Genomic and functional insights of a mucin foraging Rhodopirellula halodulae sp. nov.

Nine novel strains were obtained from various algal and seagrass samples. The analysis of the 16S rRNA gene-based phylogenetic tree revealed monophyletic placement of all novel strains within the Rhodopirellula genus. The type strain was identified as JC737T, which shared 99.1 % 16S rRNA gene sequence identity with Rhodopirellula baltica SH1T, while strain JC740 was designated as an additional strain. The genome sizes of strains JC737T and JC740 were 6.6 and 6.7 Mb, respectively, and the G + C content was 56.2 %. The strains cladded distinctly in the phylogenomic tree, and the ANI and dDDH values of the strain JC737T were 75.8-76.1 % and 20.8-21.3 %, respectively, in comparison to other Rhodopirellula members. The strain demonstrated a versatile degradation capability, exhibiting a diverse array of complex polysaccharides, including mucin which had not been previously identified within the members of the phylum Planctomycetota. The phylogenomic, pan-genomic, morphological, physiological, and genomic characterization of the strain lead to the proposal to describe the strain as Rhodopirellula halodulae sp. nov.

Blastopirellula sediminis sp. nov. a new member of Pirellulaceae isolated from the Andaman and Nicobar Islands.

Two cream-coloured strains (JC732T, JC733) of Gram-stain negative, mesophilic, catalase and oxidase positive, aerobic bacteria which divide by budding, form crateriform structures, and cell aggregates were isolated from marine habitats of Andaman and Nicobar Islands, India. Both strains had genome size of 7.1 Mb and G + C content of 58.9%. Both strains showed highest 16S rRNA gene-based similarity with Blastopirellula retiformator Enr8T (98.7%). Strains JC732T and JC733 shared 100% identity of 16S rRNA gene and genome sequences. The coherence of both strains with the genus Blastopirellula was supported by the 16S rRNA gene based and the phylogenomic trees. Further, the chemo-taxonomic characters and the genome relatedness indices [ANI (82.4%), AAI (80.4%) and dDDH (25.2%)] also support the delineation at the species level. Both strains have the capability to degrade chitin and genome analysis shows the ability to fix N2. Based on the phylogenetic, phylogenomic, comparative genomic, morphological, physiological, and biochemical characteristics, strain JC732T is described as a new species of the genus Blastopirellula for which the name Blastopirellula sediminis sp. nov. is proposed, with strain JC733 as an additional strain.

Crateriforma spongiae sp. nov., isolated from a marine sponge and emended description of the genus "Crateriforma".

A Gram-stain-negative, aerobic, pear to oval shaped, rosette forming bacterium with crateriform structures well distributed on the cell surface designated as strain JC647T was isolated from a sponge specimen belonging to the genus Spongia. Strain JC647T reproduces through budding. Strain JC647T shared highest 16S rRNA gene sequence identity of 99.9% with "Crateriforma conspicua" Mal65T (not a valid species name). The genome size of strain JC647T is 6.9 Mb with a G + C content of 57.8 mol %. For the resolution of the phylogenetic congruence of the novel strain, the phylogeny was also constructed with the sequences of ninety-two housekeeping genes. Based on the phylogenetic analyses, low dDDH value (51.0%), low gANI (93.2%), low AAI (94.9%) results, chemotaxonomic characteristics and differential physiological properties, strain JC647T is recognized as a new species of the genus "Crateriforma", for which we propose the name Crateriforma spongiae sp. nov. The type species is JC647T (= KCTC 72176T = NBRC 114068T).