title: Analysis of microbial community adaptation in mesophilic hydrogen fermentation from food waste by tagged 16S rRNA gene pyrosequencing.
abstract: Dark fermentation is an attractive process for generation of biohydrogen, which involves complex microbial processes on decomposition of organic wastes and subsequent conversion of metabolic intermediates to hydrogen. The microbes present in an upflow anaerobic sludge blanket (UASB) reactor for waste water treatment were tested for application in batch dark fermentation of food waste at varying ratios of feedstock to heat-treated microbial inoculum (F/M) of 1-8 (g TVS/g TVS). Biohydrogen yields between 0.39 and 2.68 mol H2/mol hexose were obtained, indicating that the yields were highly dependent on the starting F/M ratio. The highest H2 purity of 66% was obtained from the first 8 h of fermentation at the F/M ratio of 2, whereas the highest H2 production was obtained after 35 h of fermentation at the F/M ratio of 5. Tagged 16S rRNA gene pyrosequencing showed that the seed culture comprised largely of uncultured bacteria with various Proteobacteria, Bacteroidetes, and Firmicutes, while the starting food waste contained mainly lactic acid bacteria. Enrichment of Firmicutes, particularly Clostridia and lactic acid bacteria occurred within 8 h of the dark fermentation and the H2 producing microcosm at 35 h was dominated >80% by Clostridium spp. The major H2 producer was identified as a Clostridial strain related to Clostridium frigidicarnis. This work demonstrated the adaption of the microbial community during the dark fermentation of complex food waste and revealed the major roles of Clostridia in both substrate degradation and biohydrogen production.
authors.affiliation: Enzyme Technology Laboratory, Bioresources Technology Unit, National Center for Genetic Engineering and Biotechnology, Thailand Science Park, Khlong Luang, Pathum Thani 12120, Thailand.
authors.forename: Thanaporn
authors.initials: T
authors.lastname: Laothanachareon
authors.affiliation: The Joint Graduate School for Energy and Environment (JGSEE), King Mongkut's University of Technology Thonburi, Thungkru, Bangkok 10140, Thailand.
authors.forename: Suwimon
authors.initials: S
authors.lastname: Kanchanasuta
authors.affiliation: Enzyme Technology Laboratory, Bioresources Technology Unit, National Center for Genetic Engineering and Biotechnology, Thailand Science Park, Khlong Luang, Pathum Thani 12120, Thailand.
authors.forename: Wuttichai
authors.initials: W
authors.lastname: Mhuanthong
authors.affiliation: The Joint Graduate School for Energy and Environment (JGSEE), King Mongkut's University of Technology Thonburi, Thungkru, Bangkok 10140, Thailand; Department of Chemical Engineering, King Mongkut's University of Technology North Bangkok, Bangkok 10800, Thailand; The Research and Technology Center for Renewable Products and Energy, King Mongkut's University of Technology North Bangkok, Bangkok 10800, Thailand.
authors.forename: Chantaraporn
authors.initials: C
authors.lastname: Phalakornkule
authors.affiliation: The Joint Graduate School for Energy and Environment (JGSEE), King Mongkut's University of Technology Thonburi, Thungkru, Bangkok 10140, Thailand; The Research and Technology Center for Renewable Products and Energy, King Mongkut's University of Technology North Bangkok, Bangkok 10800, Thailand; Department of Agro-Industrial, Food, and Environmental Technology, Faculty of Applied Science, King Mongkut's University of Technology North Bangkok, Bangkok 10800, Thailand; The Biosensor and Bioelectronics Technology Centre, King Mongkut's University of Technology North Bangkok, Bangkok 10800, Thailand. Electronic address: npp@kmutnb.ac.th.
authors.forename: Nipon
authors.initials: N
authors.lastname: Pisutpaisal
authors.affiliation: Enzyme Technology Laboratory, Bioresources Technology Unit, National Center for Genetic Engineering and Biotechnology, Thailand Science Park, Khlong Luang, Pathum Thani 12120, Thailand. Electronic address: verawat@biotec.or.th.
authors.forename: Verawat
authors.initials: V
authors.lastname: Champreda
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D019149:Bioreactors; D004269:DNA, Bacterial / Q000235:genetics; D005285:Fermentation; D005511:Food Handling; D006859:Hydrogen / Q000378:metabolism*; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D006859:Hydrogen
keywords: 16S rRNA gene; Bacterial community; Dark fermentation; Food waste; Hydrogen; Pyrosequencing