Planctoellipticum variicoloris gen. nov., sp. nov., a novel member of the family Planctomycetaceae isolated from wastewater of the aeration lagoon of a sugar processing plant in Northern Germany

Abstract In the present study, we characterise a strain isolated from the wastewater aeration lagoon of a sugar processing plant in Schleswig (Northern Germany) by Heinz Schlesner. As a pioneer in planctomycetal research, he isolated numerous strains belonging to the phylum Planctomycetota from aquatic habitats around the world. Phylogenetic analyses show that strain SH412 T belongs to the family Planctomycetaceae and shares with 91.6% the highest 16S rRNA gene sequence similarity with Planctopirus limnophila DSM 3776 T . Its genome has a length of 7.3 Mb and a G + C content of 63.6%. Optimal growth of strain SH412 T occurs at pH 7.0–7.5 and 28 °C with its pigmentation depending on sunlight exposure. Strain SH412 T reproduces by polar asymmetric division (“budding”) and forms ovoid cells. The cell size determination was performed using a semi-automatic pipeline, which we first evaluated with the model species P. limnophila and then applied to strain SH412 T . Furthermore, the data acquired during time-lapse analyses suggests a lifestyle switch from flagellated daughter cells to non-flagellated mother cells in the subsequent cycle. Based on our data, we suggest that strain SH412 T represents a novel species within a novel genus, for which we propose the name Planctoellipticum variicoloris gen. nov., sp. nov., with strain SH412 T (= CECT 30430 T = STH00996 T , the STH number refers to the Jena Microbial Resource Collection JMRC) as the type strain of the new species.