Name: fed-batch feeding strategies
Uploaded: 2026-03-12T13:57:38.000Z
Duration: 1 min 23 s
Channel: JoVE

Fed-batch culture is a semi-closed system in which substrates are added during fermentation, but the products remain in the bioreactor until the end of the process.The process starts with a limited substrate amount to support cell growth and allow controlled feeding during fermentation.As fermentation progresses, additional substrates are introduced either continuously or intermittently.When a substrate is added at the same concentration as the initial culture, the culture volume increases. This is known as variable-volume fed-batch culture.On the other hand, in fixed-volume fed-batch culture, a highly concentrated substrate is used. This minimizes volume change and results in high cell density.Cyclic fed-batch culture involves repeated cycles of partial harvest of the culture medium.Fresh substrates are added after each harvest to replenish the nutrients and extend production by promoting cell growth.As the substrates are consumed, the microbial growth rate slows and approaches the stationary phase.At this point, another cycle is initiated, restarting the fermentation process within the same run.

fed-batch culture

Fed-Batch Culture

Fed-batch culture is a widely used bioprocessing strategy combining aspects of batch culture with controlled substrate feeding to optimize cell growth and product formation. In this semi-closed system, nutrients are strategically added during fermentation, while the accumulated products and biomass remain within the bioreactor until the end of the operation. This controlled addition of substrates allows for better management of growth kinetics, nutrient limitation, and metabolite accumulation.Two primary configurations of fed-batch culture are distinguished by how the substrate is introduced. In variable-volume fed-batch culture, substrates are added in concentrations equivalent to those in the initial culture medium. This results in a progressive increase in the culture volume over time. This method is beneficial for maintaining consistent nutrient concentrations and reducing the buildup of inhibitory byproducts.On the other hand, fixed-volume fed-batch culture involves the addition of highly concentrated substrates. Due to the limited volume increment, this approach maintains a nearly constant working volume while supporting extended growth phases. It is often favored in processes requiring tight control over culture parameters or downstream processing constraints that limit volume expansion.&#160;Cyclic fed-batch culture introduces an additional layer of complexity by incorporating periodic partial harvests of the culture medium. Fresh substrate is replenished after each harvest to sustain microbial activity and prolong the production phase. This approach enables the fermentation to approximate a quasi-steady state, where growth and production rates are stabilized over successive cycles. The cyclic strategy is particularly advantageous for long-duration processes or those involving slow-growing organisms, as it mitigates nutrient depletion and toxic metabolite accumulation.Overall, fed-batch systems enhance control over fermentation dynamics, making them indispensable in industrial biotechnology and pharmaceutical manufacturing.

Fed-batch culture is a widely used bioprocessing strategy combining aspects of batch culture with controlled substrate feeding to optimize cell growth and ...

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Microbiology

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Industrial Microbiology

KEY TERMS AND CONCEPTS

fed-batch feeding strategies

Fed-batch culture uses controlled feeding to guide cell growth and product formation in bioprocessing. It combines features of batch culture with nutrient additions during fermentation. In this semi-closed system, fresh substrate is added while the biomass and products stay in the bioreactor until the run ends.

This feeding control helps manage growth rate, nutrient limits, and the buildup of metabolites. By adjusting when and how substrate is added, the process can support longer production phases. It also helps reduce problems caused by nutrient depletion or inhibitory byproducts.

Variable-volume fed-batch culture adds substrate in concentrations similar to those in the starting medium. As feed is added, the culture volume slowly increases over time. This method can keep nutrient levels more consistent and limit byproduct buildup.

Fixed-volume fed-batch culture uses highly concentrated substrate. Because the added feed takes up little space, the working volume stays nearly constant. This setup is useful when tight control over culture conditions is needed or when downstream processing limits how much the volume can grow.

Cyclic fed-batch culture adds another step through periodic partial harvests. After each harvest, fresh substrate is added back to keep microbial activity going. Over repeated cycles, the system can move toward a quasi-steady state, where growth and production rates become more stable. This approach is especially helpful for long processes or slow-growing organisms, and it helps reduce nutrient depletion and toxic metabolite buildup. In industrial biotechnology and pharmaceutical manufacturing, fed-batch systems are valued because they give better control over fermentation dynamics.

Fed-Batch Feeding Strategies

bioreactor design and operational system

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bioreactor controls-i

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bioreactor controls-ii

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bioreactor controls-iii

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designing growth media for bioreactors

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Fed-batch culture uses controlled feeding to guide cell growth and product formation in bioprocessing. It combines features of batch culture with nutrient additions during fermentation. In this semi-closed system, fresh substrate is added while the biomass and products stay in the bioreactor until the run ends. This feeding control helps manage growth rate, nutrient limits, and the buildup of metabolites. By adjusting when and how substrate is added, the process can support longer production...

scale-up processes

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downstream processing

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production of pharmaceuticals

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biological treatment of effluent and waste water 

biological-treatment-of-effluent-and-waste-water

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key terms and concepts

Learn how fed-batch culture uses controlled nutrient feeding to manage growth, reduce byproducts, and support variable-volume, fixed-volume, and cyclic fermentation.

Fed-Batch Feeding Strategies | JoVE K12

JoVE Core Microbiology provides an engaging introduction to the microbial world and its influence on health, industry, and the environment. This comprehensive collection covers key concepts such as microbial structure, metabolism, genetics, and ecology. It introduces essential laboratory techniques and microscopy methods through visually engaging animations. Corresponding scientist-in-action videos bridge classroom concepts with real-world research and applications.

microbiology

Fed-Batch Feeding Strategies

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