title: A modeling approach to direct interspecies electron transfer process in anaerobic transformation of ethanol to methane.
abstract: Recent studies have shown that direct interspecies electron transfer (DIET) plays an important part in contributing to methane production from anaerobic digestion. However, so far anaerobic digestion models that have been proposed only consider two pathways for methane production, namely, acetoclastic methanogenesis and hydrogenotrophic methanogenesis, via indirect interspecies hydrogen transfer, which lacks an effective way for incorporating DIET into this paradigm. In this work, a new mathematical model is specifically developed to describe DIET process in anaerobic digestion through introducing extracellular electron transfer as a new pathway for methane production, taking anaerobic transformation of ethanol to methane as an example. The developed model was able to successfully predict experimental data on methane dynamics under different experimental conditions, supporting the validity of the developed model. Modeling predictions clearly demonstrated that DIET plays an important role in contributing to overall methane production (up to 33 %) and conductive material (i.e., carbon cloth) addition would significantly promote DIET through increasing ethanol conversion rate and methane production rate. The model developed in this work will potentially enhance our current understanding on syntrophic metabolism via DIET.
authors.affiliation: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia.
authors.forename: Yiwen
authors.identifier: http://orcid.org/0000-0001-6677-7961
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
authors.forename: Yaobin
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia. ngohuuhao121@gmail.com.
authors.forename: Huu Hao
authors.initials: HH
authors.lastname: Ngo
authors.affiliation: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia.
authors.forename: Wenshan
authors.initials: W
authors.lastname: Guo
authors.affiliation: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia.
authors.forename: Junliang
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, Ghent, 9000, Belgium.
authors.forename: Lai
authors.initials: L
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China. bjni@tongji.edu.cn.
authors.forename: Bing-Jie
authors.initials: BJ
authors.lastname: Ni
mesh_terms: D000693:Anaerobiosis; D002244:Carbon / Q000737:chemistry; D004579:Electron Transport; D000431:Ethanol / Q000032:analysis* / Q000378:metabolism; D045302:Geobacter / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism; D008697:Methane / Q000032:analysis* / Q000378:metabolism; D017020:Methanosarcina / Q000378:metabolism*; D008962:Models, Theoretical; D013045:Species Specificity
chemical_list: D000431:Ethanol; D002244:Carbon; D006859:Hydrogen; D008697:Methane
keywords: Anaerobic digestion; Direct interspecies electron transfer (DIET); Ethanol; Mathematical model; Methane production; Syntrophy