Ethanolic fermentation as a tool for high added value products purification from biomass

The biorefinery concept implies the development of processes in order to valorise the whole part of a crop. In this concept, white biotechnologies are usually considered for the production of new compounds or compounds actually derived from the oil industry. For example, interest in ethanolic fermentation is growing nowadays, mainly for its energetic applications, starting from starch or saccharose. Biorefinery integrating lignocellulosic materials are under development. Whatever the initial substrate may be, wet technologies would produce sugars and other soluble materials from the biomass. Different results could be expected:most of the hydrolysates molecules are used by the microorganisms;some molecules could be inhibitors for the fermentation;some molecules are "indifferent ones" and could be concentrated by the fermentation proccess followed by distillation. In the latest case, these molecules are concentrated in the residual medium and could be more easily recuperated. An example of this exists in the production of ethanol from beet. The different juices (diffusion, clarified, ...) contain molecules such as raffinose, glutamine, betaine, saponins or pectic materials. Some products are used by the yeasts and other are concentrated. Our purpose is to summary the results obtained, allowing the development of the concept in other biorefinery applications.