'Candidatus Nostocoida limicola', a filamentous bacterium from activated sludge.

Five strains of 'Candidatus Nostocoida limicola' were isolated by micromanipulation from two activated sludge plants. Two (Ben17 and Ben18) were from Sunbury, Victoria, Australia, and three (Ben67, Ver1 and Ver2) were from Verona, Italy. The near complete 16S rDNA sequences were determined for five strains and the phylogenetic location of this important bulking filament in the actinomycete subphylum is reported for the first time. Phylogenetically, the Ben strains formed one group with 99.4% 16S rDNA similarity, and the Ver strains formed another with 99.9% 16S rDNA similarity. The mean similarity between the two groups was 97.4%. By 16S rDNA comparison, the closest relative to all strains was Terrabacter sp. strain DPO1361 (95.0-95.5% identical). On R2A medium, all strains generally grew as short filaments or clumps of cocci, whereas on glucose sulfide (GS) medium, all grew as irregular twisting filaments comprising Gram-positive and Gram-negative cells, which is close to their in situ morphology. Polyphosphate was stored either as granules (R2A) or throughout the trichomes (GS). None of the strains could grow without added nitrogen, reduce nitrate to nitrogen gas or grow anaerobically, whereas all could grow at 15-30 degrees C, produce catalase and reduce nitrate to nitrite. All were inactive in the Hugh & Leifson test. This paper describes 'Candidatus Nostocoida limicola'.

Blackall LL ，Seviour EM ，Bradford D ，Rossetti S ，Tandoi V ，Seviour RJ ... -  《international journal of systematic and evolutionary microbiology》

Isolates of 'Candidatus Nostocoida limicola' Blackall et al. 2000 should be described as three novel species of the genus Tetrasphaera, as Tetrasphaera jenkinsii sp. nov., Tetrasphaera vanveenii sp. nov. and Tetrasphaera veronensis sp. nov.

Despite differences in their morphologies, comparative analyses of 16S rRNA gene sequences revealed high levels of similarity (>94 %) between strains of the filamentous bacterium 'Candidatus Nostocoida limicola' and the cocci Tetrasphaera australiensis and Tetrasphaera japonica and the rod Tetrasphaera elongata, all isolated from activated sludge. These sequence data and their chemotaxonomic characters, including cell wall, menaquinone and lipid compositions and fingerprints of their 16S-23S rRNA intergenic regions, support the proposition that these isolates should be combined into a single genus containing six species, in the family Intrasporangiaceae in the Actinobacteria. This suggestion receives additional support from DNA-DNA hybridization data and when partial sequences of the rpoC1 gene are compared between these strains. Even though few phenotypic characterization data were obtained for these slowly growing isolates, it is proposed, on the basis of the extensive chemotaxonomic and molecular evidence presented here, that 'Candidatus N. limicola' strains Ben 17, Ben 18, Ben 67, Ben 68 and Ben 74 all be placed into the species Tetrasphaera jenkinsii sp. nov. (type strain Ben 74(T)=DSM 17519(T)=NCIMB 14128(T)), 'Candidatus N. limicola' strain Ben 70 into Tetrasphaera vanveenii sp. nov. (type strain Ben 70(T)=DSM 17518(T)=NCIMB 14127(T)) and 'Candidatus N. limicola' strains Ver 1 and Ver 2 into Tetrasphaera veronensis sp. nov. (type strain Ver 1(T)=DSM 17520(T)=NCIMB 14129(T)).

McKenzie CM ，Seviour EM ，Schumann P ，Maszenan AM ，Liu JR ，Webb RI ，Monis P ，Saint CP ，Steiner U ，Seviour RJ ... -  《international journal of systematic and evolutionary microbiology》

Phylogeny of the filamentous bacterium 'Nostocoida limicola' III from activated sludge.

:Five strains of the filamentous bacterium 'Nostocoida limicola' III were successfully isolated into pure culture from samples of activated sludge biomass from five plants in Australia. 16S rRNA gene sequence analyses showed that all isolates were members of the Planctomycetales, most closely related to Isosphaera pallida, but they differed phenotypically from this species in that they did not glide and were not thermotolerant. The ultrastructure of these 'N. limicola' III isolates was also consistent with them being Planctomycetales, in that they possessed complex intracellular membrane systems compartmentalizing the cells. However, the arrangements of these intracellular membranes differed between isolates. These data confirm that 'N. limicola' III is phylogenetically unrelated to both 'N. limicola' I and 'N. limicola' II, activated sludge filamentous bacteria which share morphological features in common with 'N. limicola' III and which have been presumed historically to be the same or very similar bacteria.

Liu JR ，McKenzie CA ，Seviour EM ，Webb RI ，Blackall LL ，Saint CP ，Seviour RJ ... -  《international journal of systematic and evolutionary microbiology》

Three isolates of novel polyphosphate-accumulating gram-positive cocci, obtained from activated sludge, belong to a new genus, Tetrasphaera gen. nov., and description of two new species, Tetrasphaera japonica sp. nov. and Tetrasphaera australiensis sp. no

Two isolates of Gram-positive cocci (Ben 109T and Ben 110) which could accumulate polyphosphate and were microscopically similar in appearance to so-called 'G-bacteria', appearing as tetrads, were isolated from samples of activated sludge biomass by micromanipulation and grown in axenic culture. On the basis of their phenotypic and chemotaxonomic characters and 16S rDNA sequences, these isolates, together with strain T1-X7T isolated and described previously in Japan, belong to a new genus. These isolates are phylogenetically different from Tessaracoccus bendigoensis, Friedmanniella spumicola and Friedmanniella capsulata, Gram-positive cocci isolated previously in this laboratory. They are characterized by type A1 gamma peptidoglycan, with meso-diaminopimelic acid as the diagnostic diamino acid. The main cellular fatty acid of Ben 109T, Ben 110 and T1-X7T is 14-methylpentadecanoic acid (i-C16:0). The major menaquinones of Ben 109T are MK-8(H4), with MK-8(H2) and MK-8 in trace amounts. In Ben 110 MK-8(H4) and MK-6(H4) are the major menaquinones, while T1-X7T has MK-8(H4), MK-7(H4) and MK-6(H4) as its menaquinones. All three contain phosphatidylinositol, phosphatidylglycerol and diphosphatidylglycerol as their polar lipids. These properties, together with 16S rDNA sequence data, suggest that they all belong to a single new genus for which the name Tetrasphaera gen. nov. is proposed. However, the lipid, cellular fatty acid profiles and DNA-DNA similarity data suggest that Ben 109T and Ben 110 are sufficiently different from T1-X7T to represent a different species of the genus Tetrasphaera. Strain T1-X7T represents the type species Tetrasphaera japonica sp. nov. of this new genus, and strains Ben 109T and Ben 110 belong to the other species, Tetrasphaera australiensis sp. nov.

Maszenan AM ，Seviour RJ ，Patel BK ，Schumann P ，Burghardt J ，Tokiwa Y ，Stratton HM ... -  《international journal of systematic and evolutionary microbiology》

Candidatus Monilibacter spp., common bulking filaments in activated sludge, are members of Cluster III Defluviicoccus.

Two alphaproteobacterial Neisser negative 'Nostocoida limicola' morphotypes differing slightly in their trichome diameter and filament regularity were dominant populations in the Bendigo, Victoria, Australia activated sludge community removing phosphorus (P). Neither responded to the FISH probes available for any of the other alphaproteobacterial 'N. limicola' morphotypes. Instead both fluoresced with the DF988 FISH probe designed originally to target alphaproteobacterial cluster II Defluviicoccus tetrad forming organisms. A 16S rRNA based clone library from this biomass revealed that the alphaproteobacterial clones grouped closely with Candidatus 'Monilibacter batavus' and Defluviicoccus clones in a cluster separate from the existing cluster I and II Defluviicoccus. When a FISH probe was designed against these, it only hybridized to the thinner and less abundant 'N. limicola' morphotype. Micromanipulation-RT-PCR was used to selectively recover the main 'N. limicola' morphotype and a FISH probe designed against the 16S rRNA clones generated from it showed only this filament fluoresced. From FISH based surveys, both 'N. limicola' variants occurred frequently in phosphorus removal activated sludge systems in Australia treating domestic waste. The data suggest that they represent two new strains of Candidatus 'Monilibacter', which on this evidence are filamentous members of the genus Defluviicoccus, a potential competitor for the polyphosphate accumulating organisms in these communities.

Nittami T ，McIlroy S ，Seviour EM ，Schroeder S ，Seviour RJ ... -  《-》