The fermentation performance of industrial yeast strains is influenced, among other things, by their genetic composition and the nature of the fermentable sugar, availability of nitrogen, and temperature. Therefore, to manipulate the fermentation process, it is important to understand, at a molecular level, the changes occurring in the yeast cell throughout industrial fermentation processes. With this aim in mind, using two-dimensional gel electrophoresis and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF MS), we have examined the proteome of distillers yeast in an industrial context. Using yeast sampled from a local grain whisky distillery, we have prepared a detailed reference map of the proteome of distillers yeast and have examined in some detail the alterations in protein levels that occur throughout fermentation. In particular, as fermentation progresses, there is a significant increase in the levels of a variety of proteins involved in protecting against stress and nitrogen limitation. These results therefore give an insight into the stresses that yeast are exposed to in industrial fermentations and reveal some of the proteins and enzymes that are either necessary or important for efficient fermentation.

Proteomic analysis of a distilling strain of Saccharomyces cerevisiae

Characterisation of hybrid yeasts for the production of varietal Sauvignon blanc wine - A review.

139) イネ葉より分離した数種葉面菌のイネいもち病に対する発病抑制効果とInternal Transcribed Spacer (ITS)領域の解析 (平成11年度 日本植物病理学会大会)

Inductin and Characterization of Artificial Diploids from the Haploid Yeast

This paper discusses how university students were able to use sensory evaluation to determine the acceptability of new and innovative food products they developed. The report presents the individual cases where each entrepreneurial student: designed and chose a sensory evaluation method, designed their sensory questionnaire, determined their panel group size, and conducted statistical analysis on the data they collected. Since this was a pilot testing of the new and innovative food products, consumer oriented testing methods were chosen and a panel group of twenty was determined to be appropriate. Samples were presented to panelists in an appropriate test area, on an appropriate tray, at the right time and conditions (temperature) and with a well-designed scorecard/questionnaire. Data was collected from several different type of sensory evaluation tests including: hedonic ratings, food action rating, descripting rating, paired comparison and descriptive profiling. The data collected were treated statistically, for example by using two-tailed binomial test, and interpreted, thus allowing for valid information that can prove product quality and acceptability to be presented to any product development and marketing departments in any food and beverage company that may wish to adopt and produce these products. After conducting their evaluations and statistical analyses, the students determined and concluded that the products they presented to the panelists were acceptable but had room for improvement and also that the panelists had a highly positive attitude toward eating the products and even purchasing these if they were to become available on the market.

Sensory evaluation as a tool in determining acceptability of processed local agricultural products

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.

Proteomic and metabolomic characterisation of novel wine yeasts: towards the evaluation and improvements of their ability to produce aromatic sauvignon blanc wines

Rodney Sebastian Hart

Papers

Proteomic and metabolomic characterisation of novel wine yeasts: towards the evaluation and improvements of their ability to produce aromatic sauvignon blanc wines