An auxostat is a continuous culture device which, while in operation, uses feedback from a measurement taken on the growth chamber to control the media flow rate, maintaining the measurement at a constant. Auxo was the Greek goddess of spring growth, and as a prefix represents nutrients. However, the most typical auxostats are pH-auxostats , with feedback between the growth rate and a pH meter.
Other auxostats may measure oxygen tension, ethanol concentrations, and sugar concentrations 
- Larsson G, Enfors S O, (1990). "The pH-auxostat as a tool for studying microbial dynamics in continuous fermentation". Biotechnology and Bioengineering. 36 (3): 224–232. >
- Gostomski P, Muhlemann M, Lin YH, Mormino R, Bungay H (1994). "Auxostats for continuous culture research". Journal of Biotechnology. 37 (2): 167–177.