13.1
Projeto de Bioreator e Sistema Operacional
Biorreatores são embarcações projetadas para cultivar microrganismos sob condições controladas para bioprocessamento industrial. Eles mantêm a esteril…
Um biorreator é um recipiente usado para cultivar microrganismos sob condições controladas para produzir um produto biológico, minimizando a contaminação da cultura e do produto final.
O biorreator industrial mais comumente utilizado é o biorreator batch de tanque agitado e aerado.
Normalmente, é feito de aço inoxidável. Além disso, inclui uma linha de transferência e uma porta de inoculo para introdução de culturas, além de óculos para visão e luz para observação.
O furo de carga é usado para adicionar materiais, como tampões, nutrientes ou antibióticos, enquanto o vapor e a camisa d'água ajudam a regular a temperatura. Além disso, há um escapamento de ar para liberar gases.
Outros componentes do biorreator são defletores para mistura aprimorada e um impulsor, que auxilia na agitação uniforme. Uma placa de sparger introduz ar ou gás para ajudar na aeração, enquanto uma saída na parte inferior permite que o produto seja drenado ou colhido.
Para evitar contaminação, os biorreatores são totalmente soldados, com superfícies internas lisas e juntas não porosas em todas as juntas.
Os biorreatores também são equipados com sensores para monitorar pH, temperatura e oxigênio dissolvido, garantindo produtividade ideal.
View the full transcript and gain access to JoVE Core videos
Q1: What is the primary purpose of a bioreactor in industrial microbiology?
A bioreactor is a vessel designed to culture microorganisms under controlled conditions to produce biological products while minimizing contamination. It maintains precise regulation of pH, temperature, oxygen, and nutrient levels to optimize microbial growth and metabolite production for industrial bioprocessing applications.
Q2: Why is stainless steel the preferred material for large-scale bioreactors?
Stainless steel is preferred for large-scale bioreactors because it withstands steam sterilization and high operating pressures while ensuring sterility and corrosion resistance. It minimizes the risk of introducing contaminants or toxic leachables into the fermentation medium, making it ideal for maintaining product quality and mechanical strength.
Q3: How do baffles and impellers contribute to bioreactor performance?
Baffles enhance mixing efficiency within the bioreactor vessel, while impellers aid in uniform stirring of the culture medium. Together, these components ensure consistent distribution of nutrients, oxygen, and microorganisms throughout the fermentation broth, promoting optimal microbial growth and product formation.
Q4: What role do sensors play in maintaining bioreactor control?
Bioreactors are equipped with sensors to continuously monitor pH, temperature, and dissolved oxygen levels. These measurements ensure optimal productivity by allowing real-time adjustments to fermentation conditions, preventing contamination, and maintaining the precise environmental parameters required for efficient microbial growth and product synthesis.
Q5: How do bioreactors prevent contamination during fermentation?
Bioreactors prevent contamination through full welding with smooth, crevice-free internal surfaces and non-porous gaskets at all joints. These design features eliminate sites where contaminants could harbor. Additionally, steam and water jackets support sterilization, while the sealed vessel design protects the culture from external microbial invasion.
Q6: What are the key operational modes for bioreactor fermentation?
Bioreactors operate in three primary modes: batch, fed-batch, or continuous culture. Batch mode involves one-time inoculation and harvest, fed-batch adds nutrients during fermentation, and continuous culture maintains steady-state conditions. The aerated stirred tank bioreactor is the most widely used design for its efficiency and versatility across these operational strategies.
Q7: What components are essential for gas exchange and aeration in bioreactors?
A sparger plate introduces air or gas to facilitate aeration and oxygen transfer to the culture. An air exhaust releases gases produced during fermentation. The headspace above the liquid accommodates gas exchange and foam control, typically comprising about 25% of the bioreactor's total volume to ensure efficient oxygen availability.