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Three Gram-stain-negative, aerobic, short rod-shaped and motile strains (FXH3W T , SHGZ20W and SMYT11W T ) were isolated from freshwater environments in China. Comparisons based on the 16S rRNA gene sequences indicated that strains FXH3W T and SHGZ20W showed the highest 16S rRNA gene sequence similarity of about 99.6% to ' Luteimonas cellulosilyticus ' MIC 1.5, and strain SMYT11W T showed the highest 16S rRNA gene sequence similarity of 99.8% to Luteimonas fraxinea D4P002 T , respectively. Observing the phylogenetic trees reconstructed based on the 16S rRNA gene sequences, the species of genera Luteimonas and Lysobacter were not monophyletic and often mixed together. The further reconstructed phylogenomic tree and Genome Taxonomy Database also showed that the species of both genera were polyphyletic, implying that the current taxonomic status of the species of both genera was questionable. The calculated OrthoANIu, digital DNA-DNA hybridization and average amino acid sequence identity (AAI) values supported that strains FXH3W T and SHGZ20W should belong to the same novel species and strain SMYT11W T should also represent an independent novel species. Combining the AAI values and phylogenomic analyses, the species of genera Luteimonas and Lysobacter should be reassigned to 12 genera ( Luteimonas , Lysobacter , Cognatiluteimonas , Noviluteimonas , Pseudoluteimonas , Solilutibacter , Agrilutibacter , Cognatilysobacter , Marilutibacter , Novilysobacter , Montanilutibacter and Aerolutibacter ). The AAI values 69.5-76.0% were also proposed as the Lysobacteraceae -specific thresholds for genus delineation. Strain SMYT11W T should represent a novel species of the genus Luteimonas , for which the name Luteimonas flava sp. nov. (type strains SMYT11W T =GDMCC 1.4275 T =KCTC 8304 T ) is proposed. Strains FXH3W T and SHGZ20W should represent a novel species of a new genus Aquilutibacter rugosus gen. nov., sp. nov. The type strain of the type species is FXH3W T (=GDMCC 1.4096 T =KCTC 8154 T ).

A polyphasic taxonomic study was carried out on strains CHu50b-3-2 T and CHu40b-3-1 isolated from a 67 cm-long sediment core collected from the Daechung Reservoir at a water depth of 17 m, Daejeon, Republic of Korea. The cells of the strains were Gram-stain-negative, non-spore-forming, non-motile and rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of two strains with γ-Proteobacteria , which showed the highest pairwise sequence similarities to Lysobacter hankyongensis KTce-2 T (96.5 %), Lysobacter pocheonensis Gsoil193 T (96.3 %), Lysobacter ginsengisoli Gsoil 357 T (96.1 %), Lysobacter solanacearum T20R-70 T (96.1 %), Lysobacter brunescens KCTC 12130 T (95.4 %) and Lysobacter capsici YC5194 T (95.3 %). The phylogenetic analysis based on 16S rRNA gene sequences showed that the strains formed a clear phylogenetic lineage with the genus Lysobacter . The major fatty acids were identified as summed feature 9 (iso-C 17 : 1  ω 9 c and/or C 18 : 1 10-methyl), iso-C 15 : 0 , iso-C 16 : 0 and iso-C 17 : 0 . The respiratory quinone was identified as ubiquinone Q-8. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The genomic DNA G+C content was determined to be 66.8 mol% (genome) for strain CHu50b-3-2 T and 66.4 mol% (HPLC) for strain CHu40b-3-1. Based on the combined genotypic and phenotypic data, we propose that strains CHu50b-3-2 T and CHu40b-3-1 represent a novel species of the genus Lysobacter , for which the name Lysobacter profundi sp. nov. is proposed. The type strain is CHu50b-3-2 T (=KCTC 72973 T =CCTCC AB 2019129 T ). Besides Lysobacter panaciterrae Gsoil 068 T formed a phylogenetic group together with strain Luteimonas aquatica RIB1-20 T (EF626688) that is clearly separated from all other known Lysobacter strains. Based on the phylogenetic relationships together with fatty acid compositions, Lysobacter panaciterrae Gsoil 068 T should be reclassified as a member of the genus Luteimonas: Luteimonas aquatica comb. nov. (type strain Gsoil 068 T =KCTC 12601 T =DSM 17927 T ).

A Gram-negative, aerobic, rod shaped, non-spore-forming bacterial strain, designated Dae08(T), was isolated from sediment of the stream near Daechung dam in South Korea, and was characterized in order to determine its taxonomic position, using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain Dae08(T) belongs to the family Xanthomonadaceae of the Gammaproteobacteria, and is related to Lysobacter brunescens ATCC 29482(T) (97.3%). The phylogenetic distances from any other species with validly published names within the genus Lysobacter were greater than 3.7%. The G+C contents of the genomic DNA of strain Dae08(T) was 69.3 mol%. The detection of a quinone system with Q-8 as the predominant compound and a fatty acid profile with iso-C(15:0), iso-C(17:1), omega9c, iso-C(17:0), iso-C(16:0), and iso-C(11:0) 3-OH as the major acids supported the affiliation of strain Dae08(T) to the genus Lysobacter. DNA-DNA relatedness between strain Dae08(T) and its phylogenetically closest neighbour was 28%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Dae08(T) (= KCTC 12600(T)) should be classified in the genus Lysobacter as the novel species, for which the name Lysobacter daecheongensis sp. nov. is proposed.