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The diversity of polyketides in the South Atlantic and Southern Ocean

Thesis (PhD (Genetics))--University of Pretoria, 2023.

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Other Authors: Makhalanyane, Thulani Peter
Format: Thesis
Language:English
Published: University of Pretoria 2024
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access_status_str Open Access
author2 Makhalanyane, Thulani Peter
author_browse Makhalanyane, Thulani Peter
author_facet Makhalanyane, Thulani Peter
collection Thesis
dc_rights_str_mv © 2023 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 Thesis (PhD (Genetics))--University of Pretoria, 2023.
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:39:52.104Z
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provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2024
publishDateRange 2024
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/94614 The diversity of polyketides in the South Atlantic and Southern Ocean Makhalanyane, Thulani Peter u18372008@tuks.co.za Bezuidt, Oliver Makinde, Oluwatayo Ayotunde UCTD Natural products Ketosynthases Biosynthetic gene cluster Polyketides SAR 324 Sustainable Development Goals (SDGs) SDG-03: Good health and well-being Natural and agricultural sciences theses SDG-03 Thesis (PhD (Genetics))--University of Pretoria, 2023. Nature has long provided valuable pharmaceuticals, with many effective antibiotics originating from soil and plants. Yet, rising antibiotic resistance and repeated rediscovery of known compounds have redirected natural product drug discovery toward the ocean. Previous studies have shown that the extreme and oligotrophic environment substantially produce novel compounds. The significant pharmaceutical value of polyketides has sparked extensive research into their biosynthesis. The bulk of these studies have focused on the diversity of polyketides in an oligotrophic ocean, limited in iron and nitrogen, interpreting and understanding their role to the microbial community, by harnessing the available metagenomic tools. The knowledge deficit is especially true of South Atlantic Ocean (SAO) and Southern Ocean (SO), given that they are largely under sampled and pristine respectively. To reduce this knowledge deficit, we established a broad scale analysis of the SAO euphotic zone. We thereafter assessed the diversity of polyketide in the euphotic zone of SAO. We further assessed the role viruses play in the propagation of polyketides. The analysis was carried out using the contextualize approach designed due to the continuous increase of metadata in databases. We further assessed the efficacy of the approach. Our analysis revealed there is high diversity of polyketides in the euphotic zone of SAO, with the majority encoding arylpolyene pathway suggesting its role in photo-protection. Most of the identified polyketides had low similarity to known BGCs, suggesting substantial functional novelty. The result also suggested virus may be playing a role in the propagation of the abundant polyketide type. To elucidate the biosynthetic potential across the ocean depths, samples were taken from the epipelagic, mesopelagic and bathypelagic zones of the SO, in two seasons (Spring and Winter). Using metagenome-assembled genome approach, a total of 21 BGC types were recovered with at least 8 different types of BGC in each zone. The highest diversity was observed in the bathypelagic zones of the two seasons. We observed terpene and PUFA to be the most abundant in the environment and are thought to play important roles in the ecosystem function. Interestingly, we discovered SAR324 as the most biosynthetically diverse microbe in SO. Taken together, our findings substantially broaden insights regarding the diversity of polyketides in SAO and SO communities. We reveal how the continuous increase in metadata in databases can be harnessed for prospecting. These analyses demonstrate that the bathypelagic zone of SO harbours more diverse BGC types. The insights generated from the study provide an important basis for prospective researchers about the SAO and SO’s biosynthetic potentials and ability to produce different specialized metabolites in different zones. In addition, the MAGs generated will fill some phylogenetic gaps in the available genome collection, making them useful for inferring details about microbial phylogenetic relationships. Adekunle Ajasin Universsity TETFund, SANAP, LeapMicroBio4IR initiative Biochemistry, Genetics and Microbiology (BGM) PhD (Genetics) Restricted Faculty of Natural and Agricultural Sciences 2024-02-14T13:23:57Z 2024-02-14T13:23:57Z 2024-04-01 2023-09-01 Thesis * A2024 http://hdl.handle.net/2263/94614 10.25403/UPresearchdata.25218383 en © 2023 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
Natural products
Ketosynthases
Biosynthetic gene cluster
Polyketides
SAR 324
Sustainable Development Goals (SDGs)
SDG-03: Good health and well-being
Natural and agricultural sciences theses SDG-03
The diversity of polyketides in the South Atlantic and Southern Ocean
title The diversity of polyketides in the South Atlantic and Southern Ocean
title_full The diversity of polyketides in the South Atlantic and Southern Ocean
title_fullStr The diversity of polyketides in the South Atlantic and Southern Ocean
title_full_unstemmed The diversity of polyketides in the South Atlantic and Southern Ocean
title_short The diversity of polyketides in the South Atlantic and Southern Ocean
title_sort diversity of polyketides in the south atlantic and southern ocean
topic UCTD
Natural products
Ketosynthases
Biosynthetic gene cluster
Polyketides
SAR 324
Sustainable Development Goals (SDGs)
SDG-03: Good health and well-being
Natural and agricultural sciences theses SDG-03
url http://hdl.handle.net/2263/94614