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Unravelling the Vitis vinifera L. cv Pinotage fermentation microbiome across the Western Cape
Thesis (MScAgric)--Stellenbosch University, 2023.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2023
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| _version_ | 1867613901963657216 |
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| access_status_str | Open Access |
| author | Blakeway, Nicole Jessie |
| author2 | Setati, Mathabatha Evodia
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| author_browse | Blakeway, Nicole Jessie Setati, Mathabatha Evodia |
| author_facet | Setati, Mathabatha Evodia
Blakeway, Nicole Jessie |
| author_sort | Blakeway, Nicole Jessie |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MScAgric)--Stellenbosch University, 2023. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/128449 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:43:30.888Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2023 |
| publishDateRange | 2023 |
| publishDateSort | 2023 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/128449 Unravelling the Vitis vinifera L. cv Pinotage fermentation microbiome across the Western Cape Blakeway, Nicole Jessie Setati, Mathabatha Evodia Stellenbosch University. Faculty of AgriSciences. Dept. of Viticulture & Oenology & Institute for Wine Biotechnology. Grapes -- South Africa -- Western Cape Wine and wine making -- Microbiology Vitis vinifera L. cv Pinotage -- South Africa -- Western Cape Grapes -- Microbiology Fermentation -- Microbiology UCTD Thesis (MScAgric)--Stellenbosch University, 2023. ENGLISH ABSTRACT: Over the past decade there has been growing interest in understanding the geographic distribution of wine fermentation microbiota due to their contribution to wine aroma and the belief that microorganisms contribute to wine terroir and therefore the distinctiveness particularly of spontaneously fermented wines. Studies conducted in many wine producing regions and on different grapevine cultivars have shown that wine fermentation microbial communities are influenced by vineyard geography, grape variety and vintage. Although South Africa is considered a major wine producing country, little is known about the microbial diversity in its vineyards. Consequently, the current study investigated the geographical distribution of the microbiota associated with Vitis vinifera L. cv Pinotage, a uniquely South African cultivar generated by crossing Hermitage and Pinot noir. Pinotage grapes were collected from 32 vineyards across 9 districts and processed following standard winemaking practices at the Stellenbosch University experimental cellar. The chemical and microbial community composition of the resulting grape must were compared. Furthermore, spontaneous fermentations were conducted, and the microbial population dynamics were monitored. The chemical compositions of the Pinotage finished wines were also analysed. Based on ARISA profiles, the bacterial communities were similar between regions and districts, and smaller differences that were found could be attributed to chance. Phylogenetic surveys based on amplicon sequencing revealed an increase in bacterial dissimilarities over distance. Vineyards were found to be mostly similar with the genera Acetobacter, Bacillus, Enterobacter, Gluconobacter, Kozakia, Pantoea, Pseudomonas and Streptomyces being the main contributors to the similarities. In contrast, ARISA data showed that fungal communities were different and displayed increasing dissimilarities over distance. Differences were found to be greater than those expected by chance. However, phylogenetic surveys showed similarities between regions and variance of vineyards with individual districts. The similarities that were found were attributed to the genera Mycosphaerella, Penicillium and Aspergillus. No significant differences were found between the yeast communities over distance, likely due to the genus Torulospora, which was in high abundance. For within vineyard analysis, blocks hosted some unique bacterial and fungal operational taxonomic units, and differences were theorised to be due to mesoclimate, and differences in harvest dates. All wines fermented to dryness, although fermentative yeasts were not found in all must samples. It was theorised that yeast species may have been inoculated in musts from the cellar equipment used or cellar environment. The bacterial and fungal dynamics were monitored at different periods in fermentation and general decline in OTUs from musts to finished wines was found. Finished wine samples were found to have no significant differences between them. Broad standard deviation in chemical samples was found and attributed to biological replicates and possible oxidation of samples. Overall, this work provides evidence for the natural microbial population associated with Pinotage musts and adds to the growing information on the microbial biogeography of grape musts. This research could inform Pinotage management practices and could help to enhance Pinotage wine distinctiveness. AFRIKAANSE OPSOMMING: Oor die afgelope dekade was daar toenemende belangstelling in die begrip van die geografiese verspreiding van wynfermentasiemikrobiota as gevolg van hul bydrae tot wynaroma en die oortuiging dat mikroörganismes bydra tot wynterroir en dus die eiesoortigheid van veral spontaan gefermenteerde wyne. Studies wat in baie wynproduserende streke en op verskillende wingerdkultivars uitgevoer is, het getoon dat wynfermentasie mikrobiese gemeenskappe deur wingerdgeografie, druifvariëteit en oesjaar beïnvloed word. Alhoewel Suid-Afrika as 'n groot wynproduserende land beskou word, is min bekend oor die mikrobiese diversiteit in sy wingerde. Gevolglik het die huidige studie die geografiese verspreiding van die mikrobiota wat met Vitis vinifera L. cv Pinotage geassosieer word, ondersoek, 'n unieke Suid-Afrikaanse kultivar wat gegenereer word deur Hermitage en Pinot noir te kruis. Pinotage druiwe is van 32 wingerde oor 9 distrikte versamel en volgens standaard wynmaakpraktyke by die Universiteit Stellenbosch eksperimentele kelder verwerk. Die chemiese en mikrobiese gemeenskapsamestelling van die gevolglike druiwemos is vergelyk. Verder is spontane fermentasies uitgevoer, en die mikrobiese populasiedinamika is gemonitor. Die chemiese samestellings van die Pinotage voltooide wyne is ook ontleed. Gebaseer op ARISA-profiele was die bakteriese gemeenskappe soortgelyk tussen streke en distrikte, en kleiner verskille wat gevind is kon aan toeval toegeskryf word. Filogenetiese opnames gebaseer op amplikonvolgordebepaling het 'n toename in bakteriese ongelykhede oor afstand aan die lig gebring. Daar is gevind dat wingerde meestal soortgelyk is met die genera Acetobacter, Bacillus, Enterobacter, Gluconobacter, Kozakia, Pantoea, Pseudomonas en Streptomyces wat die belangrikste bydraers tot die ooreenkomste was. Daarteenoor het ARISA-data getoon dat swamgemeenskappe verskillend was en toenemende verskille oor afstand vertoon. Daar is gevind dat verskille groter is as wat toevallig verwag is. Filogenetiese opnames het egter ooreenkomste tussen streke en variasie van wingerde met individuele distrikte getoon. Die ooreenkomste wat gevind is, is toegeskryf aan die genera Mycosphaerella, Penicillium en Aspergillus. Geen betekenisvolle verskille is gevind tussen die gisgemeenskappe oor afstand nie, waarskynlik as gevolg van die genus Torulospora, wat in groot oorvloed was. Vir binne wingerdontleding, het blokke 'n paar unieke bakteriese en swam operasionele taksonomiese eenhede gehuisves, en verskille is teoretiseer as gevolg van mesoklimaat, en verskille in oesdatums. Alle wyne het tot droog gegis, hoewel fermentatiewe giste nie in alle mosmonsters gevind is nie. Daar is teoretiseer dat gisspesies moontlik in most ingeënt is uit die keldertoerusting wat gebruik is of kelderomgewing. Die bakteriese en swamdinamika is tydens verskillende tydperke in fermentasie gemonitor en algemene afname in OTU's van mos tot klaarwyne is gevind. Daar is gevind dat voltooide wynmonsters geen beduidende verskille tussen hulle het nie. Breë standaardafwyking in chemiese monsters is gevind en toegeskryf aan biologiese herhalings en moontlike oksidasie van monsters. Oor die algemeen verskaf hierdie werk bewyse vir die natuurlike mikrobiese populasie wat met pinotagemos geassosieer word en dra by tot die groeiende inligting oor die mikrobiese biogeografie van druiwemos. Hierdie navorsing kan Pinotage-bestuurspraktyke inlig en kan help om Pinotage-wyn se eiesoortigheid te verbeter. Masters 2023-03-07T14:23:04Z 2023-08-30T13:10:02Z 2023-03 2023-03-07T14:23:04Z 2023-08-31T09:18:45Z 2023-03-07T14:23:04Z 2023-08-31T09:18:45Z 2023-03 Thesis https://scholar.sun.ac.za/handle/10019.1/128449 en Stellenbosch University application/pdf 12 unnumbered pages, 82 pages : illustrations, maps application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Grapes -- South Africa -- Western Cape Wine and wine making -- Microbiology Vitis vinifera L. cv Pinotage -- South Africa -- Western Cape Grapes -- Microbiology Fermentation -- Microbiology UCTD Blakeway, Nicole Jessie Unravelling the Vitis vinifera L. cv Pinotage fermentation microbiome across the Western Cape |
| title | Unravelling the Vitis vinifera L. cv Pinotage fermentation microbiome across the Western Cape |
| title_full | Unravelling the Vitis vinifera L. cv Pinotage fermentation microbiome across the Western Cape |
| title_fullStr | Unravelling the Vitis vinifera L. cv Pinotage fermentation microbiome across the Western Cape |
| title_full_unstemmed | Unravelling the Vitis vinifera L. cv Pinotage fermentation microbiome across the Western Cape |
| title_short | Unravelling the Vitis vinifera L. cv Pinotage fermentation microbiome across the Western Cape |
| title_sort | unravelling the vitis vinifera l cv pinotage fermentation microbiome across the western cape |
| topic | Grapes -- South Africa -- Western Cape Wine and wine making -- Microbiology Vitis vinifera L. cv Pinotage -- South Africa -- Western Cape Grapes -- Microbiology Fermentation -- Microbiology UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/128449 |
| work_keys_str_mv | AT blakewaynicolejessie unravellingthevitisviniferalcvpinotagefermentationmicrobiomeacrossthewesterncape |