Register list for 12 new names including Hahnella lacustris sp. nov.

Genus of Fimbriimonadaceae that is commonly found in freshwater environments. Type species is Fimbriicoccus planktonicus MsE-15 (GCA_965234685.1). The closest cultivated relative is Fimbriimonas ginsengisoli Gsoil 348 (GCF_000724625.1), with an average amino acid identity of 55.26% and an average nucleotide identity of 66.05%. Current GTDB classification (R220): d__Bacteria; p__Armatimonadota; c__Fimbriimonadia; o__Fimbriimonadales; f__Fimbriimonadaceae; g__Fimbriimonas. 

Description: A genus of abundant freshwater bacteria, commonly known from metagenomic and 16S rRNA amplicon studies, often referred to MWH-UniP1 group or betaVI in 16S rRNA based studies (PMCID:  PMC3063352, 31919153). It contains two species: Hahnella aquatica (MiE-11, GCA_965194505.1) and Hahnella lacustris (MsE-M47, GCA_965194655.1), both isolated from freshwater lakes. Type species is Hahnella aquatica MiE-11 (GCA_965194505.1). The closest cultivated relative is the undescribed Burkholderiales bacterium LSUCC0115 (GCA_009646425.1), with an average amino acid identity of 67-67.3% and average nucleotide identity of 70.6-71.7%. The closest validly described relative is Limnobacter thiooxidans CS-K2 (GCF_036323495.1), with AAIs of 53.6-54.4% and ANIs of 66.4-66.9%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Gammaproteobacteria; o__Burkholderiales; f__Burkholderiaceae_A; g__UBA2463.

The genus contains three species, Pernthalerella aquatica (GCA_965194445.1), Pernthalerella lacuna (GCA_965194545.1), and Pernthalerella communis (GCA_965194595.1) that were isolated from freshwater lakes. Type species is Pernthalerella aquatica GE-M3 (GCA_965194445.1). The closest cultivated relative is Paucimonas lemoignei DSM 7445 (GCF_004342585.1) with average amino acid identities of 64-64.5% and average nucleotide identities of 69.1-71%. SILVA classification of 16S rRNA genes is Bacteria/Proteobacteria/Gammaproteobacteria/Burkholderiales/Oxalobacteraceae/Noviherbaspirillum_3. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Gammaproteobacteria; o__Burkholderiales; f__Burkholderiaceae; g__SYFN01. 

Type species is Fimbriicoccus planktonicus MsE-15 (GCA_965234685.1), isolated from 5 m depth from Lake Most, Czechia (date: 2019-07-30), via high-throughput dilution to extinction cultivation. MsE-15 has a genome size of 3.29 Mbp with a genomic GC content of 56.5 %, contains 3 rRNA genes and 48 tRNAs. The genome is complete, consisting of a circular chromosome. No genes for flagella assembly and chemotaxis were annotated. Pathways for the biosynthesis of all amino acids except for alanine, proline, and histidine were predicted. Further, pathways for riboflavin, pyridoxal, NAD, coenzyme A, THF, and menaquinone biosynthesis were identified. The closest cultivated relative is Fimbriimonas ginsengisoli Gsoil 348 (GCF_000724625.1) with an average amino acid identity of 55.26% and an average nucleotide identity of 66.05%. Current GTDB classification (R220): d__Bacteria; p__Armatimonadota; c__Fimbriimonadia; o__Fimbriimonadales; f__Fimbriimonadaceae; g__Fimbriimonas; s__Fimbriimonas sp945882415.

Type species is Hahnella aquatica MiE-11 (GCA_965194505.1), isolated from 5 m depth from Lake Milada, Czechia (date: 2019-07-23), via high-throughput dilution to extinction cultivation. MiE-11 has a genome size of 1.8 Mbp with a genomic GC content of 61.8%, contains 3 rRNA genes and 43 tRNAs. The genome is complete, consisting of a circular chromosome. The genome contains genes encoding anoxygenic aerobic phototrophy (pufABLM). Genes for flagellar assembly were annotated. Pathways for thiosulfate oxidation (Sox pathway), glycolate oxidation, and the biosynthesis of all amino acids were predicted. Further, pathways for thiamine, riboflavin, NAD, pantothenate, coenzyme A, THF, and heme biosynthesis were identified. The closest cultivated relatives are the undescribed Burkholderiales bacterium LSUCC0115 (GCA_009646425.1), with an average amino acid identity of 67.3% and average nucleotide identity of 71.7% and another newly proposed species, Hahnella lacustris MsE-M47 (GCA_965194655.1), with an AAI of 65.8% and an ANI of 70.4%. The closest validly described relative is Limnobacter thiooxidans CS-K2 (GCF_036323495.1) with an AAI of 54.41% and an ANI of 66.9%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Gammaproteobacteria; o__Burkholderiales; f__Burkholderiaceae_A; g__UBA2463; s__. 

Type species is Hahnella lacustris MsE-M47 (GCA_965194655.1), isolated from 5 m depth from Lake Most, Czechia (date: 2019-10-01), via high-throughput dilution to extinction cultivation. MsE-M47 has a genome size of 2.2 Mbp with a genomic GC content of 59.2%, contains 3 rRNA genes and 42 tRNAs. The genome is complete, consisting of a circular chromosome. The genome is complete, consisting of a circular chromosome. The genome contains genes encoding anoxygenic aerobic phototrophy (pufABLM) and the complete Calvin cycle for carbon fixation via RuBisCO. Genes for flagellar assembly and chemotaxis were annotated. Pathways for taurine degradation, thiosulfate oxidation (Sox pathway), glycolate oxidation, and the biosynthesis of all amino acids were predicted. Further, pathways for riboflavin, NAD, pantothenate, coenzyme A, biotin, THF, and heme biosynthesis were identified. The closest cultivated relative is the undescribed Burkholderiales bacterium LSUCC0115 (GCA_009646425.1), with an average amino acid identity of 67% and average nucleotide identity of 70.6% and another newly proposed species, Hahnella aquatica MiE-11 (GCA_965194505.1), with an AAI of 65.8% and an ANI of 70.4%. The closest validly described relative is Limnobacter thiooxidans CS-K2 (GCF_036323495.1) with an AAI of 53.55% and an ANI of 66.44%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Gammaproteobacteria; o__Burkholderiales; f__Burkholderiaceae_A; g__UBA2463; s__UBA2463 sp945862985.

Type strain is Limnohabitans simekii MiE-M12 (GCA_965234735.1), isolated from 5 m depth from Lake Milada, Czechia (date: 2019-04-16), via high-throughput dilution to extinction cultivation. MiE-M12 has a genome size of 2.7 Mbp with a genomic GC content of 55.8 %, contains 3 rRNA genes and 37 tRNAs. The genome is a high-quality draft consisting of 9 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, thiosulfate oxidation (Sox pathway), glycolate oxidation, and the biosynthesis of all amino acids were predicted. Further, pathways for thiamine, riboflavin, coenzyme A, biotin, THF, and heme biosynthesis were identified. The closest cultivated relative is Limnohabitans sp. Jir61 (GCF_003063545.1) with an average amino acid identity of 66.2% and average nucleotide identity of 72.6%. Current GTDB classification (R220): d__Bacteria; p__Pseudomonadota; c__Gammaproteobacteria; o__Burkholderiales; f__Burkholderiaceae_B; g__Limnohabitans; s__Limnohabitans sp937891045.

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__. 

Type species is Pernthalerella communis MsE-6 (GCA_965194595.1), isolated from 5 m depth from Lake Most, Czechia (date: 2019-04-30), via high-throughput dilution to extinction cultivation. MsE-6 has a genome size of 3 Mbp with a genomic GC content of 47.7%, contains 3 rRNA genes and 37 tRNAs. The genome is a high-quality draft consisting of 27 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 salicylate 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 64.02% and average nucleotide identity of 69.11% and two other newly proposed species, Pernthalerella lacuna MaE-M21 (GCA_965194545.1) and Pernthalerella aquatica GE-M3 (GCA_965194445.1), 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__SYFN01 sp903846425.

Type species is Pernthalerella lacuna MaE-M21 (GCA_965194545.1), isolated from 5 m depth from Lake Maggiore, Italy (date: 2019-11-04), via high-throughput dilution to extinction cultivation. MaE-M21 has a genome size of 2.8 Mbp with a genomic GC content of 54.9%, contains 3 rRNA genes and 45 tRNAs. The genome is a high-quality draft consisting of 7 contigs. The genome contains genes encoding anoxygenic aerobic phototrophy (pufABLM). Genes for flagellar and pilus assembly were annotated. Pathways for benzene 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 64.16% and average nucleotide identity of 70.49% and two other newly proposed species, Pernthalerella aquatica GE-M3 (GCA_965194445.1 ) 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__SYFN01 sp021299035.

Type species is Planktophila grossartii RE-3 (GCA_965234365.1), isolated from 0.5 m depth from the Římov reservoir, Czechia (date: 2019-04-23), via high-throughput dilution to extinction cultivation. RE-3 has a genome size of 1.4 Mbp with a genomic GC content of 48.8 %, contains 3 rRNA genes and 38 tRNAs. The genome is complete, consisting of a circular chromosome. The genome contains genes encoding rhodopsins. No genes for flagella or pilus assembly and chemotaxis were annotated. Pathways for taurine degradation and the biosynthesis of all amino acids except for histidine were predicted. Further, pathways for riboflavin, pyridoxal, coenzyme A, NAD, and menaquinone biosynthesis were identified. The closest cultivated relative is Actinobacteria bacterium IMCC25003 (GCA_002284855.1) with an average nucleotide identity of 90.33%. Current GTDB classification (R220): d__Bacteria; p__Actinomycetota; c__Actinomycetia; o__Nanopelagicales; f__Nanopelagicaceae; g__Planktophila; s__Planktophila sp009701085. 

Type species is Planktophila turicensis ZE-9 (GCA_965234405.1), isolated from 5 m depth from Lake Zurich, Switzerland (date: 2019-11-13), via high-throughput dilution to extinction cultivation. ZE-9 has a genome size of 1.4 Mbp with a genomic GC content of 48.5%, contains 3 rRNA genes and 39 tRNAs. The genome is complete, consisting of a circular chromosome. The genome contains genes encoding rhodopsins. No genes for flagella or pilus assembly and chemotaxis were annotated. Pathways for taurine degradation and the biosynthesis of all amino acids except for histidine were predicted. Further, pathways for riboflavin, pyridoxal, coenzyme A, NAD, and menaquinone biosynthesis were identified. The closest cultivated relative is ‘Candidatus Planktophila sulfonica’ MMS-IA-56 (GCF_002288185.1), with an average nucleotide identity of 94.22%. Current GTDB classification (R220): d__Bacteria; p__Actinomycetota; c__Actinomycetia; o__Nanopelagicales; f__Nanopelagicaceae; g__Planktophila; s__.