# A novel planctomycetotal isolate from subsurface percolates belongs to the novel species Anatilimnocola aquadivae sp. nov. in the family Pirellulaceae

## TL;DR

A new species of bacteria, Anatilimnocola aquadivae, was discovered in underground water in Germany and has unique growth characteristics.

## Contribution

The discovery of a novel Planctomycetota species from terrestrial subsurface percolates expands the known ecological range of the Pirellulaceae family.

## Key findings

- Strain NA78T was isolated from fractured limestone percolates at 0.6 m depth in Germany.
- The strain exhibits pear-shaped cells, asymmetrical division, and optimal growth at 18°C and pH 7.5.
- Genomic analysis confirms NA78T as a novel species in the genus Anatilimnocola.

## Abstract

The family Pirellulaceae (phylum Planctomycetota) is known for its environmental versatility, with members isolated from marine habitats, algal surfaces, soil and lakes; yet, no member has been isolated from terrestrial subsurface habitats. Here, we describe the planctomycetal strain NA78T that was discovered in percolates from fractured limestone in ca. 0.6 m depth at the Hainich Critical Zone Exploratory (CZE) in central Germany. Cells of the isolated strain are pear-shaped, measuring approximately 1.1 × 1.8 μm, and divide by asymmetrical cell division (“polar budding”). Liquid cultures have a whitish color and cells of the strain form aggregates. Colonies are rigid, round and of whitish to beige color. Strain NA78T grows under oxic conditions and thrives at temperatures between 18 and 24 °C, with an optimum at 18 °C. The strain tolerates pH values from 6.0 to 9.0, with optimal growth at pH 7.5, and matches the pH range of the bedrock percolate. Its genome has a size of 7.97 Mbp and a DNA G + C content of 58.2%. From combined results of phylogenetic analyses and phenotypic and genomic characterization, we conclude that strain NA78T belongs to a novel species of the genus Anatilimnocola. We thus introduce the name Anatilimnocola aquadivae sp. nov., represented by NA78T (= CECT 30429T = STH00992T; the STH number refers to the Jena Microbial Resource collection JMRC) as the type strain.

The online version contains supplementary material available at 10.1038/s41598-026-44018-1.