Type genome is Fontibacterium africanum N-Mw6-13nov23-081 (GCA_965235885.1), a metagenome-assembled genome (MAG) assembled from 50 m depth from Lake Malawi, Malawi (date: 2023-11-13). N-Mw6-13nov23-081 has a genome size of 1.1 Mbp with a genomic GC content of 30%, contains 1 rRNA gene (5S rRNA) and 28 tRNAs. The genome is of high quality, consisting of 7 contigs, with a completeness of 95.2%, contamination of 0% and strain heterogeneity of 0% as assessed with checkM. The metagenome was assembled with FLYE from combined long- and short-read sequencing (Oxford Nanopore and Illumina NovaSeq). Metagenomic fragment recruitment of >600 samples from five continents indicate that the species is present only in the African Great Lakes Malawi, Tanganyika, and Kivu. The closest cultivated relatives are Fontibacterium commune, syn. ‘Candidatus Fonsibacter ubiquis’ LSUCC0530 (GCF_002688585.1; later reclassified to ‘Ca. Allofontibacter communis’), with an average amino acid identity of 68.64 % and average nucleotide identity of 71.78 % and another newly proposed species, Fontibacterium abundans MiE-29 (GCA_965235095.1), with an AAI of 68.51 % and an ANI of 71.6 %. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__Fonsibacter; s__Fonsibacter sp016882225.