title: Pelotomaculum terephthalicum sp. nov. and Pelotomaculum isophthalicum sp. nov.: two anaerobic bacteria that degrade phthalate isomers in syntrophic association with hydrogenotrophic methanogens.
abstract: An anaerobic phthalate isomer-degrading strain (JT(T)) that we previously isolated was characterized. In addition, a strictly anaerobic, mesophilic, syntrophic phthalate isomer-degrading bacterium, designated strain JI(T), was isolated and characterized in this study. Both were non-motile rods that formed spores. In both strains, the optimal growth was observed at temperatures around 37 degrees C and neutral pH. In syntrophic co-culture with the hydrogenotrophic methanogen Methanospirillum hungatei, both strains could utilize two or three phthalate isomers for growth, and produce acetate and methane as end products. Strain JT(T) was able to grow on isophthalate, terephthalate, and a number of low-molecular weight aromatic compounds, such as benzoate, hydroquinone, 2-hydroxybenzoate, 3-hydroxybenzoate, 2,5-dihydroxybenzoate, 3-phenylpropionate in co-culture with M. hungatei. It could also grow on crotonate, hydroquinone and 2,5-dihydroxybenzoate in pure culture. Strain JI(T) utilized all of the three phthalate isomers as well as benzoate and 3-hydroxybenzoate for growth in co-culture with M. hungatei. No substrates were, however, found to support the axenic growth of strain JI(T). Neither strain JT(T) nor strain JI(T) could utilize sulfate, sulfite, thiosulfate, nitrate, fumarate, Fe (III) or 4-hydroxybenzoate as electron acceptor. Phylogenetically, strains JT(T) and JI(T) were relatively close to the members of the genera Pelotomaculum and Cryptanaerobacter in 'Desulfotomaculum lineage I'. Physiological and chemotaxonomic characteristics indicated that the two isolates should be classified into the genus Pelotomaculum, creating two novel species for them. Here, we propose Pelotomaculum terephthalicum sp. nov. and Pelotomaculum isophthalicum sp. nov. for strain JT(T) and strain JI(T), respectively. The type strains are strains JT(T) (= DSM 16121(T )= JCM 11824(T )= NBRC 100523(T)) and JI(T) (= JCM 12282(T) = BAA-1053(T)) for P. terephthalicum and P. isophthalicum, respectively.
authors.affiliation: Institute of Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, 305-8566 Tsukuba, Ibaraki, Japan.
authors.forename: Yan-Ling
authors.initials: YL
authors.lastname: Qiu
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sekiguchi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hanada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Imachi
authors.forename: I-Cheng
authors.initials: IC
authors.lastname: Tseng
authors.forename: Sheng-Shung
authors.initials: SS
authors.lastname: Cheng
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Ohashi
authors.forename: Hideki
authors.initials: H
authors.lastname: Harada
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Kamagata
mesh_terms: D000693:Anaerobiosis; D015373:Bacterial Typing Techniques; D001673:Biodegradation, Environmental; D018920:Coculture Techniques; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis; D006859:Hydrogen / Q000378:metabolism*; D007536:Isomerism; D008697:Methane / Q000378:metabolism*; D019639:Methanospirillum / Q000254:growth & development* / Q000378:metabolism; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010459:Peptococcaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology; D010795:Phthalic Acids / Q000378:metabolism*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D010795:Phthalic Acids; D012336:RNA, Ribosomal, 16S; C059768:isophthalate; C032279:phthalic acid; C011363:terephthalic acid; D006859:Hydrogen; D008697:Methane