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Energy extraction optimisation strategies of Actinobacillus succinogenes

Dissertation (MSc)--University of Pretoria, 2020.

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Other Authors: Nicol, Willie
Format: Thesis
Language:English
Published: University of Pretoria 2021
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access_status_str Open Access
author2 Nicol, Willie
author_browse Nicol, Willie
author_facet Nicol, Willie
collection Thesis
dc_rights_str_mv © 2020 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MSc)--University of Pretoria, 2020.
format Thesis
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:36:56.516Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2021
publishDateRange 2021
publishDateSort 2021
publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/79602 Energy extraction optimisation strategies of Actinobacillus succinogenes Nicol, Willie u12018423@tuks.co.za Lexow, Waldo Gideon UCTD Energy extraction Optimisation strategies Actinobacillus succinogenes Engineering, built environment and information technology theses SDG-07 Engineering, built environment and information technology theses SDG-09 Engineering, built environment and information technology theses SDG-12 Engineering, built environment and information technology theses SDG-13 Dissertation (MSc)--University of Pretoria, 2020. Actinobacillus succinogenes is known to produce the acids of acetate and formate as co-products in conjunction with succinic acid. These compounds not only divert a portion of the carbon flux away from succinic acid production, but also necessitate separation techniques that further augment production costs and, as a result, render the bio-production of succinic acid unviable. To explore methods of reducing or eliminating the production of these co-products, one needs to understand the reason for their presence in the first place. This study aimed at defining the energy boundaries that describe the fermentative behaviour of the microbe. It was found that A. succinogenes displays a clear preference for routes with higher energy extraction efficiency in the early stages of its batch-operated lifespan, subsequently replacing the routes with others of lesser efficiency as fermentation progresses. This clear observation of diminishing energy extraction efficiency supports the idea of route hierarchy, i.e. routes that are more efficient at extracting energy from the available resources are favoured over those that are less efficient. Furthermore, it suggests that accumulated environmental stresses is a likely reason for the observed shift in metabolic strategies for energy extraction. This idea is further supported by the finding of co-activation between the pyruvate dehydrogenase and pyruvic acid excretion routes. Since these have vastly different energy extraction capabilities, it is postulated that the pyruvic excretory pathway is an inherent overflow response mechanism activated to limit the amount or rate of acetic acid production. This suggests a scenario in which the co-production of pyruvic acid is holistically energetically more favourable. The prevailing postulate is that the build-up of acetic acid (and formic acid), if left unchecked, might result in a runaway energy cost effect. By limiting the external pressure of passive back-diffusion, the organism is in an energetically more favourable position since less energy need be wasted on the active export of those components. mi2026 Chemical Engineering MSc Unrestricted SDG-07: Affordable and clean energy SDG-09: Industry, innovation and infrastructure SDG-12: Responsible consumption and production SDG-13: Climate action 2021-04-22T10:33:15Z 2021-04-22T10:33:15Z 2020/09/29 2020 Dissertation Lexow, WG 2020, Energy extraction optimisation strategies of Actinobacillus succinogenes, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/79602> S2020 http://hdl.handle.net/2263/79602 en © 2020 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Energy extraction
Optimisation strategies
Actinobacillus succinogenes
Engineering, built environment and information technology theses SDG-07
Engineering, built environment and information technology theses SDG-09
Engineering, built environment and information technology theses SDG-12
Engineering, built environment and information technology theses SDG-13
Energy extraction optimisation strategies of Actinobacillus succinogenes
title Energy extraction optimisation strategies of Actinobacillus succinogenes
title_full Energy extraction optimisation strategies of Actinobacillus succinogenes
title_fullStr Energy extraction optimisation strategies of Actinobacillus succinogenes
title_full_unstemmed Energy extraction optimisation strategies of Actinobacillus succinogenes
title_short Energy extraction optimisation strategies of Actinobacillus succinogenes
title_sort energy extraction optimisation strategies of actinobacillus succinogenes
topic UCTD
Energy extraction
Optimisation strategies
Actinobacillus succinogenes
Engineering, built environment and information technology theses SDG-07
Engineering, built environment and information technology theses SDG-09
Engineering, built environment and information technology theses SDG-12
Engineering, built environment and information technology theses SDG-13
url http://hdl.handle.net/2263/79602