Ottowia thiooxydans gen. nov., sp. nov., a novel facultatively anaerobic, N2O-producing bacterium isolated from activated sludge, and transfer of Aquaspirillum gracile to Hylemonella gracilis gen. nov., comb. nov.

Abstract

Strain K11T was isolated from activated sludge of a municipal wastewater-treatment plant. Phylogenetic analysis of the 16S rRNA gene sequence revealed that it represents a distinct line of descent within the Comamonadaceae. The novel strain was a Gram-negative, catalase- and oxidase-positive, non-motile, straight to slightly curved rod. Polyhydroxyalkanoate granules were stored intracellularly as reserve material. Colonies on agar plates were small, regular and characterized by a water-insoluble yellow pigment. Unbranched fatty acids 16 : 1ω7c, 16 : 0 and 18 : 1ω7c dominated the cellular fatty acid pattern and ubiquinone-8 (Q-8) was the major component of the respiratory lipoquinones, both traits typical of members of the Comamonadaceae. A distinguishing characteristic was the presence of the two hydroxy fatty acids 10 : 0 3-OH and 12 : 0 2-OH, each in significant amounts. The G+C content of the DNA was 59 mol%. Strain K11T was capable of aerobic chemolithoheterotrophic growth using thiosulfate as an additional substrate, but could not grow autotrophically with thiosulfate or hydrogen. Facultative anaerobic growth was possible with nitrate and nitrite as electron acceptors, but not with ferric iron, sulfate or by fermentation. The sole end product of denitrification was N2O; nitrite accumulated only transiently in small amounts. Based upon phylogenetic and phenotypic evidence, it is proposed to establish the novel taxon Ottowia thiooxydans gen. nov., sp. nov., represented by the type strain K11T (=DSM 14619T=JCM 11629T). Aquaspirillum gracile was among the phylogenetically most closely related species to strain K11T. This species has been wrongly classified, and it is proposed to reclassify it as Hylemonella gracilis gen. nov., comb. nov. The type strain is ATCC 19624T (=DSM 9158T).

Ottowia beijingensis sp. nov., isolated from coking wastewater activated sludge, and emended description of the genus Ottowia

“…The DNA G+C content of the new isolate GCS-AN-3 T was 67.6 mol%, which was in the range previously reported for species of the genus Ottowia (59-68.5 mol%) (Felföldi et al, 2011). (Hylemon et al, 1973;Spring et al, 2004). Data for API 20NE and API ZYM tests for strains 1, 2 and 3 were obtained at the same time in this study; data from references is shown in parentheses where different.…”

“…The description of the genus Ottowia is as given by Spring et al (2004), with the following amendments. Major cellular fatty acids are C 16 : 0 and summed feature 8 (C 18 : 1 v7c/C 18 : 1 v6c).…”

“…The genus Ottowia, belonging to the family Comamonadaceae, was proposed by Spring et al (2004) and it currently comprises two recognized species, Ottowia thiooxydans (Spring et al, 2004) and Ottowia pentelensis (Felföldi et al, 2011); both of them were isolated from activated sludge. In this study, we describe a novel strain, GCS-AN-3 T , isolated from a phenol-degrading consortium, enriched from coking wastewater activated sludge of Beijing Shougang Company Limited (Cao et al, 2011).…”

“…For detection of polyhydroxyalkanoate granules, cells were stained with Sudan Black B (Thakor et al, 2003). Thiosulfate oxidation was tested according to the method of Spring et al (2004). Other biochemical tests were carried out using API 20NE and API ZYM strips (bioMérieux) and Biolog GN2 according to the manufacturers' instructions.…”

Proposal of Giesbergeria voronezhensis gen. nov., sp. nov. and G. kuznetsovii sp. nov. and reclassification of [Aquaspirillum] anulus, [A.] sinuosum and [A.] giesbergeri as Giesbergeria anulus comb. nov., G. sinuosa comb. nov. and G. giesbergeri comb. nov., and [Aquaspirillum] metamorphum and [A.] psychrophilum as Simplicispira metamorpha gen. nov., comb. nov. and S. psychrophila comb. nov.

“…Data are from this study and Krieg (1984). Krieg (1984), Wen et al (1999), Khan & Hiraishi (2002), Mechichi et al (2003) and Spring et al (2004 Hylemon et al 1973(Approved Lists 1980. The description is identical to the description given for Aquaspirillum sinuosum by Hylemon et al (1973).…”