Anaerobic Thermophilic Mixed Culture Fermentation Processes
Advantageous properties, such as higher hydrogen production, high substrate degradation rate, and efficient heat utilization for the treatment of hot wastewater, favor the thermophilic mixed culture fermentation (MCF) over mesophilic MCF. In this chapter, the typical metabolic reactions in thermophilic MCF are summarized in Sect. 2 according to the multistep process of hydrolysis/acidogenesis, acetogenesis/homoacetogenesis, and methanogenesis. The operational conditions, such as pH, H2 partial pressure, and reactor configuration, may change the microbial community or the metabolic pathway in thermophilic MCF and are reviewed in Sect. 3. Lastly, the metabolites both in the headspace and in liquid solutions are always a mixture in thermophilic MCF, which have to be concentrated and purified before utilization. There are several conventional technologies to separate the metabolites and recover energy, including biogas upgrading, two-stage fermentation, gas stripping, electrodialysis (ED), and microbial fuel cells. These typical technologies, along with other novel technologies, such as production of sole metabolite and medium-chain carboxylic acids production, are reviewed in Sect. 4. The energy cost of thermophilic biogas plants was estimated as just 10% of the energy produced, which implies that the extra energy cost for operating at a thermophilic temperature is marginal. Therefore, the coupling of the process and development of novel technologies are necessary in thermophilic MCF to promote its worldwide application.
KeywordsThermophilic mixed culture fermentation Metabolic pathway Operational factors Metabolite separation and purification Biorefinery
The authors would like to acknowledge the financial support from the National Natural Science Foundation of China (51408530, 50978244, and 51478447), Natural Science Foundation of Hebei Province (E2015203306), Foundation of Hebei Education Department (BJ2017014), and the Program for Changjiang Scholars and Innovative Research Team in University.
- Artzi L, Morag E, Barak Y, Lamed R, Bayer EA (2015) Clostridium clariflavum: key cellulosome players are revealed by proteomic analysis. MBio 6(3):e00411–15Google Scholar
- Lee HS, Krajmalinik-Brown R, Zhang HS, Rittmann BE (2009) An electron-flow model can predict complex redox reactions in mixed-culture fermentative BioH(2): microbial ecology evidence. Biotechnol Bioeng 104(4):687–697Google Scholar
- Lengeler JW, Drews G, Schlegel HG (1999) Biology of the prokaryotes. Georg Thieme, StuttgartGoogle Scholar
- Madigan M, Martinko J, Bender K, Buckley D, Stahl D (2002) The Brock biology of microorganisms (Global ed). Pearson Education Limited, HarlowGoogle Scholar
- Moon HG, Jang YS, Cho C, Lee J, Binkley R, Lee SY (2016) One hundred years of clostridial butanol fermentation. FEMS Microbiol Lett 363(3):fnw001Google Scholar
- Perry RH, Green DW (2008) Perry’s chemical engineers’ handbook. McGraw-Hill, New YorkGoogle Scholar
- Petersson A, Wellinger A (2009) Biogas upgrading technologies–developments and innovations, vol 37. IEA-Task, p 20Google Scholar
- Poehlein A, Schmidt S, Kaster A-K, Goenrich M, Vollmers J, Thürmer A, Bertsch J, Schuchmann K, Voigt B, Hecker M, Daniel R, Thauer RK, Gottschalk G, Müller V (2012) An ancient pathway combining carbon dioxide fixation with the generation and utilization of a sodium ion gradient for ATP synthesis. PLoS One 7(3):e33439CrossRefGoogle Scholar
- Speight JG (2005) Lange’s handbook of chemistry. McGraw-Hill, New YorkGoogle Scholar
- Tapia-Venegas E, Ramirez-Morales J, Silva-Illanes F, Toledo-Alarcón J, Paillet F, Escudie R, Lay C-H, Chu C-Y, Leu H-J, Marone A, Lin C-Y, Kim D-H, Trably E, Ruiz-Filippi G (2015) Biohydrogen production by dark fermentation: scaling-up and technologies integration for a sustainable system. Rev Environ Sci Biotechnol 14(4):761–785CrossRefGoogle Scholar
- Thauer RK, Jungermann K, Decker K (1977) Energy conservation in chemotrophic anaerobic bacteria. Bacteriol Rev 41(1):100–180Google Scholar
- Yentekakis IV, Goula G (2017) Biogas management: advanced utilization for production of renewable energy and added-value chemicals. Front Environ Sci 5:7Google Scholar