Turbidostat

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.^[1][2] 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. And turbidostat adjusts the flow rate to make the turbidity constant thus the dilution rate also changes with change in turbidity 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 .^[3]

While most turbidostats use a spectrophotometer/turbidometer to measure the optical density for control purposes, there exist other options, such as dielectric permittivity.^[4]

References