Genes involved in arsenic transformation and resistance associated with different levels of arsenic-contaminated soils

Persistent Link:
http://hdl.handle.net/10150/610052
Title:
Genes involved in arsenic transformation and resistance associated with different levels of arsenic-contaminated soils
Author:
Cai, Lin; Liu, Guanghui; Rensing, Christopher; Wang, Gejiao
Affiliation:
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, PR China; Department of Soil, Water and Environmental Science, The University of Arizona, Tucson, AZ 85721, USA
Issue Date:
2009
Publisher:
BioMed Central
Citation:
BMC Microbiology 2009, 9:4 doi:10.1186/1471-2180-9-4
Journal:
BMC Microbiology
Rights:
© 2009 Cai et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0)
Collection Information:
This item is part of the UA Faculty Publications collection. For more information this item or other items in the UA Campus Repository, contact the University of Arizona Libraries at repository@u.library.arizona.edu.
Abstract:
BACKGROUND:Arsenic is known as a toxic metalloid, which primarily exists in inorganic form As(III) and As(V)] and can be transformed by microbial redox processes in the natural environment. As(III) is much more toxic and mobile than As(V), hence microbial arsenic redox transformation has a major impact on arsenic toxicity and mobility which can greatly influence the human health. Our main purpose was to investigate the distribution and diversity of microbial arsenite-resistant species in three different arsenic-contaminated soils, and further study the As(III) resistance levels and related functional genes of these species.RESULTS:A total of 58 arsenite-resistant bacteria were identified from soils with three different arsenic-contaminated levels. Highly arsenite-resistant bacteria (MIC > 20 mM) were only isolated from the highly arsenic-contaminated site and belonged to Acinetobacter, Agrobacterium, Arthrobacter, Comamonas, Rhodococcus, Stenotrophomonas and Pseudomonas. Five arsenite-oxidizing bacteria that belonged to Achromobacter, Agrobacterium and Pseudomonas were identified and displayed a higher average arsenite resistance level than the non-arsenite oxidizers. 5 aoxB genes encoding arsenite oxidase and 51 arsenite transporter genes 18 arsB, 12 ACR3(1) and 21 ACR3(2)] were successfully amplified from these strains using PCR with degenerate primers. The aoxB genes were specific for the arsenite-oxidizing bacteria. Strains containing both an arsenite oxidase gene (aoxB) and an arsenite transporter gene (ACR3 or arsB) displayed a higher average arsenite resistance level than those possessing an arsenite transporter gene only. Horizontal transfer of ACR3(2) and arsB appeared to have occurred in strains that were primarily isolated from the highly arsenic-contaminated soil.CONCLUSION:Soils with long-term arsenic contamination may result in the evolution of highly diverse arsenite-resistant bacteria and such diversity was probably caused in part by horizontal gene transfer events. Bacteria capable of both arsenite oxidation and arsenite efflux mechanisms had an elevated arsenite resistance level.
EISSN:
1471-2180
DOI:
10.1186/1471-2180-9-4
Version:
Final published version
Additional Links:
http://www.biomedcentral.com/1471-2180/9/4

Full metadata record

DC FieldValue Language
dc.contributor.authorCai, Linen
dc.contributor.authorLiu, Guanghuien
dc.contributor.authorRensing, Christopheren
dc.contributor.authorWang, Gejiaoen
dc.date.accessioned2016-05-20T08:57:28Z-
dc.date.available2016-05-20T08:57:28Z-
dc.date.issued2009en
dc.identifier.citationBMC Microbiology 2009, 9:4 doi:10.1186/1471-2180-9-4en
dc.identifier.doi10.1186/1471-2180-9-4en
dc.identifier.urihttp://hdl.handle.net/10150/610052-
dc.description.abstractBACKGROUND:Arsenic is known as a toxic metalloid, which primarily exists in inorganic form As(III) and As(V)] and can be transformed by microbial redox processes in the natural environment. As(III) is much more toxic and mobile than As(V), hence microbial arsenic redox transformation has a major impact on arsenic toxicity and mobility which can greatly influence the human health. Our main purpose was to investigate the distribution and diversity of microbial arsenite-resistant species in three different arsenic-contaminated soils, and further study the As(III) resistance levels and related functional genes of these species.RESULTS:A total of 58 arsenite-resistant bacteria were identified from soils with three different arsenic-contaminated levels. Highly arsenite-resistant bacteria (MIC > 20 mM) were only isolated from the highly arsenic-contaminated site and belonged to Acinetobacter, Agrobacterium, Arthrobacter, Comamonas, Rhodococcus, Stenotrophomonas and Pseudomonas. Five arsenite-oxidizing bacteria that belonged to Achromobacter, Agrobacterium and Pseudomonas were identified and displayed a higher average arsenite resistance level than the non-arsenite oxidizers. 5 aoxB genes encoding arsenite oxidase and 51 arsenite transporter genes 18 arsB, 12 ACR3(1) and 21 ACR3(2)] were successfully amplified from these strains using PCR with degenerate primers. The aoxB genes were specific for the arsenite-oxidizing bacteria. Strains containing both an arsenite oxidase gene (aoxB) and an arsenite transporter gene (ACR3 or arsB) displayed a higher average arsenite resistance level than those possessing an arsenite transporter gene only. Horizontal transfer of ACR3(2) and arsB appeared to have occurred in strains that were primarily isolated from the highly arsenic-contaminated soil.CONCLUSION:Soils with long-term arsenic contamination may result in the evolution of highly diverse arsenite-resistant bacteria and such diversity was probably caused in part by horizontal gene transfer events. Bacteria capable of both arsenite oxidation and arsenite efflux mechanisms had an elevated arsenite resistance level.en
dc.language.isoenen
dc.publisherBioMed Centralen
dc.relation.urlhttp://www.biomedcentral.com/1471-2180/9/4en
dc.rights© 2009 Cai et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0)en
dc.titleGenes involved in arsenic transformation and resistance associated with different levels of arsenic-contaminated soilsen
dc.typeArticleen
dc.identifier.eissn1471-2180en
dc.contributor.departmentState Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, PR Chinaen
dc.contributor.departmentDepartment of Soil, Water and Environmental Science, The University of Arizona, Tucson, AZ 85721, USAen
dc.identifier.journalBMC Microbiologyen
dc.description.collectioninformationThis item is part of the UA Faculty Publications collection. For more information this item or other items in the UA Campus Repository, contact the University of Arizona Libraries at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
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