1,3-propanediol (1,3-PD) was biosynthesised with Clostridium butyricum DSM 10702 using crude glycerol as a substrate. The batch fermentation of crude glycerol (70g/L) without previous purification produced a significant concentration of 1,3-propanediol (35.9g/L, Y-1,Y-3-PD/S=0.51g 1,3-PD/g glycerol) at 37 degrees C and pH 6.5. The maximum tolerance of C. butyricum DSM 10702 to the inhibitory effect of the substrate was 70g/L. In fed-batch fermentation, the 1,3-PD concentration was similar: 36.1g/L. Pretreatment processes for biodiesel-based crude glycerol based on ion exchange resins (Lewatit S8528 and Lewatit GF series) were evaluated. For the two different fermentation modes studied (batch and fed-batch systems), the pretreatment slightly improved the results reached in fermentations carried out with untreated crude glycerol, especially 1,3-PD productivity which increased from 0.52g/(Lh) for crude glycerol to 0.99g/(Lh) for pretreated glycerol. In batch fermentation of glycerol pretreated with a Lewatit S8528, a concentration of 41.4g/L of 1,3-PD was reached, similar to that found in fed-batch fermentation.