The possibility of applying membrane distillation to support the fermentation process was investigated. The capillary polypropylene membranes were assembled in the membrane modules. The studies were carried out using the standard solutions containing the compounds frequently occurring in the broths such as ethanol, citric, acetic and lactic acids, glycerol and 1,3-propanediol. The performance of membrane bioreactor, in which glycerol was fermented by the use of Citrobacter freundii bacteria was also examined. The separation of particular components of broths was investigated in a long-term application of membrane distillation and a good resistance to wetting of the used polypropylene membrane was demonstrated during the two year period.