ISSN: 0038-0717
    E-ISSN: 1879-3428
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages