Fermenters
There are many types of fermenters. The one shown in Appendix 2 is an aerated batch type fermenter. Its features include:
Sparger to supply air and oxygen
Motor and impeller to provide mixing.
Sterile ports for inoculating and taking samples
Cooling water jacket to remove heat.
pH control
Port to harvest the medium at the conclusion of fermentation
Steam inlet to sterilize the fermenter.
Scale-Up from Laboratory to Commercial Fermenter
An important aspect of industrial microbiology is the transfer of a
process from small-scale laboratory equipment to large-scale commercial equipment, a process called scale-up. An understanding of scale-up is important because industrial processes rarely behave
the same way in large-scale fermentors as in small-scale laboratory equipment.
Many scale-up challenges arise from
problems with aeration and mixing. Oxygen transfer is much more difficult to achieve in large fermentors than in small fermentors
because the rich culture media used in industrial fermentations support high cell densities, and this leads to high oxygen demand. If oxygen levels become limiting, even for a short period, the culture may reduce—or even shut down—product formation.
In the development of an industrial process, everything begins in the laboratory flask. From here, a promising process is scaledup to the laboratory fermentor, a small vessel, generally made of glass and 1 to 10 liters in size. In the laboratory fermentor it is possible to test variations in culture media, temperature, pH, and other parameters, quickly and inexpensively.