Enzyme reactors and fermenters

Processes for the preparation of several consumer food products include at least one step involving micro-organisms or enzymes:

• when this stage involves micro-organisms that develop by consuming part of a reagent called substrate and transforming the other part into various products, the reactor used is a fermenter;

• if this stage is a biochemical reaction catalyzed by enzymes transforming a substrate into a product, it is carried out in an enzymatic reactor.

A distinction is commonly made between fermenters and enzymatic reactors, since the former involve living matter and often have to operate under sterile conditions.

The construction technologies for these two types of reactor are therefore different: fermenters require the use of materials resistant to heat sterilization, and must be absolutely leak-proof.

This technological distinction masks, however, the similarity of the phenomena involved in enzymatic reactors and fermenters.

The aim of this article is to present, from a general point of view, the different types of fermenters and enzymatic reactors, their design principles and their modes of use.