The 16S rDNAs from 38 strains of the genus Nocardioides, two Aeromicrobium species and Terrabacter tumescens were directly sequenced and then analysed. The mean nucleotide similarity value between the type strains of validly described Nocardioides species was 96.1 +/- 3.0%. The mean nucleotide similarity value between the type strains of validly described Nocardioides species and the two Aeromicrobium species was 93.7 +/- 1.4% T. tumescens was distantly related to the genera Nocardioides and Aeromicrobium. The mean intraspecific nucleotide similarity value of 16S rDNA sequences from Nocardioides albus was 99.5 +/- 0.5%. The mean intraspecific nucleotide similarity of 16S rDNA sequences from Nocardioides simplex was 100%, except for N. simplex strains ATCC 13260, ATCC 19565 and ATCC 19566, which were shown not to be members of the genus Nocardioides. 'Nocardioides flavus' strains IFO 14396T and IFO 14397, and 'Nocardioides fulvus' JCM 3335T showed a 16S rDNA similarity value of 100% with Nocardioides luteus KCTC 9575T and Nocardioides albus JCM 5854. 'N. fulvus' IFO 14399 shared its highest 16S rDNA similarity with Nocardioides sp. ATCC 39419 at 99%. 'N. fulvus' IFO 14399 and Nocardioides sp. ATCC 39419 formed a phylogenetic lineage distinct from the genera Nocardioides and Aeromicrobium. 'Nocardioides thermolilacinus' strains IFO 14335T and IFO 14336 displayed a close relationship to the genus Streptomyces. From 16S rDNA sequence analyses, it is considered that some strains that have been attributed to the genus Nocardioides should be taxonomically re-evaluated.

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The ammonium-oxidizing microbial community was investigated in a granular sludge anaerobic ammonium-oxidizing (anammox) reactor that was operated for about 1 year with high anaerobic ammonium oxidation activity (up to 0.8 kg NH(4)(+)-N m(-3) day(-1)). A Planctomycetales-specific 16S rRNA gene library was constructed to analyse the diversity of the anaerobic ammonium-oxidizing bacteria (AnAOB). Most of the specifically amplified sequences (15/16) were similar to each other (> 99%) but were distantly related to all of the previously recognized sequences (< 94%), with the exception of an unclassified anammox-related clone, KSU-1 (98%). An ammonia monooxygenase (amoA) gene library was also analysed to investigate the diversity of 'aerobic' ammonium-oxidizing bacteria (AAOB) from the beta-Proteobacteria. Most of the amoA gene fragments (53/55) clustered in the Nitrosomonas europaea-Nitrosococcus mobilis group which has been reported to prevail under oxygen-limiting conditions. The quantitative results from real-time polymerase chain reaction (PCR) amplification showed that the dominant AnAOB comprised approximately 50% of the total bacterial 16S rRNA genes in the reactor, whereas the AAOB of beta-Proteobacteria represented only about 3%. A large fragment (4008 bp) of the rRNA gene cluster of the dominant AnAOB (AS-1) in this reactor sludge was sequenced and compared with sequences of other Planctomycetales including four anammox-related candidate genera. The partial sequence of hydrazine-oxidizing enzyme (hzo) of dominant AnAOB was also identified using new designed primers. Based on this analysis, we propose to tentatively name this new AnAOB Candidatus'Jettenia asiatica'.

3 Japan Collection of A p-nitrophenol-degrading bacterial strain was isolated from industrial wastewater. This strain (NSP413 was identified as a member of the genus Nocardioides from c hemotaxonom i c characterizations and p h y I og enet ic inference based on 165 rDNA sequence analysis. The G+C content is 71.4 mol%.The diamino acid in the cell-wall peptidoglycan is u-diaminopimelic acid. The predominant menaquinone is MK=8(HJ. The cellular fatty acid profile is similar to those of Nocardioides species. 165 rDNA sequence analysis show that strain NSP41T is the most related to Nocardioides simplex strains with a level of nucleotide similarity of 986%. The levels of 165 rDNA similarity between strain NSP4V and other Nocardioides species ranged from 93.8 to 95.1 %. This organism is distinguishable from some other Nocardioides species as well as N.simplex strains by DNA-DNA relatedness data. This organism is different from N. simplex strains in some phenotypic characteristics. Therefore, on the basis of the data presented, a new species of the genus Nocardioides, Nocardioides nitrophenolicus, is proposed. The type strain of the new species i s strain NSP41T (= KCTC 0457BP3.

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