Bioremediation of Crude Glycerol by a Sustainable Organic–Microbe Hybrid System

Klebsiella pneumoniae with crude glycerol-utilizing and hydrogen (H(2))-producing abilities was successfully isolated from return activated sludge from Shatin Sewage Treatment Works. The H(2) production strategy used in this study was optimized with crude glycerol concentrations, and 1,020 μmol of H(2) was generated in 3 h. An organic–microbe hybrid system was constructed with metal-free hydrothermal carbonation carbon (HTCC) microspheres to enhance the H(2) production under visible light (VL) irradiation. Under optimized VL intensity and HTCC concentration, an elevation of 35.3% in H(2) production can be obtained. Electron scavenger study revealed that the photogenerated electrons (e(–)) from HTCC contributed to the additional H(2) production. The variation in intercellular intermediates, enzymatic activity, and reducing equivalents also suggested that the photogenerated e(–) interacted with K. pneumoniae cells to direct the metabolic flux toward H(2) production. This study demonstrated the feasibility of using an organic–microbe hybrid system as a waste-to-energy technology.