Comparative genome analysis of the genus Hydrotalea and proposal of the novel species Hydrotalea lipotrueae sp. nov., isolated from a groundwater aquifer in the south of Mallorca Island, Spain

From a collection of > 140 strains isolated from groundwater with thermal anomalies for the purpose of obtaining good candidates with applications in the cosmetic industry, two strains were selected because of their taxonomic novelty. Among the isolates, strains TMF_100(T) and TFM_099 stood out for their potential biotechnological relevance, and a comparative analysis of 16S rRNA gene sequences indicated that these strains represented a new species of the genus Hydrotalea. In addition, from the public genomic databases, metagenome-assembled genomes (MAGs) and single-cell amplified genomes (SAGs) could be retrieved that affiliated with this genus. These MAGs and SAGs had been obtained from different environmental samples, such as acid mine drainage or marine sediments. In addition to the description of the new species, the ecological relevance of the members of this genus was demonstrated by means of denitrification, CRISPR-Cas system diversity and heavy metal resistance, as well as their wide geographical distribution and environmental versatility. Supported by the taxonomic study, together with physiological and morphological differences and ecological features, we concluded that strain TMF_100(T) represented a novel species within the genus Hydrotalea, for which we propose the name Hydrotalea lipotrueae sp. nov. (C) 2021 The Author(s). Published by Elsevier GmbH.

Automated summary

This study isolated over 140 strains from groundwater with thermal anomalies, and selected two strains for their taxonomic novelty and potential biotechnological relevance in the cosmetic industry. These strains represented a new species of the genus Hydrotalea, with ecological relevance demonstrated by denitrification, CRISPR-Cas system diversity, heavy metal resistance, and wide geographical distribution.