Ultrasound tracks fermentation

An acoustic system developed at Pacific Northwest National Laboratory eliminates the need for laborious and costly sampling of slurries in large containers.

Fermentation-based industries, such as beer and pharmaceuticals, could benefit from the system's non-invasive, continuous and objective ‘listening’ technique in tracking microbial growth through different process phases.

In an experimental or production fermentation process, it is frequently necessary to monitor the growth of organisms within a fermentor. The typical method for doing this is a time-consuming and invasive process of collecting, diluting and counting a sample at periodic intervals.

But the researchers at PNNL have automated the process by deploying ultrasonic technology.

The system works by analysing how ultrasonic signals are scattered and absorbed within the fermentor media as a function of time. Conceptually, the acoustic system is relatively simple. It consists of either a single transducer or paired transducers placed on opposite sides of a container.