The novel genus Brakhagea gen. nov. is constituted by four planctomycetal species isolated from aquatic environments in Northern Germany.

Four budding and pink-pigmented planctomycetal strains, designated SH449T, SH551T, SH467T, and SH501T, were isolated from diverse environmental sources, including Fjord Schlei (a 42 km brackish arm of the Baltic Sea), ponds and wastewater lagoons in Northern Germany, as part of an isolation campaign led by Heinz Schlesner at Kiel University between the 1980s and early 2000s. Analyses based on five phylogenetic markers indicate that these strains constitute a novel genus within the family Pirellulaceae of the phylum Planctomycetota. All four strains are aerobic, heterotrophic, mesophilic, and exhibit neutrophilic properties. Strains SH551T and SH501T possess at least one plasmid that is not present in the other two strains. Genome analyses revealed that their genomes are of comparable size to those of other members of the Pirellulaceae family, exhibiting a DNA G + C content ranging from 49 to 54%. Analysis of predicted biosynthetic gene clusters shows that all four strains possess the genetic potential to produce bioactive compounds and may therefore be regarded as putative “talented producers”. The polyphasic approach places all four novel strains in a new genus within the family Pirellulaceae, for which the name Brakhagea gen. nov. is proposed. The novel isolates represent four distinct novel species, Brakhagea baltica sp. nov. (type strain SH449T = KCTC 102025T = DSM 116586T), Brakhagea lacunae sp. nov. (type strain SH551T = KCTC 102023T = DSM 116785T = CECT 30846T), Brakhagea slesvicensis sp. nov. (type strain SH467T = KCTC 102026T = DSM 116378T), and Brakhagea aquatica sp. nov. (type strain SH501T = DSM 102088T = CECT 30906T).