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Identification and biochemical characterisation of an aryl β-glucosidase isolated from a cellulose-acetate rich environment via a functional metagenomic approach

Thesis (MScAgric)--Stellenbosch University, 2018.

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Main Author: Pieters, Janto
Other Authors: Peters, Shaun W.
Format: Thesis
Language:English
Published: Stellenbosch : Stellenbosch University 2018
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access_status_str Open Access
author Pieters, Janto
author2 Peters, Shaun W.
author_browse Peters, Shaun W.
Pieters, Janto
author_facet Peters, Shaun W.
Pieters, Janto
author_sort Pieters, Janto
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (MScAgric)--Stellenbosch University, 2018.
format Thesis
id oai:scholar.sun.ac.za:10019.1/105187
institution Stellenbosch University (South Africa)
language English
last_indexed 2026-06-10T12:44:27.789Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2018
publishDateRange 2018
publishDateSort 2018
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/105187 Identification and biochemical characterisation of an aryl β-glucosidase isolated from a cellulose-acetate rich environment via a functional metagenomic approach Pieters, Janto Peters, Shaun W. Loedolff, Bianke Kossmann, Jens Stellenbosch University. Faculty of AgriSciences. Dept. of Genetics. Metagenomics Glucosidases Aryl-beta-glucosides UCTD Cellulose acetate Genes -- Isolation Thesis (MScAgric)--Stellenbosch University, 2018. ENGLISH ABSTRACT: Functional metagenomics has established itself as an indispensable tool in the search for novel genes by accessing the genetic information of previously unculturable microbes. These novel genes are commonly identified by assessing their function through qualitative observations of their general biochemical activities, prior to nucleic acid sequencing. In this study, a fosmid library was created from a cellulose-acetate rich environment (cigarette waste bin) and functionally screened for cellulose degrading and deacetylation enzymes. Here we report on the identification of a novel aryl-β-glucosidase identified from this library. Following plate based functional screening, one putative β-glucosidase was identified (BG4). Next generation sequencing of the 40 Kb fosmid insert identified an open reading frame (ORF) which, contained two distinct glycosyl hydrolase family one domains. The BG4 coding ORF was isolated, cloned into the pSF-OXB20-NH2-10HIS-EKT bacterial expression vector and heterologously expressed in E. coli. While BG4 showed selective hydrolytic activity to β-1,4-glucosidic bonds it displays a natural substrate specificity only to aryl-β-glucosides including arbutin, esculin hydrate, gensitin and salicin. It was most active on esculin hydrate (Km= 5.15 mM, Vmax= 0.28 µmol glucose.min-1 ) and showed a temperature and pH optimum of 40 °C and pH 6. The BG4 activity was stimulated by the presence of manganese chloride and ethyl acetate and inhibited by detergents (SDS, glycerol and Triton X-100) and glucose concentrations exceeding 1.5 mM. The specificity and high activity of BG4 towards aryl-β-glucosides could make it applicable in medical industries to release the biological potent aglycone moiety for glycosylated precursors. AFRIKAANSE OPSOMMING: Funksionele metagenomika is ‘n onontbreeklike tegniek in die soektog na onbekende gene omdat dit die gentiese inligting van onkweekbare mikrobes beskikbaar stel. Die gene word geïdentifiseer deur kwalitatiewe obserwasie van funksie voordat DNS volgorde beplaing gedoen word. In die studie is ‘n funksionele metagenomiese biblioteek is gemaak vanaf DNS geïsoleer uit ‘n selluloseasetaat ryk omgewing (sigarette stompie asdrom). Dit is daarna geëvalueer vir die teenwoordigheid van sellulose degraderende en deasetilerende gene. Hierdeur is ‘n voorlopige β-glukosidase (BG4) geïdentifiseer. Volgorde bepaling van BG4 fosmid het ‘n moontlike β-glukosidase oopleesraam geïdentifiseer. Die oopleesraam is daarna gekloneer in pSF-OXB20-NH2-10HIS-EKT bakterïele proteïn uitdrukkings vektor wat daarna in E. coli getransformeer is om BG4 te produseer. BG4 het selektiewe hidrolitiese aktiwiteit getoon op β-1,4-glukosiede verbindings en was selektief aktief op ariel-β-glukosied substrate wat arbutin, esculin hidraat, gensitin en salicin insluit. BG4 was mees aktief op esculin hidraat (Km= 5.15 mM, Vmax= 0.28 µmol glucose.min-1 ) en het optimale aktiwiteit getoon by pH 6 en 40 °C. BG4 akiwiteit was gesimuleer deur mangaan chloried en etielasetaat en sterk geïnhibeer deur SDS en glukose bo 1.5 mM. Die hoë aktiwiteit en spesifisiteit van BG4 teenoor ariel-β-glukosiede verleen dit aan moonltike toepassing vir die vrystelling van biologiese aktiewe molekules vanaf hulle onaktiewe, geglukosiseerde voorlopers. Masters 2018-11-27T09:23:21Z 2018-12-10T06:36:01Z 2018-11-27T09:23:21Z 2018-12-10T06:36:01Z 2018-12 Thesis http://hdl.handle.net/10019.1/105187 en Stellenbosch University xi, 62 leaves : illustrations (some color) application/pdf Stellenbosch : Stellenbosch University
spellingShingle Metagenomics
Glucosidases
Aryl-beta-glucosides
UCTD
Cellulose acetate
Genes -- Isolation
Pieters, Janto
Identification and biochemical characterisation of an aryl β-glucosidase isolated from a cellulose-acetate rich environment via a functional metagenomic approach
title Identification and biochemical characterisation of an aryl β-glucosidase isolated from a cellulose-acetate rich environment via a functional metagenomic approach
title_full Identification and biochemical characterisation of an aryl β-glucosidase isolated from a cellulose-acetate rich environment via a functional metagenomic approach
title_fullStr Identification and biochemical characterisation of an aryl β-glucosidase isolated from a cellulose-acetate rich environment via a functional metagenomic approach
title_full_unstemmed Identification and biochemical characterisation of an aryl β-glucosidase isolated from a cellulose-acetate rich environment via a functional metagenomic approach
title_short Identification and biochemical characterisation of an aryl β-glucosidase isolated from a cellulose-acetate rich environment via a functional metagenomic approach
title_sort identification and biochemical characterisation of an aryl β glucosidase isolated from a cellulose acetate rich environment via a functional metagenomic approach
topic Metagenomics
Glucosidases
Aryl-beta-glucosides
UCTD
Cellulose acetate
Genes -- Isolation
url http://hdl.handle.net/10019.1/105187
work_keys_str_mv AT pietersjanto identificationandbiochemicalcharacterisationofanarylbglucosidaseisolatedfromacelluloseacetaterichenvironmentviaafunctionalmetagenomicapproach