Batch vs Continuous Culture

In bioreactors, microbes can be grown using two main culture methods - batch and continuous.

Batch culture is a closed system where microbes grow in a fixed volume of nutrient medium.

All the required nutrients are added at the beginning, and apart from gases, nothing is added or removed during the incubation.

The batch culture follows the typical growth curve consisting of the lag, exponential, stationary, and eventually the death phase.

Once nutrients are exhausted, microbial growth stops, and the final product is harvested.

On the other hand, a continuous culture, often performed in a Chemostat, is an open system. Fresh nutrient medium is continuously added, while an equal volume of culture is simultaneously removed.

This setup maintains a constant volume and steady state by replenishing nutrients and removing waste.

As a result, microbes remain in the exponential growth phase for a longer time, ensuring steady-state growth and consistent productivity.