Type species is Pernthalerella aquatica GE-M3 (GCA_965194445.1), isolated from 5 m depth from Greifensee, Switzerland (date: 2019-04-03), via high-throughput dilution to extinction cultivation. GE-M3 has a genome size of 3.1 Mbp with a genomic GC content of 53.8%, contains 3 rRNA genes and 41 tRNAs. The genome is a high-quality draft consisting of 7 contigs. The genome contains genes encoding anoxygenic aerobic phototrophy (pufABLM) and the complete Calvin cycle for carbon fixation via RuBisCO. Genes for flagellar and pilus assembly were annotated. Pathways for urea degradation, glycolate oxidation and the biosynthesis of all amino acids were predicted. Further, pathways for thiamine, riboflavin, NAD, pantothenate, coenzyme A, biotin, THF, and heme biosynthesis were identified. The closest cultivated relative is Paucimonas lemoignei DSM 7445 (GCF_004342585.1) with an average amino acid identity of 64.5% and average nucleotide identity of 71.1% and two other newly proposed species, Pernthalerella lacuna MaE-M21 (GCA_965194545.1) and Pernthalerella communis MsE-6 (GCA_965194595.1), with AAI of 72.1-73.1% and ANI of 71.9-72.5%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Gammaproteobacteria; o__Burkholderiales; f__Burkholderiaceae; g__SYFN01; s__.