Persistent Link:
http://hdl.handle.net/10150/284093
Title:
Bacterial transport, distribution and activity in porous media
Author:
Jordan, Fiona Lya
Issue Date:
2000
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Understanding the extent of microbial transport, distribution and activity in the subsurface is paramount for effective in-situ bioremediation. In one study, we investigated the impact a substrate pulse has on the movement of inoculated or indigenous bacteria through saturated porous media. In another study, we developed a method to visualize the distribution of bacteria on soil surfaces. The elution of either inoculated or indigenous bacteria was monitored from model (homogenous) sand or natural (heterogenous) soil column systems. Sand columns receiving salicylate resulted in enhanced elution of inoculated P. putida. However, the salicylate pulse did not result in enhanced elution of P. putida from a natural system. For natural heterogenous systems, the salicylate pulse significantly affected the elution of certain indigenous bacteria. Specifically, more heterotrophs were eluted from soil columns receiving salicylate than from those that did not for both loamy sand soils tested. On the other hand, there were consistently fewer salicylate-degrading cells eluted in the presence of salicylate from one of the two soils tested. These data suggest that bacterial transport is a function of both the porous medium and the microbial population(s) under investigation. In the second study, an agar lift-DNA/DNA hybridization technique was developed to visualize the distribution of eubacteria on soil surfaces. Briefly, a single layer of soil was lifted from the surface of soil microcosms onto agar slabs and allowed to incubate. Bacterial colonies were lifted from the agar slabs onto membranes. The location of individual colonies was detected on the membranes by hybridization with a probe complementary to a conserved region of the eubacterial genome. This method was able to detect active microorganisms on different soil surfaces. The probe signal correlated well with the number of metabolically active microorganisms found in soils amended with a carbon source. This technique also allowed for visualization of localized microbial activity. A combined approach utilizing both soil column studies and the agar-lift technique should allow researchers to better elucidate microbial transport, distribution and activity in subsurface environments.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Biology, Microbiology.; Biogeochemistry.; Agriculture, Soil Science.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Soil, Water and Environmental Science
Degree Grantor:
University of Arizona
Advisor:
Maier, R. M.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleBacterial transport, distribution and activity in porous mediaen_US
dc.creatorJordan, Fiona Lyaen_US
dc.contributor.authorJordan, Fiona Lyaen_US
dc.date.issued2000en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractUnderstanding the extent of microbial transport, distribution and activity in the subsurface is paramount for effective in-situ bioremediation. In one study, we investigated the impact a substrate pulse has on the movement of inoculated or indigenous bacteria through saturated porous media. In another study, we developed a method to visualize the distribution of bacteria on soil surfaces. The elution of either inoculated or indigenous bacteria was monitored from model (homogenous) sand or natural (heterogenous) soil column systems. Sand columns receiving salicylate resulted in enhanced elution of inoculated P. putida. However, the salicylate pulse did not result in enhanced elution of P. putida from a natural system. For natural heterogenous systems, the salicylate pulse significantly affected the elution of certain indigenous bacteria. Specifically, more heterotrophs were eluted from soil columns receiving salicylate than from those that did not for both loamy sand soils tested. On the other hand, there were consistently fewer salicylate-degrading cells eluted in the presence of salicylate from one of the two soils tested. These data suggest that bacterial transport is a function of both the porous medium and the microbial population(s) under investigation. In the second study, an agar lift-DNA/DNA hybridization technique was developed to visualize the distribution of eubacteria on soil surfaces. Briefly, a single layer of soil was lifted from the surface of soil microcosms onto agar slabs and allowed to incubate. Bacterial colonies were lifted from the agar slabs onto membranes. The location of individual colonies was detected on the membranes by hybridization with a probe complementary to a conserved region of the eubacterial genome. This method was able to detect active microorganisms on different soil surfaces. The probe signal correlated well with the number of metabolically active microorganisms found in soils amended with a carbon source. This technique also allowed for visualization of localized microbial activity. A combined approach utilizing both soil column studies and the agar-lift technique should allow researchers to better elucidate microbial transport, distribution and activity in subsurface environments.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectBiology, Microbiology.en_US
dc.subjectBiogeochemistry.en_US
dc.subjectAgriculture, Soil Science.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineSoil, Water and Environmental Scienceen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMaier, R. M.en_US
dc.identifier.proquest9965872en_US
dc.identifier.bibrecord.b40479742en_US
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