... (Optional automatic sterilization procedures)Control system: Siemens PLC, industrial LCD touch computer control, parameters can be set to ... 12.00±0.05pH, autocontrol by adding acid and base, pH sensor (Mettler, Switzerland) and shielding lead (Mettler, Switzerland). fermenter ... and control 0-150±3% displaying precision 0.1%, sensor (Mettler, Switzerland) and shielding lead(Mettler, Switzerland) Feed ...