Microbial Sensors for Oxygen Limitations in Fermentors
Author Information
Author(s): Jose R. Garcia, Hyung J. Cha, Govind Rao, Mark R. Marten, William E. Bentley
Primary Institution: University of Maryland
Hypothesis
Can a new cellular oxygen sensor reveal oxygen limitations in well-mixed laboratory-scale fermentors?
Conclusion
The pNar-GFPuv plasmid allows for effective bioreactor-wide oxygen sensing, indicating that even well-mixed fermentors can have oxygen limitations affecting cell behavior.
Supporting Evidence
- Cells with one impeller showed higher GFP expression than those with four, indicating more oxygen deprivation.
- Even when dissolved oxygen levels were above 80%, cells experienced oxygen limitations due to fluid segregation.
- The GFP expression time is much longer than the mixing time, indicating an averaged effect of oxygen limitation.
Takeaway
Scientists created tiny sensors using bacteria to check if there’s enough oxygen in fermentation tanks, and found that even when it looks good, the bacteria can still be struggling for air.
Methodology
The study involved using a new oxygen-responsive plasmid in E. coli to measure oxygen levels during fermentations with different impeller configurations.
Limitations
The study did not manipulate oxygen levels to fully explore the dynamic range of the sensing cells.
Digital Object Identifier (DOI)
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