Research spotlight on 'friendly' bacteria
strains of probiotic bacteria. The aim is to help food scientists
improve the safety of foods such as cheese and yoghurt and the
research will also contribute to understanding how the 'good'
bacteria work in the human gut.
Three dozen scientists from across the US will meet later this month to examine the genomes of lactic acid bacteria, the so-called 'friendly' bacteria which play a major role in cheese and yoghurt production and also have a positive effect on gut health.
The meeting at the Joint Genome Institute (JGI) next week will allow food scientists to analyse the DNA of the various strains of lactic acid bacteria, thereby enhancing preservation and safety of fermented foods.
"Besides their importance in food production, these 'probiotic' or 'good' bacteria can be beneficial in other ways - contributing to the health and balance of the intestinal tract and helping fight illness and disease," said JGI director Eddy Rubin. "Learning about the genetic makeup of probiotic bacteria can help in the prevention and treatment of a variety of gastrointestinal disorders."
As part of the US Department of Energy's Microbial Genome Programme, the JGI has completed the sequencing of the genomes of the 11 lactic acid bacteria targeted by the Lactic Acid Bacteria Genome Consortium, a group of molecular scientists from a dozen US universities. One of the bacteria, Oenococcus oeni, is especially important to wine growers because it contributes to flavour, aroma and texture and can help retard spoilage and taint in some wines.
Dr David Mills, a food microbiologist and assistant professor of viticulture and oenology at the University of California-Davis, said the bacteria under study are used in the production of $20 to $30 billion (€20.3-30.4bn) worth of fermented products per year in the United States. "Looking at the genomes will aid in finding and exploiting those genetic traits that make a better cheese, wine or sausage," Mills said. "Conversely, we can learn more about those lactic acid bacteria that spoil products, to help identify them earlier and perhaps prevent their growth and the resulting spoilage."
Mills said the meeting could shed light on the common genetic mechanisms that enable the bacteria to use sugars, nitrogen and other substances in fermentation, as well as the genetic differences that allow them to live in such "markedly different environments" as milk, wine, beer, vegetables and the human gastrointestinal tract. "We can compare the genetic plans and identify common gene sets that help us understand how they work so well in those environments," he said.
Along with the economic value of learning more about how the bacteria function, Mills said, the scientists hope to answer a number of open questions about how they evolved and where they fit on the evolutionary tree.
"To our knowledge, no one has ever sequenced such a large number of genetically related microbes before," Mills said. "This gives us an unprecedented opportunity to learn about genome evolution with a defined, related group - can we use genome information to understand how a small, related, section of the tree of life evolved?"
