Chemostaten

Chemostaten is a term used to refer to chemostats, a class of continuous culture bioreactors used to grow microorganisms under steady-state conditions. In Dutch-language literature, the plural form chemostaten is common, while English texts typically use chemostats.

The central principle of a chemostaten system is the regulation of growth by a limiting nutrient. Fresh medium containing a restricted amount of a key substrate is continuously fed into the culture, while culture broth is simultaneously removed at the same rate. When the rate of inflow (the dilution rate) matches the organism’s growth rate, the culture reaches a steady state characterized by constant biomass, substrate, and product concentrations. This allows researchers to study physiology and metabolism under defined, reproducible conditions.

Designs of chemostats vary, but most include a culture vessel, a feed line with a pump, an effluent line, and control systems to adjust the feed rate. Sensors or indirect measurements (such as optical density or substrate concentration) inform feedback loops that maintain the desired dilution rate and nutrient levels. Chemostats may be run as single units or arranged in arrays to investigate interactions among species or to optimize production processes.

Applications span basic microbiology, metabolic engineering, and industrial biotechnology. They are used to determine growth kinetics, study nutrient limitation effects, monitor product formation, and optimize the production of compounds like enzymes, antibiotics, or biofuels. Limitations include potential adaptation to steady-state conditions and differences from batch or fed-batch behavior, which must be considered when translating results to other systems.