Paludisphaera mucosa sp. nov., a Novel Planctomycete of the Family Isosphaeraceae from a Boreal Fen
Anastasia A. Ivanova, D. G. Naumoff, Irina S. Kulichevskaya, Anna Meshcheriakova, Svetlana N. Dedysh
Abstract
Abstract — Planctomycetes are common inhabitants of northern wetland ecosystems. In this study, a new planctomycete of the genus Paludisphaera , strain Pla2 T , was isolated from a boreal fen in Russia. The novel isolate was represented by nonmotile, pink-pigmented, spherical cells that multiplied by budding and occurred singly or were assembled in small aggregates. Strain Pla2 T was a chemoorganotrophic, psychrotolerant mesophile with a growth optimum at pH 5.5‒6 and 15‒20°C. The preferred growth substrates were polysaccharides, including xylan, xanthan gum, and phytagel, as well as some sugars. The 16S rRNA gene sequence of strain Pla2 T displayed the highest similarity (97.9%) to that of ‘ Paludisphaera soli ’ JC670 T isolated from highland soil of the western Himalayas. With other members of the genus Paludisphaera , ‘ P. rhizosphaerae ’ JC665 T and P. borealis PX4 T , this similarity was 97.0 and 93.8%, respectively. The genome of strain Pla2 T was 8.21 Mb in size and contained about 6500 protein-coding genes and 3 copies of the rRNA operon. The DNA G + C content was 67 mol %. The average nucleotide identity between the genome sequence of strain Pla2 T and those of previously described members of the genus Paludisphaera was between 79.4 and 82.6%. This genotypic distance as well as several phenotypic differences allowed classifying the new planctomycete from a fen as representing a novel species of the genus Paludisphaera , Paludisphaera mucosa sp. nov. with the type strain Pla2 T (=KCTC92668 T = VKM B-3698 T ).