Chemostat bioreactors for continuous cultures
Continuous culturing in a chemostat bioreactor involves having an ongoing feed of fresh nutrient medium, while discharging an equal mass of consumed medium, including biomass. The goal of a chemostat process is to keep all parameters, including culture growth and death rates, constant by controlling the addition of nutrient medium. Once these reach steady state, variables such as the organism’s metabolism can be analyzed as a function of changing parameters. The process also opens up the possibility of increased productivity, in that the growth rate is kept at the optimum level for the product formation rate.
Achieving steady-state conditions through continuous monitoringMaintaining steady-state conditions for cells or microorganisms over a relatively long period of time requires detailed insight into the culturing process. A large number of available sensors, such as waste gas analysis, live cell density and biomass sensors, opens up the possibility of continuous monitoring for critical parameters. Bioprocess software allows researchers to use these data for calculating additional parameters such as the growth rate (µ), so that they can perfectly adapt the nutrient feed to the chemostat bioprocess. Altering the rate at which fresh medium is added in chemostat processes (dilution rate D) makes it possible to control the growth rate, thus keeping this parameter constant within a range that maximizes the biomass product formation rate.
Precise nutrient feed and dilution rate controlThe pump for the addition of substrate can be controlled either directly on the bioreactor or using a specific bioprocess software. An example of a major advantage of bioprocess software is that soft sensors can be used for setting the dilution rate and, in so doing, prevent cell washout. If the dilution rate is greater than the maximum growth rate under the selected conditions, the biomass will be flushed out of the chemostat bioreactor.
Connecting additional pumps and scalesBecause fresh medium is constantly fed into continuous bioprocesses and consumed medium is constantly pumped out, the pumps typically integrated in bioreactors are often not up to the task. Additional, external pumps can be connected if a bioreactor has additional analog input and output ports. Connecting a scale also allows gravimetric feeding for a precise addition of nutrients over long periods of time. In order to be certain that the external pump and/or scale can communicate with the bioreactor, it helps to order preconfigured equipment directly from the bioreactor manufacturer.
Switching between batch and continuous operation easilyThe advantage of being able to freely select the operating mode for the bioreactor's integrated pumps is that the pumps can then be reconfigured quickly and easily. This would allow operators, for example, to take an antifoam pump that they no longer need and convert it to an analog feed pump just by pressing a button. In other words, a batch process can be converted to a chemostat process without having to procure additional equipment or use up additional lab space.
Your chemostat bioreactor
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Our bioreactors for continuous culture
The award-winning, all-in-one bioreactor
Total volume up to 6 L
Additional external pump (optional)
External balance may be connected
Preconfigured and ready-to-use
eve® – the bioprocess platform software
Workflow-oriented planning tools and comprehensive options for bioprocess control and monitoring
Monitor and control bioprocess parameters from any location
Powerful feeding strategies
Soft sensors for comprehensive process data analysis
Validation according to FDA 21 CFR part 11