Phylogenetic diversity, polyamine pattern and DNA base composition of members of the order Planctomycetales

Abstract

The 16s rDNA sequences of 20 novel isolates of members of the order Planctomycetales were compared to those of the type strains of described planctomycete species and 22 planctomycete isolates for which the 16s rDNA sequences had been previously determined. The novel isolates could be assigned to several phylogenetically broad groups, four of which are defined by the genera Gemmata, lsosphaera, Planctomyces and Pirellula. To evaluate polyamines as a chemotaxonomic marker within this order, the polyamine pool was determined for six planctomycete reference species and for 20 planctomycete isolates. All analysed members of the order Planctomycetales contained significant amounts of polyamines. sym-Homospermidine (HSPD) is present in all strains except Planctomyces limnophilus and related strains, which had high amounts of putrescine (PUT) as the dominant polyamine component. The distribution of PUT, HSPD and spermidine reflects the phylogenetic diversity within the Planctomycetales as closely related representatives of the phylogenetic groups defined by described species and novel isolates exhibit similar polyamine patterns. Determination of the DNA base composition revealed G+C contents of >60 m o l % for members of Gemmafa and lsosphaera whereas, except for two isolates, strains which are phylogenetically associated with Planctomyces and Pirellula had G+C contents of 51-57 mol%.~~

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

“…There are obvious morphological similarities between these ' N. limicola ' III isolates and the published description of I. pallida (Staley et al, 1992), although none of the isolates obtained here could grow on the 31PY or 1aPY media of Schlesner (1994) used by Griepenburg et al (1999) to culture their isolates of I. pallida. Furthermore, none of the isolates grew above 40 mC and none appeared to glide and exhibit phototactic behaviour, determined using the methods described by Giovannoni et al (1987), although most seemed to grow best at low concentrations ( 0n1%) of -arabinose in SR2A agar (J.-R. Liu, unpublished).…”

“…3). A high GjC content of the 16S rRNA gene of Isosphaera, considered to be characteristic of this genus alone among the planctomycetes (Griepenburg et al, 1999), was also noticed with the ' N. limicola ' III isolates here (i.e. all between 60 and 62 mol %).…”

Taxonomic heterogeneity within the Planctomycetales as derived by DNA–DNA hybridization, description of Rhodopirellula baltica gen. nov., sp. nov., transfer of Pirellula marina to the genus Blastopirellula gen. nov. as Blastopirellula marina comb. nov. and emended description of the genus Pirellula

“…At present, it is generally accepted that individual species of the same genus should have 16S rRNA gene sequence similarity of more than 95 % (Devereux et al, 1990;Fry et al, 1991;Stackebrandt & Goebel, 1994). The 16S rRNA gene sequence heterogeneity was further supported by analysis of the cell-wall components (König et al, 1984;Liesack et al, 1986), phospholipids (Kerger et al, 1988;Sittig & Schlesner, 1993) and polyamines (Griepenburg et al, 1999). …”

“…The chemotaxonomic markers that have been analysed are the fatty acid and phospholipid profiles (Kerger et al, 1988;Sittig & Schlesner, 1993), the amino acid composition of cell walls (König et al, 1984;Liesack et al, 1986) and the polyamine patterns (Griepenburg et al, 1999). In contrast, analysis of the quinone profile was not useful within the group, since all planctomycetes investigated so far have possessed MK-6 as the only quinone (Sittig & Schlesner, 1993; B. J. Tindall & H. Schlesner, unpublished).…”

“…Studies on the evolutionary position of these organisms indicated a great inter-and intrageneric heterogeneity in the 16S rRNA gene sequences (Stackebrandt et al, 1986;Ward et al, 1995;Fuerst et al, 1997;Griepenburg et al, 1999). Sequence-similarity values for the 16S rRNA genes of Pirellula staleyi, Pirellula marina (here described as Blastopirellula marina gen. nov., comb.…”