title: Impact of abrupt temperature increase on the performance of an anaerobic hybrid bioreactor and its intrinsic microbial community.
abstract: This study aimed to analyse the effect of sudden temperature increases (in the range of 45-65 °C) on the performance and the microbial community structure of a hybrid anaerobic reactor. The reactor recovered with time after every temperature shock up to the operating temperature of 55 °C. At 55 °C, a 10 °C shock resulting in an operating temperature of 65 °C, deteriorated the reactor's performance. At this condition, both, the diversity and the relative abundance of methanogenic groups, especially of Methanosaetaceae, were significantly affected as observed by DGGE fingerprinting and quantitative PCR. In contrast, at lower temperatures (i.e., 45 and 55 °C), thermal shocks seemed to have less effect due to the presence and maintenance of thermophilic strains, which prevented system deterioration. At 65 °C, the absence of any acetoclastic methanogen is assumed to be the cause of system failure.
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: K
authors.initials: K
authors.lastname: Kundu
authors.affiliation: Leibniz-Institut für Agrartechnik Potsdam-Bornim e.V. (ATB), Abteilung Bioverfahrenstechnik, Max-Eyth-Allee 100, D-14469 Potsdam, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Bergmann
authors.affiliation: Leibniz-Institut für Agrartechnik Potsdam-Bornim e.V. (ATB), Abteilung Bioverfahrenstechnik, Max-Eyth-Allee 100, D-14469 Potsdam, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Klocke
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. Electronic address: shilpi@dbeb.iitd.ac.in.
authors.forename: S
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: T R
authors.initials: TR
authors.lastname: Sreekrishnan
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D016000:Cluster Analysis; D058645:Denaturing Gradient Gel Electrophoresis; D018628:Gene Dosage; D008697:Methane / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology; D013696:Temperature
chemical_list: D012336:RNA, Ribosomal, 16S; D012722:Sewage; D008697:Methane
keywords: Anaerobic digestion; Biomethanation; DGGE; Quantitative PCR; Temperature shock