In order to enable the microorganisms to flourish and grow in the most suitable ph range and eventually synthesize the target metabolites. We need to strictly control the ph value in the fermentation. Therefore, fast and accurate online monitoring of value changes and timely pH regulation becomes one of the key factors for the ultimate success or failure of fermentation.
How to regulate the pH value of the laboratory fermenter during the fermentation process?
pH measurements are part of a primary cell system, which serves to convert chemical energy into electrical energy.The voltage between the positive and negative terminals of a battery is called the electrode potential.And the electrode potential is composed of a measuring electrode (indicator electrode) and a reference electrode.
The slope of the electrode response of pH, meaning that the pH electrode converts the electrode's millivolt (mV) signal into a pH value. Since the reference electrode potential is stable, this electric potential is related to the hydrogen ion activity of the measured solution, and eventually the pH value is obtained by comparing the voltage difference measured by the standard solution and dividing it by the standard buffer difference.
The pH control mainly relies on ACID and BASE pumps for acid and alkaline working operations.
Peristaltic pumps are controlled by PID：
① When the pH value is higher than the set value, the system will automatically start the ACID pump to add acid until the set value is reached.
③ When the pH value in the fermenter exceeds the optimum value, it means that the condition of the flora is starved, and then the FEED pump can be activated for replenishment.
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