Register list for 12 new names including Fontibacterium baikalense sp. nov.

Type species is Pelagilacustribacter hypolimneticus TrH-25oct19-165 (GCA_965235125.1), a metagenome-assembled genome (MAG) obtained from 150m depth from Traunsee, Austria. Pelagilacustribacter is a genus within marine SAR11-II (Pelagibacterales) that is found in deep freshwater lakes.

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.

Type genome is Fontibacterium baikalense Baikal-deep-G36 (GCA_009693745.1), a metagenome-assembled genome (MAG) co-assembled from 1250 m and 1350 m depth from Lake Baikal, Russia (date: 2018-03-29). Baikal-deep-G36 has a genome size of 1 Mbp with a genomic GC content of 29.4%, contains 2 rRNA genes and 25 tRNAs. The genome is of high quality, consisting of 66 contigs, with a completeness of 95.2%, contamination of 3.9% and strain heterogeneity of 100% as assessed with checkM. The metagenome was assembled with IDBA-UD assembler from short-read sequencing (Illumina HiSeq 3000/4000). 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 85.75% and average nucleotide identity of 84.65% and another newly proposed species, Fontibacterium medardicus ME-17, with an AAI of 88.73% and an ANI of 87.93%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__Fonsibacter; s__Fonsibacter sp009693745.

Type genome is Fontibacterium boreale Umea-bin-09620 (GCA_903909545.1), a metagenome-assembled genome (MAG) assembled from 1-5 m depth from Lake Bjarntjarnan, Sweden (date: 2018-01-01/07). Umea-bin-09620 has a genome size of 1 Mbp with a genomic GC content of 30.2% and contains 20 tRNAs. The genome is of high quality, consisting of 243 contigs, with a completeness of 96.4%, contamination of 0.1% and strain heterogeneity of 0% as assessed with checkM. The metagenome was assembled with Megahit (version 1.1.13) from short-read sequencing (Illumina MiSeq). Metagenomic fragment recruitment of >600 samples from five continents indicate that the species is present mainly in boreal lakes in Europe and North America. 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 82.49% and average nucleotide identity of 81.54 % and another newly proposed species, Fontibacterium abundans MiE-29 (GCA_965235095.1), with an AAI of 84.48% and an ANI of 83.54 %. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__Fonsibacter; s__.

Type genome is Fontibacterium meridianamericanum N-IMU-22jan24-050 (GCA_965235635.1), a metagenome-assembled genome (MAG) assembled from 0.5 m depth from Represa de India Muerta, a freshwater reservoir in Uruguay (date: 2024-01-22). N-IMU-22jan24-050 has a genome size of 1.0 Mbp with a genomic GC content of 29.3% and contains 30 tRNAs. The genome is of high quality, consisting of 4 contigs, with a completeness of 95.8%, contamination of 1.2% and strain heterogeneity of 100% 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 mainly in subtropical and tropical lakes in South America. 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 86.94% and average nucleotide identity of 84.39% and another newly proposed species, Fontibacterium abundans MiE-29 (GCA_965235095.1), with an AAI of 90.5% and an ANI of 88.11%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__Fonsibacter; s__

Type genome is Fontibacterium oligotrophicum N-Balt2-05jul22-047 (GCA_965235975.1), a metagenome-assembled genome (MAG) assembled from 0.5 m depth from the slightly brackish part of Vistula Lagoon, Poland (date: 2022-07-05). N-Balt2-05jul22-047 has a genome size of 0.92 Mbp with a genomic GC content of 29.4% and contains 30 tRNAs. The genome is of high quality, consisting of 3 contigs, with a completeness of 96.4%, 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 highly abundant in oligotrophic lakes in temperate and subtropical regions. 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 92.57% and average nucleotide identity of 90.07% and another newly proposed species, Fontibacterium medardicus ME-17 (GCA_965235075.1), with an AAI of 85.45% and an ANI of 88.16%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__Fonsibacter; s__Fonsibacter sp947497305.

Type genome is Fontibacterium scandinaviense AM1_bin-0028 (GCA_903869725.1), a metagenome-assembled genome (MAG) assembled from 0.5 m depth from Lake Alinen Mustajärvi, Finland (date: 2015-08-8). AM1_bin-0028 has a genome size of 1.1 Mbp with a genomic GC content of 28.9%, contains 3 rRNA genes and 31 tRNAs. The genome is of high quality, consisting of 55 contigs, with a completeness of 100%, contamination of 0% and strain heterogeneity of 0% as assessed with checkM. The metagenome was assembled with Megahit (version 1.1.13) from short-read sequencing (Illumina MiSeq). Metagenomic fragment recruitment of >600 samples from five continents indicate that the species is mainly present in boreal lakes in Scandinavia. 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 72.71 % and average nucleotide identity of 75.18 % and another newly proposed species, Fontibacterium abundans MiE-29 (GCA_965235095.1), with an AAI of 73.3 % and an ANI of 75.56 %. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__Fonsibacter; s__Fonsibacter sp903869725.

Type genome is Fontibacterium subtropicum N-SamH-20apr23-026 (GCA_965235415.1), a metagenome-assembled genome (MAG) assembled from 15 m depth from Lake Samsonvale, Australia (date: 2023-04-20). N-SamH-20apr23-026 has a genome size of 1.15 Mbp with a genomic GC content of 29.3%, contains 3 rRNA genes and 34 tRNAs. The genome is of high quality, consisting of 100 contigs, with a completeness of 100%, contamination of 1.2% and strain heterogeneity of 100% 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 mainly in subtropical lakes. 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 88.13% and average nucleotide identity of 85.63% and another newly proposed species, Fontibacterium medardicus ME-17 (GCA_965235075.1), with an AAI of 90.92% and an ANI of 88.79%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__Fonsibacter; s__Fonsibacter sp023257975.

Type genome is Fontibacterium temperatum ZE-03apr19-LR-3 (GCA_964203055.1), a metagenome-assembled genome (MAG) assembled from 5 m depth from Lake Zurich, Switzerland (date: 2019-04-03). ZE-03apr19-LR-3 has a genome size of 0.9 Mbp with a genomic GC content of 29.4% and contains 28 tRNAs. The genome is of high quality, consisting of 3 contigs, with a completeness of 94%, 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 highly abundant in temperate lakes of the Northern Hemisphere. 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 87.44% and average nucleotide identity of 85.23% and another newly proposed species, Fontibacterium abundans MiE-29 (GCA_965235095.1), with an AAI of 93.82% and an ANI of 92.5%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__Fonsibacter; s__Fonsibacter sp000510845.

Type genome is Fontibacterium universale N-InaE-25sep22-010 (GCA_965236175.1), a metagenome-assembled genome (MAG) assembled from 5 m depth from Lake Inawashiro, Japan (date: 2022-09-25). N-InaE-25sep22-010 has a genome size of 1.0 Mbp with a genomic GC content of 29.3% and contains 29 tRNAs. The genome is of high quality, consisting of 4 contigs, with a completeness of 98.8%, 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 in many lakes around the world. 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 87.08% and average nucleotide identity of 85.18% and another newly proposed species, Fontibacterium abundans MiE-29 (GCA_965235095.1), with an AAI of 92.44% and an ANI of 90.87%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__Fonsibacter; s__Fonsibacter sp000371845.

Type genome is Pelagibacter malawiensis N-Mw13-23nov23-053 (GCA_965235955.1), a metagenome-assembled genome (MAG) assembled from 5 m depth from Lake Malawi, Malawi (date: 2023-11-23). N-Mw13-23nov23-053 has a genome size of 1 Mbp with a genomic GC content of 29.4%, contains 3 rRNA genes and 28 tRNAs. The genome is of high quality, consisting of 7 contigs, with a completeness of 99.5%, contamination of 0.5% 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). The closest cultivated relatives are ‘Candidatus Pelagibacter ubique SAR11 HTCC9022 (GCF_000472565.1), with an average amino acid identity of 75% and average nucleotide identity of 76.4% and ‘Candidatus Pelagibacter ubique SAR11 HTCC7211 (GCF_000155895.1), with an AAI of 74.2% and an ANI of 76.4%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__Pelagibacter; s__Pelagibacter sp016870175.

Type genome is Pelagilacustribacter hypolimneticus TrH-25oct19-165 (GCA_965235125.1), a metagenome-assembled genome (MAG) assembled from 150 m depth from Traunsee, Austria (date: 2019-10-25). TrH-25oct19-165 has a genome size of 1 Mbp with a genomic GC content of 29.2% and contains 19 tRNAs. The genome is of high quality, consisting of 87 contigs, with a completeness of 93.4%, contamination of 4.8% and strain heterogeneity of 20% as assessed with checkM. The metagenome was assembled with megahit from short-read sequencing (Illumina NovaSeq). The closest cultivated relative is Cosmipelagibacter malulaniensis HIMB058 (GCA_000419545.1), with an average amino acid identity of 58.8% and average nucleotide identity of 68.1%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Alphaproteobacteria; o__Pelagibacterales; f__Pelagibacteraceae; g__SYDM01; s__SYDM01 sp005801485.