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Screening, isolating and characterizing acetyl xylan esterase enzymes from a novel ecological niche

Thesis (MSc)--Stellenbosch University, 2015.

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Main Author: Marais, Charl
Other Authors: Kossmann, Jens
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2015
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access_status_str Open Access
author Marais, Charl
author2 Kossmann, Jens
author_browse Kossmann, Jens
Marais, Charl
author_facet Kossmann, Jens
Marais, Charl
author_sort Marais, Charl
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (MSc)--Stellenbosch University, 2015.
format Thesis
id oai:scholar.sun.ac.za:10019.1/96713
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:47:05.324Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2015
publishDateRange 2015
publishDateSort 2015
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/96713 Screening, isolating and characterizing acetyl xylan esterase enzymes from a novel ecological niche Marais, Charl Kossmann, Jens George, Gavin M. Stellenbosch University. Faculty of Agrisciences. Dept. of Genetics. Institute for Plant Biotechnology (IPB). Xylan esterase enzymes -- Characterization Biofuel production UCTD Thesis (MSc)--Stellenbosch University, 2015. ENGLISH ABSTRACT: Hemicellulose, a plant cell wall polysaccharide composed amongst other 6-carbon sugars of xylose, a 5-carbon fermentable sugar, has various side-chains which hinder breakdown by the hydrolytic enzyme xylanase. We executed a screen of a metagenomic library established from heat treated saw dust to isolate novel genes for plant cell wall esterases and isolated two clones that potentially could be utilised as acetyl xylan esterases: HEL12 and HEL37 from Citrobacter farmeri and Bacillus vallismortis respectively are confirmed short-chain acetyl xylan esterases (C2-C4) with an optimal temperature of 30°C and 35°C and pH 8.0. HEL12 (33kDa) and HEL37 (25kDa) are small, dextrous acetyl xylan esterases with HEL37: Km of 1.621mM for p-nitrophenyl acetate and Km of 3.571mM for the substrate p-nitrophenyl palmitate with a Vmax of 2.462 mMol/min/mg protein and Vmax of 0.4363 mMol/min/mg protein respectively. In addition HEL12 was active on other substrates with a Km of 1.321mM protein for p-nitrophenyl acetate and Km of 1.692mM for the substrate p-nitrophenyl butyrate with a Vmax of 3.812 and Vmax of 1.523 mMol/min/mg protein respectively. Both enzymes were assayed on various acetylated polymers including acetylated xylan to indicate their ability to hydrolyse plant lignocellulosic polymers. AFRIKAANSE OPSOMMING: Met die herwinde interisering in die energie krisis, is “herwinbare energie” vinnig besig om die nuwe modewoord te raak tussen verskeie industriële bedrywighede. Hemicellulose, ‘n plant sel wand polisakkaride opgemaak uit xilose, ‘n 5-koolstof fermenteerbare suiker, het verskillende sykettings wat ‘n hindernis veroorsaak in die hidrolase van die komponent deur xilanase ensieme. HEL12 en HEL37 van bakterieë Citrobacter farmeri en Bacillus vallismortis afsonderlik, is deel van die hidrolitiese groep van ensieme wat die hidrolisasie van ester sy-bindings op die xilaan suikerstring kataliseer. Die ensieme was primêr geassesseer vir aktiwiteit deur middel van sintetiese substraat 4-nitrofeniel asetaat. HEL12 en HEL37 was gevind om kort-ketting asetiel xilaan esterase (C2-C4) te wees, met ‘n optimale temperatuur van 30°C en 35°C afsonderlik, beide met ‘n optimale pH van 8.0. Met ‘n geskatte gewig van omtrent +- 30kDa is beide die ensieme van die kleiner meer behendige asetiel xilaan esterase, met HEL37: Km = 1.621 op 4-nitrofeniel asetaat en Km = 3.571 op substraat 4-nitrofeniel palmetaat, en Vmax = 2.462 met ‘n Vmax = 0.4363 afsonderlik, en HEL12: Km = 1.321 op 4-nitrofeniel asetaat en Km = 1.692 op sustraat 4-nitrofeniel buteraat met ‘n Vmax = 3.812 en Vmax = 1.523 afsonderlik. Masters 2015-05-20T09:26:48Z 2015-05-20T09:26:48Z 2015-03 Thesis http://hdl.handle.net/10019.1/96713 en_ZA Stellenbosch University viii, 88 pages : illustrations application/pdf application/pdf Stellenbosch : Stellenbosch University
spellingShingle Xylan esterase enzymes -- Characterization
Biofuel production
UCTD
Marais, Charl
Screening, isolating and characterizing acetyl xylan esterase enzymes from a novel ecological niche
title Screening, isolating and characterizing acetyl xylan esterase enzymes from a novel ecological niche
title_full Screening, isolating and characterizing acetyl xylan esterase enzymes from a novel ecological niche
title_fullStr Screening, isolating and characterizing acetyl xylan esterase enzymes from a novel ecological niche
title_full_unstemmed Screening, isolating and characterizing acetyl xylan esterase enzymes from a novel ecological niche
title_short Screening, isolating and characterizing acetyl xylan esterase enzymes from a novel ecological niche
title_sort screening isolating and characterizing acetyl xylan esterase enzymes from a novel ecological niche
topic Xylan esterase enzymes -- Characterization
Biofuel production
UCTD
url http://hdl.handle.net/10019.1/96713
work_keys_str_mv AT maraischarl screeningisolatingandcharacterizingacetylxylanesteraseenzymesfromanovelecologicalniche