Simultaneous Hydrogen and Ethanol Production from Crude Glycerol by a Microbial Consortium Using Fed-Batch Fermentation

Simultaneous bioproduction of hydrogen and ethanol from cheaper waste feedstock has the potential for development a more cost-effective biofuel generation process. Crude glycerol (CG), by-product biodiesel industry, is renewable resource, abundant, sold at low prices available worldwide. However, main CG limitations in fermentation processes are mainly related to presence impurities lack nitrogen sources, both acting on microbial activity. In this study, process with was improved using highly specific consortium called GlyCeroL (GCL). The developed fed-batch mode not diluted substrate carried out under non-sterile conditions increasing amounts (from 20 80 gL−1 glycerol). results showed higher H2 6 8 LL−1) EtOH 13 gL−1) production by concentration 40 gL−1. On other hand, decrease degradation efficiency 75 56%) observed. Then, sparging strategy applied. Using gL−1, improvement achieved, leading increased (10 but that (20 gL−1). A further increase 60 produced slight increment (21 (11 sharp (41%). Acetate, as impurity CG, an additional carbon source GCL microorganisms contributing lactic acid restore redox balance. Denaturing Gradient Gel Electrophoresis (DGGE) fingerprint end all fermentations supported robustness functional units their adaptability conditions.