Scientists have developed a glow-in-the-dark biosensor that could revolutionize wine quality control by detecting spoilage in real time — even in high-alcohol wines and without opening fermentation tanks, TPS-IL reported citing the Hebrew University of Jerusalem. The living sensor, made from engineered bacteria, lights up when it senses acetic acid, the compound responsible for sour, vinegar-like flavors, giving winemakers an early warning before fermentation stalls or flavors are ruined.

The work was led by PhD student Yulia Melnik-Kesler under the guidance of Prof. Yael Helman, in collaboration with Prof. Oded Shoseyov. Their study, published in the peer-reviewed journal Microbial Biotechnology, demonstrates a simpler, lower-cost alternative to traditional lab testing, which relies on gas and liquid chromatography and can be slow, expensive, and disruptive to the fermentation process.

“Wine spoilage is often caused by the buildup of acetic acid, which not only produces off-flavors but can also stall fermentation, rendering wine undrinkable,” said Prof. Helman. “This system allows us to detect acetic acid in real time, without complicated equipment or sample processing. It opens the door to affordable, on-site monitoring of fermentation quality and, in the future, may even support medical diagnostics based on volatile biomarkers.”

The biosensor works by using a natural bacterial regulator called YwbIR, originally found in Bacillus subtilis. When acetic acid is detected, the regulator triggers a light-producing gene, causing the bacteria to glow. In laboratory tests, the sensor exhibited a strong, linear response to acetic acid concentrations between 0 and 1 gram per liter — a range that is critical for winemakers, as spoilage typically begins around 0.7 grams per liter. At spoilage-relevant levels, the sensor’s luminescence increased five- to eight-fold, providing a clear early warning before the wine becomes undrinkable.

One of the key innovations is the sensor’s ability to detect acetic acid not only in liquid wine but also in the air above it. This allows winemakers to monitor the headspace of fermentation tanks without opening them, reducing the risk of contamination. Tests with commercial red and white wines showed the biosensor could easily distinguish normal wine from samples artificially spoiled with added acetic acid, producing a clear increase in light output within two hours.

The system also remains reliable in high-alcohol environments, functioning accurately in wines with alcohol content up to 14.5 percent, a level that typically interferes with conventional detection methods.

Beyond winemaking, the researchers see broader applications for the biosensor across fermentation-based industries, medical diagnostics, and laboratory research.

It could help prevent spoilage and optimize production in foods such as vinegar, kombucha, and soy sauce, as well as in biofuel fermentation processes. Future iterations may also be adapted to detect volatile biomarkers in breath analysis.

“This approach could strengthen quality control across multiple industries while reducing costs and the need for complex laboratory equipment,” said Melnik-Kesler. “It’s an exciting step forward for both food science and potentially human health.”