title: Description ofProteiniphilum saccharofermentanssp. nov.,Petrimonas mucosasp. nov. andFermentimonas caenicolagen. nov., sp. nov., isolated from mesophilic laboratory-scale biogas reactors, and emended description of the genusProteiniphilum.
abstract: Three novel, facultatively anaerobic bacteria of the familyPorphyromonadaceae(phylumBacteroidetes) were isolated from mesophilic laboratory-scale biogas reactors. The strains were Gram-negative rods. Optimal growth occurred between 35 and 45 °C and at pH 7.1-7.8. The main fermentation products were acetic and propionic acids. The predominant fatty acid in all strains was anteiso-C15 : 0, and the only respiratory quinone detected was menaquinone MK-8. 16S rRNA gene sequence comparison indicated that strains M3/6Tand ING2-E5BTwere most closely related to the type strain ofProteiniphilum acetatigenes, with sequence similarities of 97.3 and 94.5 %. Strain ING2-E5ATshowed the closest affiliation to the type strain ofPetrimonas sulfuriphila, with 97 % sequence identity. DNA-DNA hybridization of strain M3/6Tand ING2-E5ATwith the most closely related type strains showed 43.3-45.6 and 23.8-25.7 % relatedness, respectively, which supports the conclusion that both isolates represent novel species. Phylogenetic analysis and comparison of cellular fatty acid patterns indicated that strain ING2-E5BTcannot be classified as a member of any previously described genus. Therefore, because of the physiological, genotypic and chemotaxonomic differences, it is proposed to designate novel species within the generaProteiniphilumandPetrimonas,Proteiniphilum saccharofermentanssp. nov. (type strain M3/6T= DSM 28694T= CECT 8610T= LMG 28299T) andPetrimonas mucosasp. nov. (type strain ING2-E5AT= DSM 28695T= CECT 8611T), and a novel species of a new genus,Fermentimonas caenicolagen. nov., sp. nov. (type strain ofFermentimonas caenicolais ING2-E5BT= DSM 28696T= CECT 8609T= LMG 28429T). In addition, an emended description of the genusProteiniphilumis provided.
authors.affiliation: Department of Bioengineering, Leibniz Institute for Agricultural Engineering Potsdam-Bornim, D-14469, Potsdam, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Hahnke
authors.affiliation: Department of Bioengineering, Leibniz Institute for Agricultural Engineering Potsdam-Bornim, D-14469, Potsdam, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Langer
authors.affiliation: Institute for Microbiology, Technische Universität München, D-85350 Freising-Weihenstephan, Germany.
authors.forename: Daniela E
authors.initials: DE
authors.lastname: Koeck
authors.affiliation: Department of Bioengineering, Leibniz Institute for Agricultural Engineering Potsdam-Bornim, D-14469, Potsdam, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Klocke