Enhanced fermentative production of 1,3 propanediol by employing ethanol industry wastewater

The co-fermentation of glycerol (Gly) with sugarcane vinasse (SV) can increase yields of 1,3-propanediol while reducing its biosynthesis costs. Thus, this study aimed to evaluate the effect of temperature in (hyper) thermophilic range (55 °C, 60 °C, and 65 °C) on continuous 1,3-propanediol production by mixed culture in fluidized bed reactors fed with different proportions of these co-substrates. 1,3-propanediol and H2 were both detected with 25%Gly: 75%SV at 55 °C and 60 °C (0.67–0.65 mol 1,3-PD mol−1Gly and 0.74–0.70 mmol H2 g−1COD, respectively) and with 75%Gly:25%SV at 55 °C (0.49 mol 1,3-PD mol−1Gly and 0.35 mmol H2 g−1COD) due to simultaneous acetic and butyric acids production. H2 was not detected at 65 °C in any of the reactors. Conversely, high temperatures with 50%Gly:50%SV favored 1,3-propanediol production (0.89 mol 1,3-PD mol−1Gly). Therefore, SV is a suitable co-substrate to increase the NADRed: NADOx ratio and favor the reductive branch of the Gly metabolization.