Online monitoring and control

Types of biological reactions in bioreactors
Aerobic reaction: A process that requires oxygen for metabolism, such as the cultivation of most bacteria, yeast, etc. In this process, microorganisms absorb oxygen to perform respiration and decompose organic matter into carbon dioxide and water.
Anaerobic reaction: A process that does not require oxygen, such as some microorganisms decomposing sugars to produce gases (such as methane, ethanol, etc.) under anaerobic conditions. This reaction is often used in the production of biogas and the synthesis of certain biochemicals.
Cell culture: Used for large-scale cultivation of animal cells or plant cells for the production of vaccines, monoclonal antibodies, recombinant proteins and other biological products.

Key control factors of reactor principle
Dissolved oxygen (DO): It is necessary for the metabolism of microorganisms or cells. It is necessary to ensure sufficient oxygen solubility in the reaction solution.
pH value: It affects the metabolic activity of microorganisms or cells. Too high or too low pH value will inhibit growth or affect product synthesis.
Temperature: Different microorganisms or cells have optimal growth temperatures. Too high or too low pH value will affect their growth and metabolic efficiency.
Culture medium composition: It provides the carbon source, nitrogen source, minerals and other nutrients required by microorganisms or cells.
Reaction time: Different biological reactions have different reaction times. Too short or too long reaction time will affect the final product yield.

Basic components of bioreactors
Reaction vessel The main part, usually made of stainless steel or glass, with a volume ranging from a few liters at laboratory level to thousands of liters at industrial level.
Stirring system: used to mix culture medium, gas (such as oxygen) and microorganisms or cells to ensure uniform reaction. It can be mechanical stirring or airlift stirring.
Temperature control system: Temperature adjustment through jacket or built-in pipes to ensure the stability of the reaction environment.
Gas supply system: Provide oxygen to microorganisms or cells, usually using air or pure oxygen supply, while controlling gas flow.
pH control system: Maintain the pH value of the reaction environment through acid-base adjustment, usually with acid (such as HCl) or alkali (such as NaOH).
Exhaust system: Remove gases or steam generated in the reaction to avoid excessive pressure or accumulation of harmful gases.
Sampling and control system: used to monitor and collect samples in the reaction solution in real time to ensure that various parameters (such as dissolved oxygen, pH, temperature, pressure, etc.) remain within the optimal range.

Classification of bioreactors
By stirring method:Mechanical stirring reactor: stirring the liquid through impeller or stirring paddle, suitable for reactions requiring high shear force.
Gaslift reactor: stirring through the flow of bubbles generated by rising gas, suitable for relatively mild stirring conditions.
By gas supply method:Open reactor: gas and liquid can be exchanged, suitable for fermentation processes with high oxygen demand.
Closed reactor: usually used for cell culture or drug production to avoid external contamination.
By scale:Laboratory bioreactor: capacity ranges from a few liters to tens of liters, usually used for research and development and small-scale production.
Industrial bioreactor: capacity ranges from hundreds of liters to thousands of liters, suitable for large-scale production.
Application areas of bioreactors
Biotechnology:Used for cell culture, protein, vaccine and antibody production.
Food and beverages:Production of fermented foods such as yogurt, beer, soy sauce, vinegar, etc.
Environmental protection:Used for wastewater treatment and sludge treatment, using microorganisms to degrade harmful substances.
Bioenergy:Used for the production of biofuels such as ethanol, biogas, etc.
Cell culture and genetic engineering:Used for large-scale cultivation of cells or microorganisms to produce specific chemicals or genetically engineered products.

Key control parameters
Temperature: Different microorganisms or cells have different temperature requirements, and temperature control is crucial to the reaction effect.
Dissolved oxygen: Especially in aerobic fermentation, adequate oxygen supply is the key to ensure microbial growth and metabolism.
pH: Most microorganisms grow best within a specific pH range, and pH stability is crucial to the fermentation process.
Stirring speed and gas flow: These factors directly affect the gas dissolution efficiency and the uniformity of the culture medium.

Development trend of bioreactors
With the continuous advancement of technology, the design of bioreactors has been continuously optimized:
Automation and digital control: More and more bioreactors use advanced sensors and automated control systems to monitor and adjust various parameters in real time and improve production efficiency.
Single-use (SUS) reactors: Especially in the field of biopharmaceuticals, the use of disposable reactors can avoid the complex steps of cleaning and sterilization, and improve production flexibility and efficiency.
Multistage reactors: In order to improve the yield and quality of products, many industrial applications have begun to use multistage reactors for step-by-step cultivation and reaction.