Two early successes from incubator trial

A trial program to support new wine sector research, particularly by early career researchers, is showing great potential.

Five short-term projects were identified in 2014 to receive seed funding as part of a pilot Incubator Initiative at the University of Adelaide. Two have now been completed, with promising results.

‘We asked the university how best to assist early career researchers and they came forward with a series of good ideas’, said Wine Australia Senior R&D Program Manager Keith Hayes. ‘Each was for a 12-month project that would hopefully lay the groundwork for a future larger study.’

In one completed project, Dr Ashlea Doolette, a Research Fellow in the School of Agriculture, Food and Wine who specialises in soil science, investigated the feasibility of providing much needed phosphorus to vineyard soil by reusing the vineyard’s own by-products, rather than adding fertiliser.

‘I had already investigated a number of different systems, particularly in broadacre cropping, but the vineyard is unique because there is the potential to close the phosphorus loop’, she said.

In many crops, particularly grains, a great deal of phosphorus is lost from the system because it is contained in the final harvested product. However, with wine grapes much of the phosphorus is found in leaves and prunings, and what finds its way to the fruit is largely in the skins and stalks rather than the juice and thus can be returned to the vineyard as grape marc.

Dr Doolette’s research set out to determine the amount and chemical state of the phosphorous in senesced leaves, prunings and marc.

In the first phase she analysed prunings from nine vineyards in the Barossa Valley during vine dormancy. The second involved analysing grapevine biomass from three sites throughout the growing season and different sources of grape marc. In all she visited each site five times and says everyone involved ‘learned a lot from each other’.

The research findings give us the clearest picture yet of how phosphorous transforms in vines. The next stage would be to get more comprehensive knowledge of each process and, in particular, to understand the transformations that occur when the plant biomass is added to the soil and how quickly phosphorous might be released.

The second project, carried out by wine microbiologists Drs Michelle Walker and Tommaso Liccioli, focused on identifying and characterising the genes in yeast that can affect the colour of red wines.

It is well known that different yeast strains can influence colour, but we don’t yet understand which strains do what and why. And pinning that down is tricky as there are thousands of genes in each genome and thus a complex network of interactions.

As a first step, Drs Walker and Liccioli set out to determine which regions of the genome are linked to colour change. To do this they analysed 96 hybrid wine yeasts, evaluated their fermentation performance in synthetic red juice and subsequent impact on the resultant ‘wine’, then correlated their data against genome sequences developed by researchers at the University of Auckland.

More than 300 individual small wine samples were created and had to be monitored 2 or 3 times a day. This allowed the researchers to make the first large-scale use of an automated fermentation platform known as the Tee-Bot, which was created at the University with support from the then GWRDC. It passed with flying colours.

A great deal of specific data from the project is still being analysed, but it has clearly identified two specific regions of the genome that are linked to colour change.

This creates the platform for researchers to make a more detailed characterisation of the genes included in that area of the genome. The potential is to be able to identify new ‘sector ready’ candidate yeast strains that can be cost-effectively used by winemakers to influence wine colour.