Researchers in Israel have developed a new biological sensor that can detect wine spoilage at an early stage, potentially saving producers and consumers from costly losses.
Wine spoilage is often caused by the buildup of acetic acid, the compound responsible for vinegar-like smells and sour flavors. Once acetic acid levels rise, the fermentation process can stall and the wine may become undrinkable. Current methods for measuring acetic acid rely on techniques like gas chromatography and liquid chromatography, which can be expensive and slow.
The researchers’ response to this problem was to create a living biosensor made from engineered bacteria that glows in response to acetic acid. The system uses a natural bacterial regulator called YwbIR, originally found in Bacillus subtilis, which—once transcribed in the biosensor—activates a light-producing gene when it detects acetic acid. When acetic acid is present, the biosensor emits a measurable luminescent signal.
According to the paper published in Microbial Biotechnology, the biosensor showed a strong and linear response to acetic acid levels between 0 and 1 gram per liter. This range is critical for winemakers, as spoilage typically begins when levels reach approximately 0.7 grams per liter. At these spoilage-relevant concentrations, the signal increased by 5 to 8 times, providing a clear warning long before the wine becomes undrinkable.
One of the most important breakthroughs is that the sensor works not only in liquid, but also in the air above the wine. This means it can detect volatile acetic acid in the headspace of a wine bottle or fermentation tank without opening it.
In tests with commercial red and white wines, the biosensor successfully distinguished normal wine from wine that had been artificially spoiled by added acetic acid, producing a clear increase in light output within two hours.
Acetic acid is an important indicator in many fermentation-based industries beyond winemaking, including food production and biofuels. It is also emerging as a biomarker for certain diseases, meaning future versions of the biosensor could potentially be adapted for a wide variety of applications, including non-invasive medical diagnostics like breath analysis.
Data from Hebrew University of Jerusalem