Non-motile Strain Research Articles

Hohaiivirga grylli gen. nov., sp. nov., a New Member of the Family Methylobacteriaceae, Isolated from Cricket (Gryllus chinensis).

A Gram-staining negative, non-motile, rod-shaped, oxidase negative and catalase positive strain WL0021T was isolated from cricket (Gryllus chinensis) living in the campus of Hohai University. Strain WL0021T was characterized utilizing a polyphasic taxonomy approach. The major fatty acids (> 5%) for strain WL0021T were C16:0 and summed feature 8, and the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phospholipid, two aminolipids, and an unidentified polar lipid. Ubiquinone-10 was detected as the predominant respiratory quinone. The results of 16S rRNA gene phylogenetic analyses revealed that strain WL0021T had the highest sequence similarity of 95.3% to Microvirga flavescens c27j1T and strain WL0021T formed a distinct linage within the family Methylobacteriaceae in the phylogenetic trees. Whole genomic DNA G+C content was 48.3%. Combined with the results from this study, strain WL0021T should represent a novel genus in the family Methylobacteriaceae, for which the name Hohaiivirga grylli gen. nov., sp. nov. (type strain WL0021T=GDMCC 1.2420T =JCM 34655T=MCCC 1K05886T) is proposed.

Acidisoma cladoniae sp. nov., an acidotolerant bacterium isolated from an Antarctic lichen.

Gram-staining-negative, aerobic, white-cream-pearly colony, coccobacilli, and non-motile bacterial strain, PAMC 29798T was isolated from an Antarctic lichen. The strain was acidotolerant and psychrotolerant growing at pH 4.0-7.5 (optimally at pH 4.0-6.5) and 0-25°C (optimally at 10-20°C). The major fatty acids are Summed Feature 8, C18:1 2OH, and C19:0 cyclo ω8c. The major respiratory quinone was Q-10. Phylogenetic and phylogenomic analyses indicated that strain PAMC 29798T belonged to the genus Acidisoma and 16S rRNA gene sequences of PAMC 29798T were closely related to Acidisoma silvae (97.7% sequence similarity), Acidisoma cellulosilyticum (96.5%), Acidisoma tundrae (96.5%), and Acidisoma sibiricum (96.3%). Genomic relatedness analyses showed that strain PAMC 29798T was clearly distinguished from type strains of the genus Acidisoma based on values of average nucleotide identity (< 75%) and the digital DNA-DNA hybridization (< 19.6%). Genome analysis revealed that the genome size of PAMC 29798T is approximately 5.0 Mb with a G+C content of 63.4%. The complete genome comprises 5 contigs containing 4636 protein-coding genes, 46 tRNA genes, and 2 rRNA operons. The genome possesses genes for light-harvesting complexes, type-II photosynthetic reaction center, and C-P lyase to solubilize organic phosphates, while genes encoding nitrogenase iron protein involved in the nitrogen fixation were not present. Based on the results of phylogenetic, genome-based relatedness, and physiological and genomic analyses, strain PAMC 29798T is proposed to represent a novel species of the genus Acidisoma, with the name Acidisoma cladoniae. The type strain is PAMC 29798T (= KCTC 82159T = JCM 35634T).

Paralimibaculum aggregatum gen. nov. sp. nov. and Biformimicrobium ophioploci gen. nov. sp. nov., two novel heterotrophs from brittle star Ophioplocus japonicus.

Two novel Gram-stain-negative, strictly aerobic, halophilic and non-motile bacterial strains, designated NKW23T and NKW57T, were isolated from a brittle star Ophioplocus japonicus collected from a tidal pool in Wakayama, Japan. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that NKW23T represented a member of the family Paracoccaceae, with Limibaculum halophilum CAU 1123T as its closest relative (94.4% sequence identity). NKW57T was identified as representing a member of the family Microbulbiferaceae, with up to 94.9% sequence identity with its closest relatives. Both strains displayed average nucleotide identity (ANI) and digital DNA-DNA hybridisation (dDDH) values below the species delimitation threshold against their closest relatives. Additionally, amino acid identity (AAI) values of both strains fell below the genus-defining threshold. Phylogenetic trees based on genome sequences indicated that NKW23T formed a novel lineage, branching deeply prior to the divergence of the genera Limibaculum and Thermohalobaculum, with an evolutionary distance (ED) of 0.31-0.32, indicative of genus-level differentiation. NKW57T similarly formed a distinct lineage separate from the species of the genus Microbulbifer. The major respiratory quinones of NKW23T and NKW57T were ubiquinone-10 (Q-10) and Q-8, respectively. The genomic DNA G+C contents of NKW23T and NKW57T were 71.4 and 58.8%, respectively. On the basis of the physiological and phylogenetic characteristics, it was proposed that these strains should be classified as novel species representing two novel genera: Paralimibaculum aggregatum gen. nov., sp. nov., with strain NKW23T (=JCM 36220T=KCTC 8062T) as the type strain, and Biformimicrobium ophioploci gen. nov., sp. nov., with strain NKW57T (=JCM 36221T=KCTC 8063T) as the type strain.

Vagococcus jeotgali sp. nov., isolated from cutlassfish jeotgal, a traditional Korean fermented seafood.

A novel, Gram-positive, facultatively anaerobic, and non-motile bacterial strain, designated B2T-5T, was isolated from jeotgal, a traditional Korean fermented seafood. Colonies grown on gifu anaerobic medium agar plates were cream-coloured, irregular, and umbonate with curled margins. Optimal growth of strain B2T-5T occurred at 20 °C, pH 8.0, and in the presence of 1% (w/v) NaCl. Strain B2T-5T was negative for oxidase and catalase activity. Hippurate was not hydrolysed and acetoin was not produced. The major cellular fatty acids were C18 : 1 ω9c and C16 : 0. The cell-wall peptidoglycan was of the A4α type containing l-Lys-d-Asp. The predominant respiratory quinone was menaquinone 7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylcholine. According to the phylogenetic analysis based on 16S rRNA gene sequences, strain B2T-5T was most closely related to Vagococcus teuberi DSM 21459T, showing 98.2% sequence similarity. Genome sequencing of strain B2T-5T revealed a genome size of 2.0 Mbp and a G+C content of 33.8 mol%. The average nucleotide identities of strain B2T-5T with Vagococcus teuberi DSM 21459T, Vagococcus bubulae SS1994T, and Vagococcus martis D7T301T were 75.0, 74.7, and 75.1%, respectively. Based on the phenotypic, chemotaxonomic, and genotypic data, strain B2T-5T represents a novel species of the genus Vagococcus, for which the name Vagococcus jeotgali sp. nov. is proposed. The type strain is B2T-5T (=KCTC 21223T=JCM 35937T).

Chengkuizengella axinellae sp. nov., a symbiotic bacterium isolated from a marine sponge of the genus Axinella.

A Gram-stain-positive, strictly aerobic, creamy-white colored, endospore-forming and non-motile rods strain, designated as strain 2205SS18-9T, was isolated from a marine sponge, Axinella sp. collected from Seopseom Island, Republic of Korea. Optimal growth of strain 2205SS18-9T was observed at 25-30°C, pH 6.5-7.0, and in the presence of 3.0% (w/v) NaCl. Cells were oxidase-positive and catalase-negative. Negative for nitrate reduction and indole production. Phylogenetic analyses based on the 16S rRNA gene and whole-genome sequences revealed that strain 2205SS18-9T formed a distinct phyletic lineage in the genus Chengkuizengella, and it was most closely related to Chengkuizengella marina YPA3-1-1T and Chengkuizengella sediminis J15A17T with 97.1 and 96.6% 16S rRNA gene sequence similarities, respectively. The average nucleotide identity and digital DNA-DNA hybridization values between strain 2205SS18-9T and Chengkuizengella marina YPA3-1-1T were 79.0 and 21.6%, respectively. The genomic DNA G + C content was 34.1%. The genome harbors a number of host-adhesion and transporter genes, suggested that strain 2205SS18-9T may interact with its sponge host as a symbiont. Menaquinone-7 was the sole isoprenoid quinone and antieiso-C15:0 (28.5%), iso-C16:0 (25.8%), C16:1 ω7c alcohol (15.0%), and iso-C15:0 (11.2%) were detected as the major fatty acids. Polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified aminophospholipids, and an unidentified lipid. The cell-wall peptidoglycan contained lysine, alanine, glutamate, and aspartate. Based on these analyses, strain 2205SS18-9T represents a novel species of the genus Chengkuizengella, for which the name Chengkuizengella axinellae sp. nov. is proposed. The type strain is 2205SS18-9T (= KACC 23238T = LMG 33063T).

Thalassospira aquimaris sp. nov. and Winogradskyella marincola sp. nov. two marine bacteria isolated from an agar-degrading co-culture.

Two novel Gram-stain-negative, aerobic, and non-motile strains, designated FZY0004T and YYF002T, were isolated from an agar-degrading co-culture, which was obtained from seawater of the intertidal zone of Yancheng City, the Yellow Sea of China. Strain FZY0004T optimally grew at 28°C, pH 7.0, and 2-6% NaCl, while strain YYF002T optimally grew at 28°C, pH 7.5, and 2-4% NaCl. Strain FZY0004T possessed Q-9 as the major respiratory quinone, and its major fatty acids (> 10%) were summed feature 8 (C18:1 ω7c), C16:0, and summed feature 3 (C16:1 ω7c/C16:1 ω6c). The polar lipids identified in strain FZY0004T were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and several unidentified phospholipids (PL) and lipids (L). On the other hand, strain YYF002T had MK-6 as the predominant respiratory quinone and its major fatty acids consisted of iso-C15:0, iso-C15:1 G, and iso-C15:0 3-OH. The polar lipids identified in strain YYF002T were aminolipid (AL), PE, and several unidentified lipids. Strain FZY0004T shared 99.5% 16S rRNA gene sequence similarity and 90.1% average nucleotide identity (ANI) with T. povalilytica Zumi 95T, and strain YYF002T shared 99.2% 16S rRNA gene sequence similarity and 88.2% ANI with W. poriferorum JCM 12885T. The genomic DNA G + C contents of strains FZY0004T and YYF002T were 54.5% and 33.5%, respectively. The phylogenetic, phenotypic, and physiological characteristics permitted the distinction of the two strains from their neighbors, and we thus propose the names Thalassospira aquimaris sp. nov. (type strain FZY0004T = JCM 35895T = MCCC 1K08380T) and Winogradskyella marincola sp. nov. (type strain YYF002T = JCM 35950T = MCCC 1K08382T).

Functional Analysis of the Major Pilin Proteins of Type IV Pili in Streptococcus sanguinis CGMH010.

The pil gene cluster for Type IV pilus (Tfp) biosynthesis is commonly present and highly conserved in Streptococcus sanguinis. Nevertheless, Tfp-mediated twitching motility is less common among strains, and the factors determining twitching activity are not fully understood. Here, we analyzed the functions of three major pilin proteins (PilA1, PilA2, and PilA3) in the assembly and activity of Tfp in motile S. sanguinis CGMH010. Using various recombinant pilA deletion strains, we found that Tfp composed of different PilA proteins varied morphologically and functionally. Among the three PilA proteins, PilA1 was most critical in the assembly of twitching-active Tfp, and recombinant strains expressing motility generated more structured biofilms under constant shearing forces compared to the non-motile recombinant strains. Although PilA1 and PilA3 shared 94% identity, PilA3 could not compensate for the loss of PilA1, suggesting that the nature of PilA proteins plays an essential role in twitching activity. The single deletion of individual pilA genes had little effect on the invasion of host endothelia by S. sanguinis CGMH010. In contrast, the deletion of all three pilA genes or pilT, encoding the retraction ATPase, abolished Tfp-mediated invasion. Tfp- and PilT-dependent invasion were also detected in the non-motile S. sanguinis SK36, and thus, the retraction of Tfp, but not active twitching, was found to be essential for invasion.

Qipengyuania benthica sp. nov. and Qipengyuania profundimaris sp. nov., two novel Erythrobacteraceae members isolated from deep-sea environments.

Two Gram-stain-negative, rod-shaped and non-motile strains, designated as DY56-A-20T and G39T, were isolated from deep-sea sediment of the Pacific Ocean and deep-sea seawater of the Indian Ocean, respectively. Strain DY56-A-20T was found to grow at 15-37 °C (optimum, 28 °C), at pH 6.0-10.0 (optimum, pH 6.5-7.0) and in 0.5-6.0 % (w/v) NaCl (optimum, 1.0-2.0 %), while strain G39T was found to grow at 10-42 °C (optimum, 35-40 °C), at pH 5.5-10.0 (optimum, pH 6.5-7.0) and in 0-12.0 % (w/v) NaCl (optimum, 1.0-2.0 %). The 16S rRNA gene sequence identity analysis indicated that strain DY56-A-20T had the highest sequence identity with Qipengyuania marisflavi KEM-5T (97.6 %), while strain G39T displayed the highest sequence identity with Qipengyuania citrea H150T (98.8 %). The phylogenomic reconstruction indicated that both strains formed independent clades within the genus Qipengyuania. The digital DNA-DNA hybridization and average nucleotide identity values between strains DY56-A-20T/G39T and Qipengyuania/Erythrobacter type strains were 17.8-23.8 % and 70.7-81.1 %, respectively, which are below species delineation thresholds. The genome DNA G+C contents were 65.0 and 63.5 mol% for strains DY56-A-20T and G39T, respectively. The predominant cellular fatty acids (>10 %) of strain DY56-A-20T were C17 : 1 ω6c, summed feature 8 and summed feature 3, and the major cellular fatty acids of strain G39T were C17 : 1 ω6c and summed feature 8. The major polar lipids in both strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid and an unidentified polar lipid. The only respiratory quinone present in both strains was ubiquinone-10. Based on those genotypic and phenotypic results, the two strains represent two novel species belonging to the genus Qipengyuania, for which the names Qipengyuania benthica sp. nov. and Qipengyuania profundimaris sp. nov. are proposed. The type strain of Q. benthica is DY56-A-20T (=MCCC M27941T=KCTC 92309T), and the type strain of Q. profundimaris is G39T (=MCCC M30353T=KCTC 8208T).

Arcicella gelida sp. nov. and Arcicella lustrica sp. nov., isolated from streams in China and re-examining the taxonomic status of all the genera within the families Spirosomataceae and Cytophagaceae.

Three Gram-stain-negative, aerobic, rod-shaped, non-motile strains (DC2WT, DC25WT, and LKC2W) were isolated from streams in China. Comparisons based on the 16S rRNA gene sequences showed that these three strains share 16S rRNA gene sequence similarity values over 97.0 % with the species of genus Arcicella. There was confusion due to the fact that all species of genera Flectobacillus, Aquirufa, and Sandaracinomonas show 16S rRNA gene sequence similarity of over 90.0 % to the above three strains, but the genus Flectobacillus belongs to the family Spirosomataceae and the genera Aquirufa and Sandaracinomonas belong to the family Cytophagaceae. Observing the phylogenetic trees, strains DC2WT, DC25WT, and LKC2W cluster closely with the species of genus Arcicella, but some species within the families Spirosomataceae and Cytophagaceae are not monophyletic. The phylogenomic tree also showed a confused phylogenetic relationships among these non-monophyletic species. Combining the phylogenetic relationships and average nucleotide identity values, the current taxonomic status of all the genera within the families Spirosomataceae and Cytophagaceae were re-examined. The genera 'Chryseosolibacter', 'Dawidia', and Chryseotalea should belong to the new family Chryseotaleaceae fam. nov., the genera Arcicella, Flectobacillus, Pseudarcicella, Aquirufa, and Sandaracinomonas should belong to the new family Flectobacillaceae fam. nov., the genera Fluviimonas, Taeseokella, Arcticibacterium, Emticicia, Jiulongibacter, Marinilongibacter, Lacihabitans, and Leadbetterella should belong to the new family Leadbetterellaceae fam. nov., the genus Litoribacter should be reassigned to the family Cyclobacteriaceae, and the genera Arundinibacter and Tellurirhabdus should be reassigned to the family Spirosomataceae. Strains DC2WT and DC25WT are reported to represent two novel species of the genus Arcicella, for which the names Arcicella gelida sp. nov. (type strain DC2WT=GDMCC 1.3209T=KCTC 92559T) and Arcicella lustrica sp. nov. (type strain DC25WT=GDMCC 1.3210T=KCTC 92557T) are proposed.

Phocaeicola acetigenes sp. nov., producing acetic acid and iso-butyric acid, isolated faeces from a healthy human.

An obligately anaerobic, non-motile, Gram-stain-negative, and rod-shaped strain KGMB11183T was isolated from the feces of healthy Koreans. The growth of strain KGMB11183T occurred at 30-45°C (optimum 37°C), at pH 6-9 (optimum pH 7), and in the presence of 0-0.5% NaCl (optimum 0%). Strain KGMB11183T showed 16S rRNA gene sequence similarities of 95.4% and 94.2% to the closest recognized species, Phocaeicola plebeius M12T, and Phocaeicola faecicola AGMB03916T. Phylogenetic analysis showed that strain KGMB11183T is a member of the genus Phocaeiocla. The major end products of fermentation are acetic acid and isobutyric acid. The major cellular fatty acids (> 10%) of this isolate were C18:1 cis 9, anteiso-C15:0, and summed feature 11 (iso-C17:0 3-OH and/or C18:2 DMA). The assembled draft genome sequences of strain KGMB11183T consisted of 3,215,271bp with a DNA G + C content of 41.4%. According to genomic analysis, strain KGMB11183T has a number of genes that produce acetic acid. The genome of strain KGMB11183T encoded the starch utilization system (Sus) operon, SusCDEF suggesting that strain uses many complex polysaccharides that cannot be digested by humans. Based on the physiological, chemotaxonomic, phenotypic, and phylogenetic data, strain KGMB11183T is regarded a novel species of the genus Phocaeicola. The type strain is KGMB11183T (= KCTC 25284T = JCM 35696T).

Mycolicibacterium arseniciresistens sp. nov., isolated from lead-zinc mine tailing, and reclassification of two Mycobacterium species as Mycolicibacterium palauense comb. nov. and Mycolicibacterium grossiae comb. nov.

A Gram-positive, acid-fast, aerobic, rapidly growing and non-motile strain was isolated from lead-zinc mine tailing sampled in Lanping, Yunnan province, Southwest China. 16S rRNA gene sequence analysis showed that the most closely related species of strain KC 300T was Mycolicibacterium litorale CGMCC 4.5724T (98.47 %). Additionally, phylogenomic and specific conserved signature indel analysis revealed that strain KC 300T should be a member of genus Mycolicibacterium, and Mycobacterium palauense CECT 8779T and Mycobacterium grossiae DSM 104744T should also members of genus Mycolicibacterium. The genome size of strain KC 300T was 6.2 Mb with an in silico DNA G+C content of 69.2 mol%. Chemotaxonomic characteristics of strain KC 300T were also consistent with the genus Mycolicibacterium. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values, as well as phenotypic, physiological and biochemical characteristics, support that strain KC 300T represents a new species within the genus Mycolicibacterium, for which the name Mycolicibacterium arseniciresistens sp. nov. is proposed, with the type strain KC 300T (=CGMCC 1.19494T=JCM 35915T). In addition, we reclassified Mycobacterium palauense and Mycobacterium grossiae as Mycolicibacterium palauense comb. nov. and Mycolicibacterium grossiae comb. nov., respectively.

A novel UV-resistant bacterium Sphingomonas endolithica sp. nov., and genomic analysis, isolated from the north slope of Mount Everest.

Gram-stain-negative, aerobic, rod-shaped, non-motile bacterium strain ZFBP2030T was isolated from a rock on the North slope of Mount Everest. This strain contained a unique ubiquinone-10 (Q-10) as a predominant respiratory quinone. Among the tested fatty acids, the strain contained summed feature 8, C14:0 2OH, and C16:0, as major cellular fatty acids. The polar lipid profile contained phosphatidyl glycerol, phosphatidyl ethanolamine, three unidentified phospholipids, two unidentified aminolipids, and six unidentified lipids. The cell-wall peptidoglycan was a meso-diaminopimelic acid, and cell-wall sugars were ribose and galactose. Phylogenetic analyses based on 16S rRNA gene sequence revealed that strain ZFBP2030T was a member of the genus Sphingomonas, exhibiting high sequence similarity to the 16S rRNA gene sequences of Sphingomonas aliaeris DH-S5T (97.9%), Sphingomonas alpina DSM 22537T (97.3%) and Sphingomonas hylomeconis CCTCC AB 2013304T (97.0%). The 16S rRNA gene sequence similarity between ZFBP2030T and other typical strains was less than 97.0%. The average amino acid identity values, average nucleotide identity, and digital DNA-DNA hybridization values between strain ZFBP2030T and its highest sequence similarity strains were 56.9-79.9%, 65.1-82.2%, and 19.3-25.8%, respectively. The whole-genome size of the novel strain ZFBP2030T was 4.1 Mbp, annotated with 3838 protein-coding genes and 54 RNA genes. Moreover, DNA G + C content was 64.7mol%. Stress-related functions predicted in the subsystem classification of the strain ZFBP2030T genome included osmotic, oxidative, cold/heat shock, detoxification, and periplasmic stress responses. The overall results of this study clearly showed that strain ZFBP2030T is a novel species of the genus Sphingomonas, for which the name Sphingomonas endolithica sp. nov. is proposed. The type of strain is ZFBP2030T (= EE 013T = GDMCC 1.3123T = JCM 35386T).

Muricauda myxillae sp. nov., isolated from a marine sponge (Myxilla rosacea), and reclassification of Flagellimonas hymeniacidonis as Muricauda symbiotica nom. nov.

A Gram-stain-negative, aerobic and non-motile rods strain, designated as strain 2012CJ39-3T, was isolated from a marine sponge, Myxilla rosacea, collected on Chuja Island, Republic of Korea. Optimal growth of strain 2012CJ39-3T was observed at 25 °C, pH 7.0 and in the presence of 2.0-3.0 % (w/v) NaCl. Strain 2012CJ39-3T contained menaquinone-6 as the respiratory quinone, iso-C15 : 1 G, iso-C15 : 0, and iso-C17 : 0 3-OH as the predominant fatty acids, and phosphatidylethanolamine, an unidentified phospholipid, an unidentified glycolipid, three unidentified aminolipids and nine unidentified lipids as major polar lipids. The genomic DNA G+C content was 38.4 mol%. Results of phylogenetic analyses based on the 16S rRNA gene and whole-genome sequences revealed that strain 2012CJ39-3T formed a distinct phyletic lineage in the genus Muricauda. Strain 2012CJ39-3T was most closely related to Flagellimonas hymeniacidonis 176CP5-101T, Muricauda spongiicola 2012CJ35-5T, Muricauda algicola AsT0115T, Muricauda flava DSM 22638T and Muricauda parva SW169T with 96.5, 96.4, 96.3, 95.8 and 95.6 % 16S rRNA gene sequence similarity, respectively. The average nucleotide identity and digital DNA-DNA hybridization values between strain 2012CJ39-3T and M. spongiicola 2012CJ35-5T, F. hymeniacidonis 176CP5-101T, M. algicola AsT0115T, M. flava DSM 22638T and M. parva SW169T were 75.6, 74.2, 78.6, 75.3 and 74.8 % and 27.4, 19.9, 36.3, 24.2 and 18.9 %, respectively. Based on these results, strain 2012CJ39-3T represents a novel species of the genus Muricauda, for which the name Muricauda myxillae sp. nov. is proposed. The type strain is 2012CJ39-3T (=KACC 22644T= LMG 32582T). In addition, Flagellimonas hymeniacidonis is reclassified as Muricauda symbiotica nom. nov.

Robiginitalea aurantiaca sp. nov. and Algoriphagus sediminis sp. nov., isolated from coastal sediment.

Two novel rod-shaped, Gram-stain-negative, aerobic and non-motile bacterial strains, designated M39T and C2-7T, were isolated from the coastal sediment of Xiaoshi Island, Weihai, PR China. Growth of strain M39T occurred at 15-37 °C, at pH 6.0-9.0 and in the presence of 1.0-9.0 % (w/v) NaCl. Strain C2-7T grew at 15-40 °C, at pH 6.0-8.0 and in the presence of 0.5-8.0 % (w/v) NaCl. Phylogenetic analysis based 16S rRNA gene sequences revealed that strains M39T and C2-7T belong to the phylum Bacteroidota. Based on the results of 16S rRNA gene sequence analysis, the closest relative of strain M39T was Robiginitalea marina KCTC 92035T (95.4 %), and the closest relative of strain C2-7T was Algoriphagus namhaensis DPG-3T (97.0 %). The percentage of conserved protein and average nucleotide identity values between strain M39T and some species of the genus Robiginitalea were 66.9-77.6% and 69.3-71.0 %, respectively, while those between strain C2-7T and some species of the genus Algoriphagus were 68.0-70.1% and 56.1-72.6 %, respectively. The major cellular fatty acids (>10 %) of strain M39T consisted of iso-C15 : 1 F, iso-C15 : 0 and iso-C17 : 0 3-OH, while those of strain C2-7T were iso-C15 : 0 and C16 : 1 ω7c/C16 : 1 ω6c. MK-6 was the only respiratory quinone that was compatible with the genus of strain M39T. The predominant menaquinone of strain C2-7T was MK-7. The major polar lipids of strain M39T were phosphatidylethanolamine and glycolipids, and those of strain C2-7T were phosphatidylethanolamine, one unidentified aminolipid and four unidentified lipids. The DNA G+C contents of strains M39T and C2-7T were 46.9 and 40.8 mol%, respectively. Based upon the results presented in this study, strains M39T and C2-7T represent novel species of the genera Robiginitalea and Algoriphagus, respectively, for which the names Robiginitalea aurantiaca sp. nov. and Algoriphagus sediminis sp. nov. are proposed with the type strains M39T (=MCCC 1H00498T=KCTC 92014T) and C2-7T (=MCCC 1H00414T=KCTC 92027T).

Flectobacillus longus sp. nov. and Flectobacillus rivi sp. nov., isolated from streams in China and reclassification of Flectobacillus rhizosphaerae as a synonym of Flectobacillus roseus.

Three Gram-stain-negative, aerobic, rod-shaped, non-motile strains (LYT7WT, DC10W and LFS242WT) were isolated from streams in PR China. Comparisons based on the 16S rRNA gene sequences showed that these three strains showed high 16S rRNA gene sequence similarity to Flectobacillus roseus GFA-11T (99.2, 98.8 and 99.8 %, respectively) and Flectobacillus rhizosphaerae JC289T (98.8, 98.6 and 99.4 %, respectively), and less than 96.6 % to other species of the genus Flectobacillus. The phylogenetic tree reconstructed based on the 16S rRNA gene sequences showed that strains LYT7WT, DC10W, LFS242WT, F. roseus GFA-11T and F. rhizosphaerae JC289T formed a tight cluster. The phylogenomic tree also supported the above robust phylogenetic relationships. The calculated OrthoANIu and digital DNA-DNA hybridization values between strains LYT7WT and DC10W were 95.2 % and 61.9 %, respectively. Although these values are located in the transition region for species demarcation, the similar physiological and genotypic characteristics supported that strains LYT7WT and DC10W should belong to the same species. The pairwise OrthoANIu and digital DNA-DNA hybridization values between strain LFS242WT and its related strains were less than 91.8 and 45.3 %, respectively, indicating that strain LFS242WT should represent an independent novel species of the genus Flectobacillus. It should be noticed that the pairwise OrthoANIu and digital DNA-DNA hybridization values between strains F. roseus LMG 24501T and F. rhizosphaerae KCTC 42575T were 96.9 and 73.1 %, respectively. The similar physiological and genotypic characteristics also supported that F. rhizosphaerae Ramaprasad et al. 2015 should be a synonym of F. roseus Sheu et al. 2009. Combining the above descriptions, strains LYT7WT, DC10W and LFS242WT should represent two novel species of the genus Flectobacillus, for which the names Flectobacillus longus sp. nov. (type strain LYT7WT=GDMCC 1.3222T=KCTC 92561T) and Flectobacillus rivi sp. nov. (type strain LFS242WT=GDMCC 1.3223T=KCTC 92562T) are proposed.

Description of Aequorivita aurantiaca sp. nov. Isolated from Coastal Sediment, and Comparative Genomic Analysis and Biogeographic Distribution of the Genus Aequorivita.

A novel Gram-stain-negative, facultatively anaerobic, and non-motile bacterial strain, designated SDUM287046T, was isolated from the coastal sediments of Jingzi Port of Weihai, China. Cells of strain SDUM287046T were rod-shaped with widths of 0.4-0.5 μm and lengths of 0.7-1.4 μm and could produce flexirubin-type pigments. Optimum growth of strain SDUM287046T occurred at 33-35 °C, pH 7.0, and with 2% (w/v) NaCl. Oxidase activity was negative, but catalase activity was positive. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain SDUM287046T was most closely related to Aequorivita aquimaris D-24T (98.3%). The main cellular fatty acids were iso-C15:0, anteiso-C15:0, iso-C17:0 3-OH, and summed feature 9 (comprised of iso-C17:1 ω9c and/or C16:0 10-methyl). The sole respiratory quinone was MK-6. The polar lipids consisted of phosphatidylethanolamine (PE), one aminolipid (AL), three unidentified glycolipids (GL), and three unidentified lipids (L). The DNA G + C content was 39.3 mol%. According to the integrated results of phylogenetic, physiological, biochemical, and chemotaxonomic characteristics, we propose that strain SDUM287046T represents a novel species of the genus Aequorivita, for which the name Aequorivita aurantiaca sp. nov. is proposed. The type strain is SDUM287046T (=KCTC 92754T = MCCC 1H01418T). Comparative genomic analysis showed that the 16 Aequorivita species shared 1453 core genes and differed mainly in amino acid metabolism, cofactor metabolism, and vitamin metabolism. Biogeographic distribution analysis indicated that the marine environments were the primary habitat of Aequorivita bacteria.

Acinetobacter entericus sp. nov., isolated from the gut of plastic-eating insect larvae Zophobas atratus.

A Gram-negative, non-motile and rod-shaped strain, BIT-DXN8T, was isolated from the gut of plastic-eating insect larvae Zophobas atratus. The taxonomic position of this new isolate was examined by using a polyphasic approach. A preliminary analysis based on the 16S rRNA gene sequence (1411 bp) indicated that the most similar strain to BIT-DXN8T was Acinetobacter bouvetii DSM 14964T (98.5%), followed by Acinetobacter haemolyticus CIP 64.3T (98.2%) and Acinetobacter pullicarnis S23T (98.2%). The results of phylogenetic analyses, based on the 16S rRNA gene, concatenated sequences of five housekeeping genes (fusA, gyrB, recA, rplB and rpoB) and genome sequences, placed strain BIT-DXN8T in a separate lineage among the genus Acinetobacter of the family Moraxellaceae. The average nucleotide identity and digital DNA-DNA hybridization values of the strain when compared to all other species within the genus Acinetobacter were below 96 and 70 %, respectively. The physiological and biochemical tests confirm the affiliation of strain BIT-DXN8T to the present species within the genus Acinetobacter, but with some specific phenotypic differences. Therefore, strain BIT-DXN8T is considered to represent a novel species, for which the name Acinetobacter entericus sp. nov. is proposed. The type strain is BIT-DXN8T (=CCTCC AB 2022117T=KCTC 92696T).

Corynebacterium hylobatis sp. nov. and Corynebacterium lemuris sp. nov., two novel species of the genus Corynebacterium isolated from faeces of primates.

Two Gram-stain positive, aerobic, short-rod-shaped, catalase-positive, oxidase-negative and non-motile strains, designated YIM 101343T and YIM 101645T, were isolated from faeces of Hylobates hoolock and Lemur catta, respectively. The results of 16S rRNA gene analysis indicated that both represented members of the genus Corynebacterium, and they shared a similarity of 98.0 % with each other. Corynebacterium marinum DSM 44953T showed the highest similarity with both strains YIM 101343T (99.0 %) and YIM 101645T (97.3 %). The results of phylogenetic analysis based on 16S rRNA gene indicated that strain YIM 101343T formed a cluster with C. marinum DSM 44953T and Corynebacterium comes 2019T, strain YIM 101645T formed a cluster with Corynebacterium halotolerans YIM 70093T, and the two clusters were neighbours. The genomic size of strain YIM 101343T was 3068751 bp and that of strain YIM 101645T was 3169714 bp. The dDDH, ANI and AAI values among strains YIM 101343T, YIM 101645T and the closely related species indicated that the two isolates represented two different novel species. Both strains contained meso-diaminopimelic acid and short-chain mycolic acids, and the major menaquinones were MK-9(H2) and MK-8(H2). The major polar lipids of the two strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids (>10 %) of both strains were C16 : 0, summed feature 4 and C18 : 1ω9c, but C17 : 1 ω8c was only present as a major component in YIM 101645T . In addition, phenotypic and some chemotaxonomic characteristics of strains YIM 101343T, YIM 101645T and the closely related species were different. Thus, strains YIM 101343T and YIM 101645T should represent two novel species of the genus Corynebacterium, for which the names Corynebacterium hylobatis sp. nov. and Corynebacterium lemuris sp. nov. are proposed, respectively. The type strains are YIM 101343T (=DSM 45970T=CCTCC AB 2013221T) and YIM 101645T (=BCRC 16963T=CCTCC AB 2013281T=KCTC 39868T).

Description and genome-wide analysis of Profundicola chukchiensis gen. nov., sp. nov., marine bacteria isolated from bottom sediments of the Chukchi Sea.

Two Gram-negative, aerobic halophilic non-motile strains designated KMM 9713 and KMM 9724T were isolated from the bottom sediments sampled from the Chukchi Sea in the Arctic Ocean, Russia. The novel strains grew in 0.5-5% NaCl, at 7-42°C, and pH 5.5-10.5. Phylogenetic analyses based on 16S rRNA gene and whole genome sequences revealed that strains KMM 9713 and KMM 9724T were close to each other and shared the highest 16S rRNA gene sequence similarity of 91.28% with the type strain Ornithobacterium rhinotracheale DSM 15997T and 90.15-90.92% with the members of the genus Empedobacter in the family Weeksellaceae. Phylogenetic trees indicated that strains KMM 9713 and KMM 9724T formed a distinct line adjacent to their relative O. rhinotracheale DSM 15997T. The average nucleotide identity values between strain KMM 9724T and O. rhinotracheale DSM 15997T, Empedobacter brevis NBRC 14943T, and Moheibacter sediminis CGMCC 1.12708T were 76.73%, 75.78%, and 74.65%, respectively. The novel strains contained the predominant menaquinone MK-6 and the major fatty acids of iso-C17:0 3-OH, iso-C15:0 followed by iso-C17:1ω6. Polar lipids consisted of phosphatidylethanolamine, one an unidentified aminophospholipid, two unidentified aminolipids, and two or three unidentified lipids. The DNA G+C contents of 34.5% and 34.7% were calculated from genome sequence of the strains KMM 9713 and KMM 9724T, respectively. Based on the phylogenetic evidence and distinctive phenotypic characteristics, strains KMM 9713 and KMM 9724T are proposed to be classified as a novel genus and species Profundicola chukchiensis gen. nov., sp. nov. The type strain of Profundicola chukchiensis gen. nov., sp. nov. is strain KMM 9724T (= KACC 22806T).

Hymenobacter canadensis sp. nov., isolated from freshwater of the pond in Cambridge Bay, Canada.

A Gram-stain-negative, aerobic, reddish-coloured, rod-shaped and non-motile strain PAMC 29467T, was isolated from freshwater of the pond in Cambridge Bay, Canada. Strain PAMC 29467T was closely related to Hymenobacter yonginensis (98.1 % 16S rRNA gene similarity). Genomic relatedness analyses showed that strain PAMC 29467T is distinguishable from H. yonginensis based on average nucleotide identity (91.3 %) and digital DNA-DNA hybridization values (39.3 %). The major fatty acids (>10 %) of strain PAMC 29467T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C15 : 0 iso, C16 : 1 ω5c and summed feature 4 (C17 : 1 iso l and/or anteiso B). The major respiratory quinone was menaquinone-7. The genomic DNA G+C content was 61.5 mol%. Strain PAMC 29467T was separated from the type species in the genus Hymenobacter by its distinct phylogenetic position and some physiological characteristics. As a result, a novel species is proposed, with the name Hymenobacter canadensis sp. nov. (type strain, PAMC 29467T=KCTC 92787T=JCM 35843T).