title: Temperature-dependent transformation of biogas-producing microbial communities points to the increased importance of hydrogenotrophic methanogenesis under thermophilic operation.
abstract: Stability of biogas production is highly dependent on the microbial community composition of the bioreactors. This composition is basically determined by the nature of biomass substrate and the physical-chemical parameters of the anaerobic digestion. Operational temperature is a major factor in the determination of the anaerobic degradation process. Next-generation sequencing (NGS)-based metagenomic approach was used to monitor the organization and operation of the microbial community throughout an experiment where mesophilic reactors (37°C) were gradually switched to thermophilic (55°C) operation. Temperature adaptation resulted in a clearly thermophilic community having a generally decreased complexity compared to the mesophilic system. A temporary destabilization of the system was observed, indicating a lag phase in the community development in response to temperature stress. Increased role of hydrogenotrophic methanogens under thermophilic conditions was shown, as well as considerably elevated levels of Fe-hydrogenases and hydrogen producer bacteria were observed in the thermophilic system.
authors.affiliation: Seqomics Biotechnology Ltd., Vállalkozók útja 7, H-6782 Mórahalom, Hungary. Electronic address: bernadett.pap@gmail.com.
authors.forename: Bernadett
authors.initials: B
authors.lastname: Pap
authors.affiliation: Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary. Electronic address: gyorkei.adam@gmail.com.
authors.forename: Ádám
authors.initials: Á
authors.lastname: Györkei
authors.affiliation: Politehnica University of Timisoara, Hydrotechnical Engineering Dept., George Enescu str. 1/A, 300022 Timisoara, Romania. Electronic address: boboescu.iulian@yahoo.com.
authors.forename: Iulian Zoltan
authors.initials: IZ
authors.lastname: Boboescu
authors.affiliation: Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary. Electronic address: nagyildi@baygen.hu.
authors.forename: Ildikó K
authors.initials: IK
authors.lastname: Nagy
authors.affiliation: Szent István University, Faculty of Economics, Agricultural and Health Studies, Szabadság út 1-3, H-5540 Szarvas, Hungary. Electronic address: biro.tibor@gk.szie.hu.
authors.forename: Tibor
authors.initials: T
authors.lastname: Bíró
authors.affiliation: Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary. Electronic address: eva.kondorosi@gmail.com.
authors.forename: Éva
authors.initials: É
authors.lastname: Kondorosi
authors.affiliation: Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary; Politehnica University of Timisoara, Hydrotechnical Engineering Dept., George Enescu str. 1/A, 300022 Timisoara, Romania. Electronic address: marotig@baygen.hu.
authors.forename: Gergely
authors.initials: G
authors.lastname: Maróti
mesh_terms: D000222:Adaptation, Physiological; D001419:Bacteria / Q000378:metabolism*; D056804:Biofuels / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology; D005232:Fatty Acids, Volatile / Q000032:analysis; D006859:Hydrogen / Q000378:metabolism*; D006864:Hydrogenase / Q000378:metabolism; D008697:Methane / Q000096:biosynthesis*; D010802:Phylogeny; D013312:Stress, Physiological; D013696:Temperature
chemical_list: D056804:Biofuels; D005232:Fatty Acids, Volatile; D006859:Hydrogen; D006864:Hydrogenase; D008697:Methane
keywords: Anaerobic digestion; Hydrogenase; Hydrogenotrophic methanogenesis; Metagenomics; Thermophilic microbial community