Ndimba, BonganiJolly, NeilHart, Rodney Sebastian2018-04-102024-05-092018-04-102024-05-092017https://hdl.handle.net/10566/13487Philosophiae Doctor - PhD (Biotechnology)Wine yeast Saccharomyces cerevisiae and wild yeasts e.g. Torulaspora delbrueckii forms an integral part of wine production by converting relatively 'neutral' flavoured Sauvignon blanc grape must into varietal aromatic wines. Yeast derived and mediated metabolites which contribute to Sauvignon blanc wine aroma and flavour, are regulated by yeast proteins (enzymes) that are differentially expressed during the course of fermentation. Inoculation with an appropriate yeast strain can, therefore, increase commercial wines sales as resultant wines will have sought-after aromas and flavours. Likewise, inoculation with the incorrect strain can have an undesirable effect on wine quality. Subsequently, the development of yeasts for the production of varietal aromatic Sauvignon blanc with lower volatile acidity (VA) was also identified as a South African industry priority. Although genetic modification can address this, the use of genetically modified organisms (GMO) is illegal.enUniversity of the Western Cape