Turbidostat
Encyclopedia
A turbidostat is a continuous culture device, similar to a chemostat
or an auxostat
, which has feedback between the turbidity of the culture vessel and the dilution rate. The theoretical relationship between growth in a chemostat
and growth in a turbidostat is somewhat complex, in part because it is similar. A chemostat
technically has a fixed volume and flow rate - thus a fixed dilution rate. When the cells are uniform and at equilibrium, operation of a chemostat and turbidostat should be identical. It is only when classical chemostat assumptions are violated (for instance, out of equilibrium; or the cells are mutating) that a turbidostat is functionally different. One case may be while cells are growing at their maximum growth rate, in which case it is difficult to set a chemostat to the appropriate constant dilution rate
.
While most turbidostats use a spectrophotometer/turbidometer to measure the optical density for control purposes, there exist other options, such as dielectric permittivity .
Chemostat
A chemostat is a bioreactor to which fresh medium is continuously added, while culture liquid is continuously removed to keep the culture volume constant...
or an auxostat
Auxostat
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...
, which has feedback between the turbidity of the culture vessel and the dilution rate. The theoretical relationship between growth in a chemostat
Chemostat
A chemostat is a bioreactor to which fresh medium is continuously added, while culture liquid is continuously removed to keep the culture volume constant...
and growth in a turbidostat is somewhat complex, in part because it is similar. A chemostat
Chemostat
A chemostat is a bioreactor to which fresh medium is continuously added, while culture liquid is continuously removed to keep the culture volume constant...
technically has a fixed volume and flow rate - thus a fixed dilution rate. When the cells are uniform and at equilibrium, operation of a chemostat and turbidostat should be identical. It is only when classical chemostat assumptions are violated (for instance, out of equilibrium; or the cells are mutating) that a turbidostat is functionally different. One case may be while cells are growing at their maximum growth rate, in which case it is difficult to set a chemostat to the appropriate constant dilution rate
.
While most turbidostats use a spectrophotometer/turbidometer to measure the optical density for control purposes, there exist other options, such as dielectric permittivity .