Etymology. It is named ‘alpinus’ after the isolation source of 2 strains of this species, Lake Gossenkollesee, a high alpine mountain lake in Austria.
Brief description. The type species is Planktophila alpinus PaE-42 (ENA accession number GCA_965267995), isolated from the epilimnion (5 m depth) of Lake Pavin, France (date: 2022-05-24) via high-throughput dilution to extinction cultivation. Other two strains were isolated in our laboratory from the epilimnion (5m depth) and hypolimnion (8m depth) of Lake Gossenkollesee, Austria. The genome size of the type strain PaE-42 is 1,467,434 bp and has a GC content of 41%, encoding for one rRNA operon and 41 tRNAs. The genome is complete, consisting of a circular chromosome. The genome contains genes encoding rhodopsins. No genes for flagella, pilus assembly or chemotaxis were annotated. The closest isolated relative of this species is Planktophila aquatilis IMCC26103, isolated from Lake Soyang (South Korea), with whom it shares an average nucleotide identity of 89.4%. The Current GTDB classification (r220) is d__Bacteria; p__Actinomycetota; c__Actinomycetia; o__Nanopelagicales; f__Nanopelagicaceae; g__Planktophila; s__.