title: Dechloromonas denitrificans sp. nov., Flavobacterium denitrificans sp. nov., Paenibacillus anaericanus sp. nov. and Paenibacillus terrae strain MH72, N2O-producing bacteria isolated from the gut of the earthworm Aporrectodea caliginosa.
abstract: Earthworms emit nitrous oxide (N(2)O) via the activity of bacteria in their gut. Four N(2)O-producing facultative aerobes, ED1(T), ED5(T), MH21(T) and MH72, were isolated from the gut of the earthworm Aporrectodea caliginosa. The isolates produced N(2)O under conditions that simulated the microenvironment of the earthworm gut. ED1(T) and ED5(T) were Gram-negative, motile rods that carried out complete denitrification (i.e. the reduction of nitrate to N(2)) and contained membranous c-type cytochromes. ED1(T) grew optimally at 30 degrees C and pH 7. ED1(T) oxidized organic acids and reduced (per)chlorate, sulfate, nitrate and nitrite. The closest phylogenetic relative of ED1(T) was Dechloromonas agitata. ED5(T) grew optimally at 25 degrees C and pH 7. ED5(T) grew mainly on sugars, and nitrate and nitrite were used as alternative electron acceptors. The closest phylogenetic relatives of ED5(T) were Flavobacterium johnsoniae and Flavobacterium flevense. MH21(T) and MH72 were motile, spore-forming, rod-shaped bacteria with a three-layered cell wall. Sugars supported the growth of MH21(T) and MH72. Cells of MH21(T) grew in chains, were linked by connecting filaments and contained membranous b-type cytochromes. MH21(T) grew optimally at 30-35 degrees C and pH 7.7, grew by fermentation and reduced low amounts of nitrite to N(2)O. The closest phylogenetic relatives of MH21(T) were Paenibacillus borealis and Paenibacillus chibensis. Based on morphological, physiological and phylogenetic characteristics, ED1(T) (= DSM 15892(T) = ATCC BAA-841(T)), ED5(T) (= DSM 15936(T) = ATCC BAA-842(T)) and MH21(T) (=DSM 15890(T) = ATCC BAA-844(T)) are proposed as type strains of the novel species Dechloromonas denitrificans sp. nov., Flavobacterium denitrificans sp. nov. and Paenibacillus anaericanus sp. nov., respectively. MH72 is considered a new strain of Paenibacillus terrae.
authors.affiliation: Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Horn
authors.affiliation: Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Ihssen
authors.affiliation: Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Carola
authors.initials: C
authors.lastname: Matthies
authors.affiliation: Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schramm
authors.affiliation: Electron Microscopy Laboratory, University of Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Acker
authors.affiliation: Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Harold L
authors.initials: HL
authors.lastname: Drake
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D000818:Animals; D015373:Bacterial Typing Techniques; D001482:Base Composition; D020562:Betaproteobacteria / Q000145:classification* / Q000166:cytology / Q000302:isolation & purification / Q000502:physiology; D045304:Cytochromes c / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D004064:Digestive System / Q000382:microbiology; D004725:Endospore-Forming Bacteria / Q000145:classification* / Q000166:cytology / Q000302:isolation & purification / Q000502:physiology; D005417:Flavobacterium / Q000145:classification* / Q000166:cytology / Q000302:isolation & purification / Q000502:physiology; D020459:Genes, rRNA; D005840:Gentian Violet; D006863:Hydrogen-Ion Concentration; D008124:Locomotion; D008969:Molecular Sequence Data; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D009609:Nitrous Oxide / Q000378:metabolism*; D009835:Oligochaeta / Q000382:microbiology*; D010084:Oxidation-Reduction; D010619:Phenazines; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; C035863:Gram's stain; D009566:Nitrates; D010619:Phenazines; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D045304:Cytochromes c; D005840:Gentian Violet; D009609:Nitrous Oxide; D009584:Nitrogen