Renewable feedstocks (e.g., crops, lignocellulosics, green biomass, residues) can be utilized directly, e.g., as energy carriers, as packaging materials, as fibers, for the production of coloring agents or as lubricants. However, they can also be converted biotechnol. by enzymes and microorganisms, giving us access to a multitude of new, biocompatible products and possible uses. Often the ecnomy of bioprocesses is still the problem because in the case of bulk products, the price is affected mainly by raw material costs. The production of environmental friendly, climatically sustainable basic chems. based on renewable raw materials can help to save limited fossil resources and to increase the economic potential of rural areas. The cultivation and utilization of renewable resources for the non-food application become an alternative source of revenue in agriculture and forestry. Even though the manifold potential is used only for a small part today, the production and processing of renewable resources will be a growing economic factor in future. The sugars after the pre-treatment of several agricultural and forestry feedstocks can be converted by lactic acid bacteria to produce lactic acid. Lactic acid, its salts and esters have a wide range of potential uses and are extensively used in diverse fields, e.g., bioplastics. The goal is to develop a fermentation process based on the substitution of expensive nutrients and supplements by cheaper materials from renewable resources due to their main proportion of the whole process costs. Besides the basic research projects respecting the screening and characterization of microorganisms, phenotypic optimization, down-stream processing of fermentation products, application and refining of lactic acid, economic assessment of bioconversion processes the scale-up to a tech. scale of several processing steps have to be developed for transferable solutions of bioconversion technologies of renewable materials. For that purpose a multifunctional pilot plant was planned and built at the site of ATB to investigate different raw materials and products. The construction of a pilot facility for the production of lactic acid from renewable resources consequently fills a gap in the various phases of bioprocess engineering from applied fundamental through application research to the launch of biotechnol. processes in practice. First results of lactic acid fermentation in a 450-L bioreactor will be presented. Depending on the further processing of the lactic acid the separation of impurities after fermentation is a major process cost too. Therefore an optimization is necessary to find a balance between the substitution of expensive nutrients and the limitation of interfering or undesirable components of natural raw materials resp. Exploitation of high quality L(+)- and D(-) lactic acid for the production of biopolymers is one of the recent applications. Conventional processes for down-streaming are based on precipitation steps that generate large amounts of chem. effluents. Consequently the environmental impact of traditional processes can be reduced by using alternative technologies, such as electrodialysis with monopolar and bipolar membranes.