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| Titel |
Quantification of spatial distribution and spread of bacteria in soil at microscale |
| VerfasserIn |
Archana Juyal, Thilo Eickhorst, Ruth Falconer, Philippe Baveye, Wilfred Otten |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250114625
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| Publikation (Nr.) |
 EGU/EGU2015-15420.pdf |
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| Zusammenfassung |
| Soil bacteria play an essential role in functioning of ecosystems and maintaining of
biogeochemical cycles. Soil is a complex heterogeneous environment comprising of highly
variable and dynamic micro-habitats that have significant impacts on the growth and activity
of resident microbiota including bacteria and fungi. Bacteria occupy a very small portion of
available pore space in soil which demonstrates that their spatial arrangement in soil has a
huge impact on the contact to their target and on the way they interact to carry out their
functions. Due to limitation of techniques, there is scant information on spatial
distribution of indigenous or introduced bacteria at microhabitat scale. There is
a need to understand the interaction between soil structure and microorganisms
including fungi for ecosystem-level processes such as carbon sequestration and
improving the predictive models for soil management. In this work, a combination of
techniques was used including X-ray CT to characterize the soil structure and in-situ
detection via fluorescence microscopy to visualize and quantify bacteria in soil thin
sections.
Pseudomonas fluorescens bacteria were introduced in sterilized soil of aggregate size 1-2
mm and packed at bulk-densities 1.3 g cm-3 and 1.5 g cm-3. A subset of samples was fixed
with paraformaldehyde and subsequently impregnated with resin. DAPI and fluorescence in
situ hybridization (FISH) were used to visualize bacteria in thin sections of soil
cores by epifluorescence microscopy to enumerate spatial distribution of bacteria
in soil. The pore geometry of soil was quantified after X-ray microtomography
scanning.
The distribution of bacteria introduced locally reduced significantly (P |
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