In this study, the isolated strain, Citrobacter freunfiii AD970, was genetically modified to improve production of 1,3-propanediol (1,3-PD). The strain was modified through overexpression of 1,3-PD oxidoreductase (PDOR from Shimwellia blattae). Catalyzing the final step of glycerol-to-1,3-PD conversion. The aim of such approach was to decrease accumulation of toxic 3-hydroxypropionaldehyde (3-HPA) and to increase 1,3-PD synthesis.