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An investigation into the arsenic resistance genes of Leptospirillum ferriphilum

Thesis (MSc)--University of Stellenbosch, 2005.

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Main Author: Hector, Stanton Bevan Ernest
Other Authors: Rawlings, D. E.
Format: Thesis
Language:en_ZA
Published: Stellenbosch : University of Stellenbosch 2011
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access_status_str Open Access
author Hector, Stanton Bevan Ernest
author2 Rawlings, D. E.
author_browse Hector, Stanton Bevan Ernest
Rawlings, D. E.
author_facet Rawlings, D. E.
Hector, Stanton Bevan Ernest
author_sort Hector, Stanton Bevan Ernest
collection Thesis
dc_rights_str_mv University of Stellenbosch
description Thesis (MSc)--University of Stellenbosch, 2005.
format Thesis
id oai:scholar.sun.ac.za:10019.1/16607
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:42:09.814Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2011
publishDateRange 2011
publishDateSort 2011
publisher Stellenbosch : University of Stellenbosch
publisherStr Stellenbosch : University of Stellenbosch
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source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/16607 An investigation into the arsenic resistance genes of Leptospirillum ferriphilum Hector, Stanton Bevan Ernest Rawlings, D. E. University of Stellenbosch. Faculty of Science. Dept. of Microbiology. Microorganisms -- Effect of metals on Bacterial genetics Arsenic Leptospirillum ferriphilum -- Genetics Leptospirillum ferriphilum -- Resistance to arsenic Theses -- Microbiology Dissertations -- Microbiology Thesis (MSc)--University of Stellenbosch, 2005. ENGLISH ABSTRACT: Leptospirillum ferriphilum is a moderately thermophilic, iron-oxidizing bacterium that was isolated from a continuous-flow biooxidation plant used for the recovery of gold from arsenopyrite ore concentrates. Over many years of continuous selection, L. ferriphilum and other bacteria associated with this environment developed resistance to high concentrations of arsenic. We investigated the arsenic resistance genes (ars) of Leptospirillum ferriphilum strain Fairview and compared these genes to the ars genes from other Leptospirilli. An arsenic resistance operon (ars operon) was isolated from a L. ferriphilum Fairview genebank. We discovered that this ars operon was situated in between divergently transcribed transposase (tnpA) and resolvase (tnpR) genes related to the Tn21 subfamily of transposons. Sequence analysis of this transposon ars operon indicated the presence of arsRCDAB genes and an additional CBS orf, located in between the arsA and arsB genes. The 8.5 kb L. ferriphilum transposon ars operon (TnLfArs) was shown to be present only in L. ferriphilum strain Fairview and none of the other Leptospirillum strains. The TnLfArs conferred resistance to arsenate and arsenite in an Escherichia coli ars mutant. We also showed that the TnLfArs is capable of transposition in Escherichia coli. AFRIKAANSE OPSOMMING: Leptospirillum ferriphilum, ‘n matig termofilies, yster-oksiderende bakterium, is een van `n konsortium bakterieë betrokke by die biologiese herwinning van goud uit arsenopiriet erts. Oor vele jare het die selektiewe druk, weens hoë arseen konsentrasies teenwoordig in die erts, veroorsaak dat L. ferriphilum en die ander bakteriee geassosieer met die omgewing, verhoogde vlakke van weerstandbiedendheid teen die metaal opgebou het. Die doel van die studie was om die aard van die aanpassing op die molukulere vlak vas te stel deur die gene wat in L. ferriphilum (Fairview ras) hiervoor verantwoordelik is te identifiseer en te vergelyk met die van ander Leptospirilli. `n Arseen weestandbiedendheids operon (ars operon) is met behulp van `n L. ferriphilum geen-bank geisoleer. DNA-volgorde bepaling het aangedui dat die operon arsRCDAB gene bevat, sowel as `n CBS orf, gelee tussen die arsA en arsB gene. Die hele operon is gelee tussen `n tnpR- (resolvase) en tnpA (transposase) gene wat in teenoorgestelde rigtings getranskribeer word. Hierdie gene behoort aan die Tn21 familie van transposons. Daar is gevind dat die 8.5 kb L. ferriphilum transposon wat die ars operon bevat (TnLfArs) slegs teenwoordig is in die Fairview ras van L. ferriphilum maar in geen van die ander Leptospirillum rasse nie. Die TnLfArs het weerstanbiedendheid verleen, teen beide arsenaat en arseniet, aan `n Escherichia coli arseen-sensitiewe mutant. Die vermoë van die transposon (TnLfArs) om transposisie te ondergaan is ook in E. coli bevestig. 2011-10-11T09:44:50Z 2011-10-11T09:44:50Z 2011-10 Thesis http://hdl.handle.net/10019.1/16607 en_ZA University of Stellenbosch iii, 112 leaves : ill. application/pdf Stellenbosch : University of Stellenbosch
spellingShingle Microorganisms -- Effect of metals on
Bacterial genetics
Arsenic
Leptospirillum ferriphilum -- Genetics
Leptospirillum ferriphilum -- Resistance to arsenic
Theses -- Microbiology
Dissertations -- Microbiology
Hector, Stanton Bevan Ernest
An investigation into the arsenic resistance genes of Leptospirillum ferriphilum
title An investigation into the arsenic resistance genes of Leptospirillum ferriphilum
title_full An investigation into the arsenic resistance genes of Leptospirillum ferriphilum
title_fullStr An investigation into the arsenic resistance genes of Leptospirillum ferriphilum
title_full_unstemmed An investigation into the arsenic resistance genes of Leptospirillum ferriphilum
title_short An investigation into the arsenic resistance genes of Leptospirillum ferriphilum
title_sort investigation into the arsenic resistance genes of leptospirillum ferriphilum
topic Microorganisms -- Effect of metals on
Bacterial genetics
Arsenic
Leptospirillum ferriphilum -- Genetics
Leptospirillum ferriphilum -- Resistance to arsenic
Theses -- Microbiology
Dissertations -- Microbiology
url http://hdl.handle.net/10019.1/16607
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