[Industrial exploitation of renewable resources: from ethanol production to bioproducts development].

Abstract

Plants, which are one of major groups of life forms, are constituted of an amazing number of molecules such as sugars, proteins, phenolic compounds etc. These molecules display multiple and complementary properties involved in various compartments of plants (structure, storage, biological activity etc.). The first uses of plants in industry were for food and feed, paper manufacturing or combustion. In the coming decades, these renewable biological materials will be the basis of a new concept: the "biorefiner" i.e. the chemical conversion of the whole plant to various products and uses. This concept, born in the 90ies, is analogous to today's petroleum refinery, which produces multiple fuels and derivative products from petroleum. Agriculture generates lots of co-products which were most often wasted. The rational use of these wasted products, which can be considered as valuable renewable materials, is now economically interesting and will contribute to the reduction of greenhouse has emissions by partially substituting for fossil fuels. Such substructures from biological waste products and transforming them into biofuels and new industrial products named "bioproducts". These compounds, such as bioplastics or biosurfactants, can replace equivalent petroleum derivatives. Towards that goal, lots of filamentous fungi, growing on a broad range of vegetable species, are able to produce enzymes adapted to the modification of these type of substrates. The best example, at least the more industrially developed to date, is the second generation biofuel technology using cellulose as a raw material. The process includes an enzymatic hydrolysis step which requires cellulases secreted from Trichoderma fungal species. This industrial development of a renewable energy will contribute to the diversification of energy sources used to transport and to the development of green chemistry which will partially substitute petrochemicals.