title: Achieving ethanol-type fermentation for hydrogen production in a granular sludge system by aeration.
abstract: To investigate the effects of aeration on hydrogen-producing granular system, experiments were performed in two laboratory-scale anaerobic internal circulation hydrogen production (AICHP) reactors. The preliminary experiment of Reactor 1 showed that direct aeration was beneficial to enhancing hydrogen production. After the direct aeration was implied in Reactor 2, hydrogen production rate (HPR) and hydrogen content were increased by 100% and 60%, respectively. In addition, mixed-acid fermentation was transformed into typical ethanol-type fermentation (ETF). Illumina MiSeq sequencing shows that the direct aeration did not change the species of hydrogen-producing bacteria but altered their abundance. Hydrogen-producing bacteria and ethanol-type fermentative bacteria were increased by 24.5% and 146.3%, respectively. Ethanoligenens sp. sharply increased by 162.2% and turned into predominant bacteria in the system. These findings indicated that appropriate direct aeration might be a novel and promising way to obtain ETF and enhance hydrogen production in practical use.
authors.affiliation: College of Architecture and Environment, Sichuan University, Chengdu 610065, China.
authors.forename: Song
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Architecture and Environment, Sichuan University, Chengdu 610065, China.
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.affiliation: College of Architecture and Environment, Sichuan University, Chengdu 610065, China. Electronic address: cylm@163.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.affiliation: College of Architecture and Environment, Sichuan University, Chengdu 610065, China.
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Pan
mesh_terms: D001419:Bacteria / Q000145:classification / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D000068016:Eubacteriales / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006859:Hydrogen / Q000378:metabolism*; D058889:Molecular Typing; D012722:Sewage / Q000382:microbiology*
chemical_list: D012722:Sewage; D000431:Ethanol; D006859:Hydrogen
keywords: Aeration; Dark fermentative hydrogen production; Ethanol-type fermentation; Ethanoligenens sp.; Hydrogen-producing bacteria