Three strains isolated from Northern Germany constitute the novel genera Njordella and Rania in the family Pirellulaceae

Abstract

Abstract This study reports the characterization of three novel species belonging to the two newly established genera Njordella gen. nov. and Rania gen. nov. in the family Pirellulaceae within the phylum Planctomycetota . The three investigated strains SH302 T , SH451 T and SH573 T were isolated from water samples originating from distinct locations across Northern Germany: Lägerdorf (a municipality close to Hamburg), Fjord Schlei (a 42 km estuary of the Baltic Sea) and Fehmarn Island in the Baltic Sea. All strains form (light) pink colonies, reproduce asymmetrically by polar budding and display an acorn-shaped cell morphology typical in the family Pirellulaceae . Rosette formation was only observed for strains SH302 T and SH573 T . The three strains are mesophilic with a temperature optimum at 28 °C, aerobic and heterotrophic, but differ in their pH preference. While strains SH302 T and SH573 T are neutrophilic (pH optimum at 7.0 and 7.5, respectively), strain SH451 T is slightly alkaliphilic (optimal growth at pH 8.0). The genome sizes of strains SH302 T , SH451 T and SH573 T are 7.2 Mb, 6.6 Mb and 9.4 Mb, respectively. Based on phylogenetic, morphological and physiological analyses, we conclude that the novel strains belong to three novel species of two novel genera. For the novel taxa, we introduce the names Njordella aestuarii gen. nov., sp. nov., represented by strain SH451 T (= CECT 30907 T  = KCTC 102089 T ) as the type strain and Njordella calcicola sp. nov. with type strain SH302 T (= DSM 116728 T  = KCTC 102091 T ). For the third taxon, we chose the name Rania fehmarnensis gen. nov., sp. nov. represented by the type strain SH573 T (= DSM 116763 T  = CECT 31080 T  = KCTC 102135 T ).