Non-Invasive Characterization of Different Saccharomyces Suspensions with Ultrasound

Area of Science:

• Biotechnology
• Process Engineering
• Analytical Chemistry

Background:

• Monitoring yeast cell count and substrate concentration is crucial for optimizing fermentation processes.
• Current methods for monitoring biological suspensions are often invasive or limited by detection issues.
• Non-invasive, real-time monitoring is needed for efficient industrial fermentation.

Purpose of the Study:

• To investigate the suitability of ultrasound measurements for characterizing yeast suspensions.
• To evaluate ultrasound's ability to monitor both the yeast cells (dispersed phase) and the fermentation medium (continuous phase).
• To compare the performance of ultrasound with three different Saccharomyces yeast strains.

Main Methods:

• Utilized ultrasound signals to analyze yeast suspensions.
• Measured ultrasound attenuation coefficient and speed of sound.
• Correlated ultrasound parameters with varying yeast concentrations (0.0-1.0 wt%) and cell counts.
• Investigated the influence of cell diameter and volume density on ultrasound attenuation.

Main Results:

• Ultrasound attenuation and speed of sound showed a linear increase with yeast concentration and cell count (R² > 0.95) for all tested yeasts.
• Ultrasound signal attenuation was influenced by yeast cell diameter and volume density.
• Speed of sound variations were partly attributed to changes in the liquid medium composition.

Conclusions:

• Ultrasound technology is effective for monitoring yeast cell concentration and characteristics in industrial fermentations.
• The findings support the development of targeted control strategies for fermentation processes using ultrasound.
• Ultrasound provides a non-invasive, real-time alternative to traditional monitoring methods.