Popis: |
The present paper reports the results of Citrobacter freundii, strain DSM 15979, that was tested for its ability to produce value added chemicals from biodiesel derived glycerol in a mesophilic fluidized bed biofilm reactor operating under continuous conditions at a specified hydraulic retention time (HRT) at 30°C. Elevating feed concentrations (10 to 144 g/L) were tested in order to understand their effects on simultaneous production of value added products with immobilized whole cells. Gin was found to be a significant independent variable for the productions of 1,3-PDO, 2,3-BD, ethanol, acetic, succinic and lactic acids under different organic loading rates (OLR). The major metabolite in the metabolic pathway was found to be 1,3-PDO followed by 2,3-BD reaching the maximum values as 26.1 and 18.8 g/L under the conditions of 92 g/L crude glycerol and 8 h, which is represents an OLR of 11.5 g/L.h, suggesting the formation of biofilms favor the utilization of high substrate concentration to enhance the mixed fermentation. |