A novel strain isolated from methane seeps in the Kattegat belongs to the planctomycetal species Novipirellula methanifontis sp. nov.

Here, we present the bacterial isolate SH528T, a planctomycetal strain from the collection of Heinz Schlesner (Kiel University), a pioneer in the research on budding bacteria. Genomic and physiological features of the novel strain are characterized along with an analysis of its phylogenetic position within the phylum Planctomycetota. Strain SH528T was isolated from the methane seeps of the Kattegat, a strait between Denmark and Sweden. It forms salmon-pigmented, ellipsoidal cells that divide asymmetrically by polar budding, the common cell division mode in the class Planctomycetia. Physiological analyses of the aerobic heterotroph revealed a mesophilic and neutrophilic lifestyle. Despite the isolation from a methane-rich environment, the strain is not a methanotroph. With a length of 10.5 Mb, the strain has a relatively large genome, even for members of the phylum Planctomycetota, and a DNA G + C content of 54.1%. Phylogenetic analyses using five established single gene- or genome-based markers place the strain in the family Pirellulaceae and support its delineation from the described species of the genus Novipirellula. We thus propose to assign the strain to a novel species for which we introduce the name Novipirellula methanifontis sp. nov. The novel taxon is represented by SH528T (= DSM 116128T = KCTC 102012T) as the type strain.