Research Articles (Institute for Wine Biotechnology)
Recent Submissions
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Investigating the effect of selected non-saccharomyces species on wine ecosystem function and major volatiles
(Frontiers Media, 2018-11-13)Natural alcoholic fermentation is initiated by a diverse population of several non-Saccharomyces yeast species. However, most of the species progressively die off, leaving only a few strongly fermentative species, mainly ... -
Carnitine requires choline to exert physiological effects in saccharomyces cerevisiae
(Frontiers Media, 2018-07-02)L-Carnitine is a key metabolite in the energy metabolism of eukaryotic cells, functioning as a shuttling molecule for activated acyl-residues between cellular compartments. In higher eukaryotes this function is essential, ... -
Modulation of yeast-derived volatile aromas by oleic acid and sterols
(South African Society for Enology and Viticulture, 2019)Unsaturated fatty acids and sterols are essential constituents of the yeast plasma membrane. Recently, their contribution to modulating the production of yeast-derived volatile compounds has received significant attention. ... -
Nutrient exchange of carbon and nitrogen promotes the formation of stable mutualisms between chlorella sorokiniana and saccharomyces cerevisiae under engineered synthetic growth conditions
(Frontiers Media, 2019-04)Microbial biotechnological processes can be based on single species pure cultures or on multi-species assemblages. While these assemblages can be advantageous by offering more functionalities and more resilience to changing ... -
Linking terpene synthases to sesquiterpene metabolism in grapevine flowers
(Frontiers Media, 2019)Grapevine (Vitis vinifera L.) terpene synthases (VviTPS) are responsible for the biosynthesis of terpenic volatiles. Volatile profiling of nine commercial wine cultivars showed unique cultivar-specific variation in volatile ... -
Modifying Saccharomyces cerevisiae adhesion properties regulates yeast ecosystem dynamics
(American Society for Microbiology, 2018-10-24)Physical contact between yeast species, in addition to better-understood and reported metabolic interactions, has recently been proposed to significantly impact the relative fitness of these species in cocultures. Such ... -
Research note: the use of SO2 to bind acetaldehyde in wine : sensory implications
(South African Society for Enology and Viticulture, 2018)It is thought that the formation of hydroxysulphonate when sulphur dioxide is added to wine containing free acetaldehyde negates the sensory impact of the latter compound, but little research has been done on this. Descriptive ... -
The grapevine and wine microbiome : insights from high-throughput amplicon sequencing
(Frontiers Media, 2017)From the time when microbial activity in wine fermentation was first demonstrated, the microbial ecology of the vineyard, grape, and wine has been extensively investigated using culture-based methods. However, the last ... -
Impact of grape temperature at pressing on organic acids and oenological characteristics of Méthode Cap Classique wines
(South African Society for Enology and Viticulture, 2018)Maintaining the chemical composition of a wine is essential for the wine industry. Although the sugar-acid balance of a wine is of primary sensory importance, individual acids and oenological parameters are equally important. ... -
The impact of single amino acids on growth and volatile aroma production by Saccharomyces cerevisiae strains
(Frontiers Media, 2017)Nitrogen availability and utilization by Saccharomyces cerevisiae significantly influence fermentation kinetics and the production of volatile compounds important for wine aroma. Amino acids are the most important nitrogen ... -
The role and use of non-saccharomyces yeasts in wine production
(South African Society for Enology and Viticulture, 2006)The contribution by the numerous grape-must-associated non-Saccharomyces yeasts to wine fermentation has been debated extensively. These yeasts, naturally present in all wine fermentations, are metabolically active and ... -
Understanding problem fermentations – a review
(South African Society for Enology and Viticulture, 2007)Despite advances in winemaking technology and improvements in fermentation control, problem alcoholic and malolactic fermentations remain a major oenological concern worldwide. This is due to possible depreciation of product ... -
Optimisation of the quantification of total soluble solids, ph and titratable acidity in South African grape must using Fourier transform mid-infrared spectroscopy
(South African Society for Enology and Viticulture, 2007)Calibration models for Fourier transform mid-infrared (FT-MIR) spectroscopy were developed for the simultaneous quantification of total soluble solids (TSS, measured as °Brix), pH and titratable acidity (TA, expressed as ... -
Characterisation of non-saccharomyces yeasts using different methodologies and evaluation of their compatibility with malolactic fermentation
(South African Society for Enology and Viticulture, 2017)Although Saccharomyces cerevisiae is the yeast species predominantly used for alcoholic fermentation, non-Saccharomyces yeast species are also important because they produce secondary metabolites that can contribute to the ... -
The diversity and dynamics of indigenous yeast communities in grape must from vineyards employing different agronomic practices and their influence on wine fermentation
(South African Society for Enology and Viticulture, 2015)The current study evaluated the diversity of yeast species in Cabernet Sauvignon grape must derived from three neighbouring vineyards from a similar terroir but on which significantly different management practices are ... -
Non-saccharomyces killer toxins : possible biocontrol agents against brettanomyces in wine?
(South African Society for Enology and Viticulture, 2015)Red wine spoiled by the yeast Brettanomyces bruxellensis is characterised by off-odours commonly described as horse sweat, phenolic, varnish and band-aid. The growth of this yeast in wine is traditionally controlled by ... -
Determining the impact of industrial wine yeast strains on organic acid production under white and red wine-like fermentation conditions
(South African Society for Enology and Viticulture, 2015)Organic acids are a major contributor to wine flavour and aroma. In the past, the scientific focus has mostly been on organic acids derived from grapes or on the transformation of malic acid to lactic acid by lactic acid ... -
Sequence-based analysis of the vitis vinifera L. cv cabernet sauvignon grape must mycobiome in three South African vineyards employing distinct agronomic systems
(Frontiers Media, 2015-11)Recent microbiomic research of agricultural habitats has highlighted tremendous microbial biodiversity associated with such ecosystems. Data generated in vineyards have furthermore highlighted significant regional differences ... -
3-way networks : application of hypergraphs for modelling increased complexity in comparative genomics
(PLoS, 2015-03)We present and develop the theory of 3-way networks, a type of hypergraph in which each edge models relationships between triplets of objects as opposed to pairs of objects as done by standard network models. We explore ... -
The vineyard yeast microbiome, a mixed model microbial map
(PLoS, 2012-12-26)Vineyards harbour a wide variety of microorganisms that play a pivotal role in pre- and post-harvest grape quality and will contribute significantly to the final aromatic properties of wine. The aim of the current study ...
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