Sequencing the genomes of hundreds of strains of the wine yeast S. cerevisiae has revealed little genetic diversity and high levels of inbreeding. In many cases, yeast strains sold by different companies were almost genetically identical. The results, published in the April issue of G3: Genes|Genomes|Genetics, suggest winemakers attempting to develop improved wine yeasts will need to look to creating hybrids with more exotic strains.
“Our results show that only a limited branch of the yeast evolutionary tree is currently used in winemaking,” said lead author Anthony Borneman of the Australian Wine Research Institute.
Yeast contributes to the flavors of wine and may even provide a component of a wine’s “terroir” – the local conditions that give a wine its unique flavor. Traditionally, wine has been fermented by naturally occurring yeast, but this can deliver inconsistent results from vintage to vintage. To yield more predictable results, most winemakers use pure active dried yeast starter strains that have been produced by commercial suppliers.
N.C. Science Festival: Upcoming highlights
The statewide celebration continues through April 24. For a full calendar of events, go to www.ncsciencefestival.org.
Among the upcoming events in our area: “When Giant Snakes Invade Your Country.” From 10 to 11:30 a.m. Tuesday at the Charlotte-Mecklenburg Library’s Cornelius branch, Davidson College biology professor Michael Dorcas will discuss the ecology of invasive pythons, what risk they pose and what impact they are having on our natural ecosystem. Registration recommended. Details: www.cmlibrary.org.
Among the upcoming events in our area: “Earth Fair on the Brickyard.” From 10 a.m. to 2 p.m. Wednesday at the N.C. State Brickyard, dozens of exhibits and demonstrations will foster ideas on how you can help our planet. Admission: free. Details: https://sustainability.ncsu.edu/get-involved/events/earth-day.
Bacteria-powered batteries in the future?
Dutch scientists have found success in developing a rechargeable battery driven by bacteria.
Solar, wind and other renewable energy sources are gaining ground as nations work to lower greenhouse gas emissions and reliance on petroleum. But sunlight and wind are not constant, so consumers can’t count on them 24-7. Storing energy can make renewables more reliable, but current technologies such as lithium-ion batteries are limited by safety issues, high costs and other factors.
The scientists from Wageningen University and the Wetsus Institute combined two separate microbial energy systems: One that uses bacteria to form acetate from electricity and one to convert the produced acetate back into electricity. They successfully charged the battery over a 16-hour period and discharged it over the next eight hours, mimicking the day-night pattern typical for solar energy production. They repeated this cycle 15 times in as many days. With further optimization, they say the energy density of the microbial battery could be competitive with conventional technologies.
Their report appears in the journal Environmental Science & Technology Letters.