After being isolated, studied and selected, the bacterial strain is stored at -80°C.

When a new production run starts up, the strain is then seeded in Petri dishes.

A first, then second, preculture is done by inoculating a series of progressively larger flasks containing a culture medium that has been specially designed to grow the required strain.

Fermenters – bioreactors with a capacity of 2 to 3,000 litres – are inoculated with the precultures.

As a rule, the culturing takes less than 24 hours. During this time, it is important that the temperature, acidity, aeration and stirring conditions are carefully controlled so as to produce the optimum bacterial concentration inside the reactor.

At the end of the fermentation stage, the biomass is recovered by centrifugation.

At this point it is a highly concentrated ‘bacterial paste’ that must be dried very carefully in order to keep the bacteria alive.

In most cases, the paste is dried by lyophilisation (freeze-drying).

This involves dehydrating the product by evaporating off the water that it contains.

This phase can take from one to three days and produces a dry cake.

A final physical treatment results in a bacterial powder known as the ‘pure culture’.

In most cases, the highly concentrated pure culture will then be diluted to yield the desired concentration in the final product.

Our engineers can develop a more complex formulation to meet special needs.

In such cases, the pure culture will be mixed with other active ingredients such as other pure bacterial cultures, prebiotic fibres, digestive enzymes, vitamins, minerals, plant extracts, etc.