An in-depth study of lactic acids should help understand what causes wine spoilage.

Scientists working with the US Joint Genome Institute are researching the lactic acid bacteria responsible for malolactic fermentation in wines.

The Joint Genome Institute recently completed the sequencing of nine lactic acid bacteria. The Oenococcus oeni bacterium converts malic acid into lactic acid, contributing to the flavour, aroma and texture of wine. As such it is vital to winemakers.

‘With these genetic roadmaps in hand, our ability to study the genetics, ecology and physiology of the lactic acid bacteria in wine will be amplified tremendously,’ Dr David Mills, assistant professor of viticulture and enology at University of California Davis said.

The new research will also give scientists a better understanding of wine taints and spoilage.

‘Looking at the genomes will aid finding and exploiting those genetic traits that make a better wine,’ Mills said.

‘Conversely, we can learn more about those lactic acid bacteria that spoil products. We can help identify them earlier and perhaps prevent their growth and the resulting spoilage.’

The bacteria under study are used in the production of US$20-30bn (€20.4-30.6bn) worth of fermented products per year in the US. Along with the economic value of learning more about how they function, scientists hope to understand how they evolved and where they fit on the evolutionary tree. According to Mills, no one has ever sequenced such a large number of genetically related microbes before.

The Joint Genome Institute is one of the largest public genome sequencing centres in the world. It is managed by the University of California and operated jointly by three Department of Energy national laboratories – Lawrence Berkeley and Lawrence Livermore in California, and Los Alamos in New Mexico.

Written by Josie Butchart8 October 2002