Bioreactor is used to investigate fermentation and similar biological processes. The medium is initially prepared, sterilized, and then inoculated. Growth takes place in batch mode over time. In case of aerobic growth, aeration takes place through sparger with supplied pressurized air and distributed by means of a set of impellers. Various ports are provided for sampling, acid addition, base addition, air vent, condenser connection, temperature sensor, pH sensor, DO sensor, and other required measurements. The unit is equipped with jacket for heating/cooling of the medium. Three peristaltic pumps for feed, acid, and base supply are provided and flow rates are controlled by rotameters. All pumps, rotameters, and analyzers are mounted on a control panel. This unit is a mechanical agitated type and manufactured in 2, 3, 5, 10, and 20 L capacities.