Development of a whole-cell based biosensor technique for assessment of bioavailability and toxicity of heavy metals in soil

2.50
Hdl Handle:
http://hdl.handle.net/10547/133551
Title:
Development of a whole-cell based biosensor technique for assessment of bioavailability and toxicity of heavy metals in soil
Authors:
Ding, Yurong
Abstract:
The aim of this study was to develop a suitable monitoring protocol for mediated amperometric whole-cell biosensors for in situ assessment of heavy metals in soil. E. coli 8277, Pseudomonas 9773, Pseudomonas 9046 and Pseudomonas 8917 were screened as biosensor catalysts to select the sensitive biosensor configurations to heavy metals. A new protocol was developed for monitoring heavy metals in defined solution, soil pore water, and in situ in soil. This study also demonstrated the applications of mediated amperometric bacterial biosensors for in situ assessing the bioavailability and toxicity of heavy metals in freshly spiked soils or historically contaminated soils, and mixture toxicities of heavy metals. It was found that the biosensors incorporating selected bacterial strains were appropriately sensitive to copper, but less sensitive to Zn, Pb, and Hg, compared to Microtox assay. The advantage of the mediated amperometric bacterial biosensor system is its in situ application in soils. The present study demonstrated that soil pore water does not accurately reflect conditions of soil ecosystem, and that in situ bioassays are more reliable for determining the bioavailability and toxicity of heavy metals. This is the first reported use of disposable whole cell biosensors for in situ heavy metal bioavailability and toxicity assessment. The biosensor protocol developed here can be adapted to allow the incorporation of dfferent bacterial biocatalysts for applications in soil quality assessment, screening of sites for contamination ‘hot spots’, and the evaluation of soil degradation or rehabilitation from metal pollution. Mediated amperometric bacterial biosensors are not analyte specific, their response reflecting the metabolic impact of the combined chemical and physical properties of the environment to which they are exposed. In assessing the toxicity of soil samples from fields using these biosensors, it is vital to get appropriate control soil samples. The conditions of soil samples also need to be well defined. The sensitivity of the mediated amperometric whole-cell biosensors to heavy metals need to be further improved. Investigations are also required to determine how the natural conditions affect the application of the biosensor system in the field.
Affiliation:
LIRANS Institute of Research in Applied Natural Sciences
Publisher:
University of Bedfordshire
Issue Date:
May-2009
URI:
http://hdl.handle.net/10547/133551
Type:
Thesis or dissertation
Language:
en
Description:
A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of Philosophy
Appears in Collections:
PhD e-theses

Full metadata record

DC FieldValue Language
dc.contributor.authorDing, Yurongen
dc.date.accessioned2011-06-17T10:28:45Z-
dc.date.available2011-06-17T10:28:45Z-
dc.date.issued2009-05-
dc.identifier.urihttp://hdl.handle.net/10547/133551-
dc.descriptionA thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of Philosophyen
dc.description.abstractThe aim of this study was to develop a suitable monitoring protocol for mediated amperometric whole-cell biosensors for in situ assessment of heavy metals in soil. E. coli 8277, Pseudomonas 9773, Pseudomonas 9046 and Pseudomonas 8917 were screened as biosensor catalysts to select the sensitive biosensor configurations to heavy metals. A new protocol was developed for monitoring heavy metals in defined solution, soil pore water, and in situ in soil. This study also demonstrated the applications of mediated amperometric bacterial biosensors for in situ assessing the bioavailability and toxicity of heavy metals in freshly spiked soils or historically contaminated soils, and mixture toxicities of heavy metals. It was found that the biosensors incorporating selected bacterial strains were appropriately sensitive to copper, but less sensitive to Zn, Pb, and Hg, compared to Microtox assay. The advantage of the mediated amperometric bacterial biosensor system is its in situ application in soils. The present study demonstrated that soil pore water does not accurately reflect conditions of soil ecosystem, and that in situ bioassays are more reliable for determining the bioavailability and toxicity of heavy metals. This is the first reported use of disposable whole cell biosensors for in situ heavy metal bioavailability and toxicity assessment. The biosensor protocol developed here can be adapted to allow the incorporation of dfferent bacterial biocatalysts for applications in soil quality assessment, screening of sites for contamination ‘hot spots’, and the evaluation of soil degradation or rehabilitation from metal pollution. Mediated amperometric bacterial biosensors are not analyte specific, their response reflecting the metabolic impact of the combined chemical and physical properties of the environment to which they are exposed. In assessing the toxicity of soil samples from fields using these biosensors, it is vital to get appropriate control soil samples. The conditions of soil samples also need to be well defined. The sensitivity of the mediated amperometric whole-cell biosensors to heavy metals need to be further improved. Investigations are also required to determine how the natural conditions affect the application of the biosensor system in the field.en
dc.language.isoenen
dc.publisherUniversity of Bedfordshireen
dc.subjectbiosensorsen
dc.subjectheavy metalsen
dc.subjectsoilen
dc.subjecttoxicityen
dc.subjectbioavailabilityen
dc.subjectF853 Pollution Controlen
dc.titleDevelopment of a whole-cell based biosensor technique for assessment of bioavailability and toxicity of heavy metals in soilen
dc.typeThesis or dissertationen
dc.contributor.departmentLIRANS Institute of Research in Applied Natural Sciencesen
dc.type.qualificationnamePhDen
dc.type.qualificationlevelDoctoralen
dc.publisher.institutionUniversity of Bedfordshireen
This item is licensed under a Creative Commons License
Creative Commons
All Items in UOBREP are protected by copyright, with all rights reserved, unless otherwise indicated.