How can fermentation be considered accurate? We need to grasp from these four levels

For example, precise temperature control: Temperature is one of the key factors affecting the fermentation process. Different fermentation strains and stages have their suitable temperature ranges. 

For example, yeast has a better fermentation effect at around 25 ℃ -30 ℃. If the temperature is too high, the yeast will become inactive, while if the temperature is too low, the fermentation rate will slow down.

In industrial fermentation, temperature sensors and automatic temperature control equipment are usually used to accurately control the fermentation temperature within a set range.

The temperature control accuracy is generally required to be within ± 0.5 ℃ or even higher to ensure the stability and consistency of fermentation.

For example, precise control of dissolved oxygen concentration: for aerobic fermentation, the supply of dissolved oxygen is crucial. Insufficient dissolved oxygen concentration can limit the growth and metabolism of microorganisms, while excessive dissolved oxygen concentration may lead to oxidative damage.

Dissolved oxygen concentration can be adjusted through methods such as ventilation rate and stirring speed, monitored in real-time using dissolved oxygen sensors, and controlled within an appropriate range. 

For example, in certain microbial fermentation processes, the dissolved oxygen concentration needs to be controlled at around 20% -30% saturation.

For example, precise control of bacterial concentration: Bacterial concentration reflects the growth of microorganisms and can be measured by methods such as optical density, dry weight, and cell counting. 

During the fermentation process, it is necessary to regularly monitor changes in bacterial concentration to understand the growth stage and rate of microorganisms.

For example, in the early stages of fermentation, the concentration of bacterial cells will gradually increase, and when it reaches a certain concentration, it may enter a stable or declining period. According to changes in bacterial concentration, fermentation conditions can be adjusted in a timely manner to ensure optimal growth and metabolism of microorganisms.

For example, precise control of metabolite concentration: The purpose of fermentation is to produce specific metabolites, so it is necessary to monitor the concentration of metabolites. Qualitative and quantitative analysis of metabolites can be performed using analytical methods such as chromatography, spectroscopy, and enzymatic analysis.

Based on the rate and concentration changes of metabolites, it is possible to determine whether the fermentation process is normal and whether fermentation conditions need to be adjusted. For example, in the process of antibiotic fermentation, it is necessary to closely monitor the production and purity of antibiotics to ensure product quality.

For example, accurately determining the endpoint of fermentation: Accurately determining the endpoint of fermentation is very important. Ending fermentation too early may lead to insufficient product yield, while ending fermentation too late may affect the quality and stability of the product.

There are various methods to determine the endpoint of fermentation, such as changes in pH value, increases in product concentration, and decreases in gas production. For example, during beer fermentation, when the pH value of the fermentation broth stabilizes within a certain range, the alcohol concentration reaches the set value, and the amount of gas produced is minimal, it can be determined that fermentation has ended.

For example, precise control of product purity: For products produced by fermentation, it is necessary to test whether their purity meets the requirements. 

For example, in the field of biopharmaceuticals, protein drugs produced by fermentation need to undergo purity testing to ensure the safety and efficacy of the drugs.

Purity testing can be performed using methods such as high-performance liquid chromatography and electrophoresis to analyze the impurity content in the product.