Vacuum promotes metabolic shifts and increases biogenic hydrogen production in dark fermentation systems
- 169 Downloads
The successful operation of any type of hydrogen-producing bioreactor depends on the performance of the microorganisms present in the system. Both substrate and partial gas pressures are crucial factors affecting dark fermentation metabolic pathways. The main objective of this study was to evaluate the impact of both factors on hydrogen production using anaerobic granular sludge as inoculum and, secondly, to study the metabolic shifts of an anaerobic community subjected to low partial gas pressures. With this goal in mind, seven different wastewater (four synthetic media, two industrial wastewater, and one domestic effluent) and the effect of applying vacuum on the systems were analyzed. The application of vacuum promoted an increase in the diversity of hydrogenproducing bacteria, such as Clostridium, and promoted the dominance of acetoclastic- over hydrogenotrophic methanogens. The application of different media promoted a wide variety of metabolic pathways. Nevertheless, reduction of the hydrogen partial pressure by application of vacuum lead to further oxidation of reaction intermediates irrespective of the medium used, which resulted in higher hydrogen and methane production, and improved the COD removal. Interestingly, vacuum greatly promoted biogenic hydrogen production from a real wastewater, which opens possibilities for future application of dark fermentation systems to enhance biohydrogen yields.
Keywordsdark fermentation biohydrogen wastewaters vacuum
Unable to display preview. Download preview PDF.
- 1.Stronach S M, Rudd T, Lester J N. Anaerobic Digestion Processes in Industrial Wastewater Treatment. Biotechnology Monographs. Berlin: Germany Springer-Verlag, 1986Google Scholar
- 16.Standard Methods for the Examination of Water and Wastewater. Washington DC: American Public Health Association/American Water Works Association/Water Environment Federation, 1998Google Scholar
- 20.Toh H, Sharma V K, Oshima K, Kondo S, Hattori M, Ward F B, Free A, Taylor T D. Complete genome sequences of Arcobacter butzleri ED-1 and Arcobacter sp. strain L, both isolated from a microbial fuel cell. Journal of Bacteriology, 2011, 193(22): 6411–6412Google Scholar
- 25.Jun Y S, Yu S H, Ryu K G, Lee T J. Kinetic study of pH effects on biological hydrogen production by a mixed culture. Journal of Microbiology and Biotechnology, 2008, 18(6): 1130–1135Google Scholar
- 33.Speece R E. Anaerobic Biotechnology (for Industrial wastewater). Nashville, Tennessee: Archae Press, 1996Google Scholar