Noncanonical contribution of microglial transcription factor NR4A1 to post-stroke recovery through TNF mRNA destabilization.

Microglia-mediated neuroinflammation is involved in various neurological diseases, including ischemic stroke, but the endogenous mechanisms preventing unstrained inflammation is still unclear. The anti-inflammatory role of transcription factor nuclear receptor subfamily 4 group A member 1 (NR4A1) in macrophages and microglia has previously been identified. However, the endogenous mechanisms that how NR4A1 restricts unstrained inflammation remain elusive. Here, we observed that NR4A1 is up-regulated in the cytoplasm of activated microglia and localizes to processing bodies (P-bodies). In addition, we found that cytoplasmic NR4A1 functions as an RNA-binding protein (RBP) that directly binds and destabilizes Tnf mRNA in an N6-methyladenosine (m6A)-dependent manner. Remarkably, conditional microglial deletion of Nr4a1 elevates Tnf expression and worsens outcomes in a mouse model of ischemic stroke, in which case NR4A1 expression is significantly induced in the cytoplasm of microglia. Thus, our study illustrates a novel mechanism that NR4A1 posttranscriptionally regulates Tnf expression in microglia and determines stroke outcomes.

c-Abl-induced Olig2 phosphorylation regulates the proliferation of oligodendrocyte precursor cells.

Oligodendrocytes (OLs), the myelinating cells in the central nervous system (CNS), are differentiated from OL progenitor cells (OPCs). The proliferation of existing OPCs is indispensable for myelination during CNS development and remyelination in response to demyelination stimulation. The transcription factor Olig2 is required for the specification of OLs and is expressed in the OL lineage. However, the post-translational modification of Olig2 in the proliferation of OPCs is poorly understood. Herein, we identified that c-Abl directly phosphorylates Olig2 mainly at the Tyr137 site, and that Olig2 phosphorylation is essential for OPC proliferation. The expression levels of c-Abl gradually decreased with brain development; moreover, c-Abl was highly expressed in OPCs. OL-specific c-Abl knockout at the developmental stage led to an insufficient proliferation of OPCs, a decreased expression of myelin-related genes, and myelination retardation. Accordingly, a c-Abl-specific kinase inhibitor suppressed OPC proliferation in vitro. Furthermore, we observed that OL-specific c-Abl knockout reduced OPC proliferation and remyelination in a cuprizone model of demyelination. In addition, we found that nilotinib, a clinically used c-Abl inhibitor, decreased the expression of myelin basic protein (Mbp) and motor coordination in mice, indicating a neurological side effect of a long-term administration of the c-Abl inhibitor. Thus, we identified the important role of c-Abl in OLs during developmental myelination and remyelination in a disease model.

Arthrobacter wenxiniae sp. nov., a novel plant growth-promoting rhizobacteria species harbouring a carotenoids biosynthetic gene cluster.

A bacterial strain, designated AETb3-4T was isolated from the rhizosphere of lily. Comparison of 16S rRNA gene sequences showed that the sequence from strain AETb3-4T exhibits high sequence similarity with those of Arthrobacter silviterrae KIS14-16T (97.9%), Arthrobacter livingstonensis LI2T (97.2%) and Arthrobacter stackebrandtii CCM 2783T (97.0%). Whole genome average nucleotide identity (ANI) and the digital DNA-DNA hybridization (dDDH) values between strain AETb3-4T and the reference strains A. silviterrae DSM 27180T, A. livingstonensis L12T and A. stackebrandtii DSM 16005T were below 83.6% and 27.7%, respectively, values which are considerably below the proposed thresholds for the species delineation, consistent with the proposal that strain AETb3-4T represents a novel species. The genome size of strain AETb3-4T is 4.33 Mb and the genomic DNA G + C content is 67.3%. The main polar lipids were identified as phosphatidylglycerol, diphosphatidylglycero, phosphatidylinositol and an unidentified glycolipid. The major fatty acids (> 10%) were identified as anteiso-C15: 0 and anteiso-C17: 0. The predominant menaquinone was found to be menaquinone 9 (MK-9) (H2) (82.2%). Phenotypic tests allowed the strain to be differentiated from its close phylogenetic neighbors. Based on the results obtained, it is proposed that the strain AETb3-4T (= CFCC 16390T = LMG 31708T) represents a novel species in the genus Arthrobacter, for which the names Arthrobacter wenxiniae sp. nov. is proposed. In addition, the novel strain AETb3-4T has multiple plant growth-promoting characters including ACC-deaminase activity and production of IAA. Furthermore, the genome contains secondary metabolite biosynthesis gene clusters, including a carotenoid biosynthetic gene cluster, suggesting potential capacities for secondary metabolite synthesis. These data suggest that strain AETb3-4T may have potential applications both in medicine and sustainable agriculture.

Isolation and screening of stress-resistant endophytic fungus strains from wild and cultivated soybeans in cold region of China.

In this study, we firstly reported the large-scale screening and isolation of endophytic fungi from nine wild and six cultivated soybeans in the cold regions of China. We totally isolated 302 endophytic fungal strains, of which 215 strains are isolated from the wild soybeans and 87 are identified from cultivated soybeans. Among these endophytic fungal strains, in the roots, stems, and leaves, 24.17% were isolated from roots, 28.8% were isolated from stems, and 47.01% were isolated from leaves, respectively. Most endophytic fungal strains isolated from the wild soybean roots were the species of Fusarium genus, and the fungal strains in the stems were the species of ascomycetes and Fusarium fungi, whereas most strains in the leaves were Alternaria fungi. To analyze the taxonomy of the obtained samples, we sequenced and compared their rDNA internal transcribed spacer (ITS) sequences. The data showed that 6 strains are putatively novel strains exhibiting ≤ 97% homology with the known strains. We next measured the secondary metabolites produced by the different strains and we found 11 strains exhibited high-performance synthesis of triterpenoids, phenols, and polysaccharides. Furthermore, we characterized their tolerance to abiotic stresses. The results indicated that 4 strains exhibited high tolerance to cadmium, and some strains exhibited resistance to acid, and alkali. The results of the study could facilitate the further exploration of the diversity of plant endophytic fungi and the potential applications of the fungi to practical agriculture and medicine industries. KEY POINTS: • 302 endophytic fungal strains isolated from wild soybean and cultivated soybean • 11 strains had high contents of triterpenoids, phenols, and polysaccharides • 4 strains exhibited high Cd tolerance, and a few strains with strong tolerance to acid and alkali solution.

Caulobacter endophyticus sp. nov., an endophytic bacterium harboring three lasso peptide biosynthetic gene clusters and producing indoleacetic acid isolated from maize root.

A novel Gram-stain-negative, aerobic and rod-shaped bacterium with a single polar flagellum or a stalk at the end of the cell, was isolated from maize roots in the Fangshan District of Beijing, People's Republic of China. The new strain designated 774T produced indole acetic acid (IAA). The 16S rRNA gene sequence analysis indicated that strain 774T belongs to the genus Caulobacter and is closely related to Caulobacter flavus RHGG3T, Caulobacter zeae 410Tand Caulobacter radices 695T, all with sequence similarities of 99.9%. The genome size of strain774T was 5.4 Mb, comprising 5042 predicted genes with a DNA G+C content of 68.7%.Three striking lasso peptide biosynthetic gene clusters and two IAA synthesis genes belonging to the TPM pathway were also found in the genome of strain 774T. The average nucleotide identity values and digital DNA-DNA hybridization values of the strain774T with its closely phylogenetic neighbours were less than 91.5% and 45.0%, respectively, indicating a new Caulobacter species. The major fatty acids of strain774T were identified as C16: 0 (27.7%), summed feature 3 (C16: 1ω6c and/or C16: 1ω7c) (12.6%) and summed feature 8 (C18: 1ω7c and/or C18: 1ω6c) (42.9%).The major polar lipids consisted of phosphatidyl-glycerol and glycolipids. The predominant ubiquinone was identified as Quinone 10. Based on the polyphasic characterization, strain 774T represents a novel species of the genus Caulobacter, for which the name Caulobacter endophyticus sp. nov. is proposed with 774T (= CGMCC 1.16558T = DSM 106777T) as the type strain.

Paenibacillus apii sp. nov., a novel nifH gene-harbouring species isolated from the rhizospheres of vegetable plants grown in different regions of northern China.

Two nifH gene-harbouring bacterial strains were isolated from rhizospheres of different vegetable plants grown in different regions of northern PR China. The two strains possessed almost identical 16S rRNA gene sequences. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains were 99.21 and 93.6% respectively, suggesting they belong to one species. Based on 16S rRNA gene phylogeny, the two strains were clustered together with Paenibacillus rhizophilus 7197T, Paenibacillus sabinae T27T and Paenibacillus forsythiae T98T, but on a separate branch. Novelty of the species was confirmed by ANI and dDDH comparisons between the type strain 7124T and its closest relatives, since the obtained values were considerably below the proposed thresholds for the species delineation. The genome size of strain 7124T was 5.40 Mb, comprising 5050 predicted genes with a DNA G+C content of 52.3 mol%. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and three unidentified lipids. The major cellular fatty acids were anteiso-C15  :  0 (52.9%) and C16  :  0 (23.4 %). Menaquinone-7 was reported as the major respiratory quinone. The diamino acid in the cell-wall peptidoglycan was found to be meso-diaminopimelic acid. Based on phylogenetic, genomic, chemotaxonomic and phenotypic data, the two isolates are considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus apii sp. nov. is proposed, with 7124T (=DSM 103172T=CGMCC 1.15689T) as type strain.

Rhizobium rhizophilum sp. nov., an indole acetic acid-producing bacterium isolated from rape (Brassica napus L.) rhizosphere soil.

A novel Gram-stain-negative, aerobic, rod-shaped and indole acetic acid-producing strain, designated 7209-2T, was isolated from rhizosphere of rape (Brassica napus L.) grown in the Yakeshi City, Inner Mongolia, PR China. The 16S rRNA gene sequence analysis indicated that strain 7209-2T belongs to the genus Rhizobium and is closely related to Rhizobium rosettiformans W3T, Rhizobium ipomoeae shin9-1T and Rhizobium wuzhouense W44T with sequence similarities of 98.2, 98.1 and 97.9 %, respectively. Phylogenetic analysis based on concatenated housekeeping recA and atpD gene sequences showed that strain 7209-2T formed a group together with R. wuzhouense W44T and R. rosettiformans W3T, with sequences similarities of 92.6 and 91.1 %, respectively. The genome size of strain 7209-2T was 5.25 Mb, comprising 5027 predicted genes with a DNA G+C content of 61.2 mol%. The average nucleotide identity and digital DNA-DNA hybridization comparisons among 7209-2T and reference strains for the most closely related species showed values below the accepted threshold for species discrimination. The major fatty acids of strain 7209-2T were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and summed feature 2 (C12 : 0 aldehyde and/or unknown 10.953) . The major polar lipids were found to consist of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and an unidentified aminophospholipid. The predominant ubiquinone was identified as quinone 10. Based on all the above results, strain 7209-2T represents a novel species of the genus Rhizobium, for which the name Rhizobium rhizophilum sp. nov. is proposed with 7209-2T (=CGMCC 1.15691T=DSM 103161T) as the type strain.

Mesorhizobium rhizophilum sp. nov., a 1-aminocyclopropane-1-carboxylate deaminase producing bacterium isolated from rhizosphere of maize in Northeast China.

A novel 1-aminocyclopropane-1-carboxylate deaminase producing bacterium, Gram- stain-negative, aerobic, motile, rod-shaped strain designated YM1C-6-2T was isolated from rhizosphere of maize grown in Northeast China. The 16S rRNA gene sequence analysis indicated that strain YM1C-6-2T belongs to the genus Mesorhizobium and is closely related to Mesorhizobium alhagi CCNWXJ12-2T and M. camelthorni CCNWXJ40-4T with sequence similarities of 98.4% and 97.9%, respectively. Multilocus sequence analysis of other housekeeping genes revealed that the new isolates YM1C-6-2T forms a phylogenetically group with some species in the genus Mesorhizobium. The genome size of strain YM1C-6-2T was 5.51 Mb, comprising 5378 predicted genes with a DNA G+C content of 64.5%. The average nucleotide identity and digital DNA-DNA hybridization comparisons between YM1C-6-2T and the most related type strains showed values below the accepted threshold for species discrimination. The major fatty acids of strain YM1C-6-2T were C19:0 cyclo ω8c (47.5%), summed feature 8 (C18:1ω7c and/or C18:1ω6c) (19.5%) and C16:0 (15.1%), which differed from the closely related reference strains in their relative abundance. The major polar lipids consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified aminophospholipid. The predominant ubiquinone was identified as Quinone 10. Phenotypic and biochemical analysis results indicated that strain YM1C-6-2T can be distinguished from closely related type strains. Based on the above results, strain YM1C-6-2T represents a novel species of the genus Mesorhizobium, for which the name Mesorhizobium rhizophilum sp. nov. is proposed with YM1C-6-2T (= CGMCC 1.15487T = DSM 101712T) as the type strain.

Paenibacillus rhizophilus sp. nov., a nitrogen-fixing bacterium isolated from the rhizosphere of wheat (Triticum aestivum L.).

A novel Gram-stain-variable, endospore-forming, motile, rod-shaped, facultative aerobic bacterium, designated 7197T, was isolated from rhizosphere soil of wheat (Triticum aestivum L.) collected from Yakeshi County, Inner Mongolia, PR China. This isolate was found to have the highest 16S rRNA gene sequence similarity to Paenibacillussabinae T27T (98.0 %), followed by Paenibacillussophorae S27T (97.9 %) and Paenibacillusforsythiae T98T (97.7 %). To ascertain the genomic relatedness of this strain to its phylogenetic neighbours, its genome sequence was determined. The average nucleotide identity values of genome sequences between the novel isolate and the type strains of related species P. sabinae T27T, P. sophorae S27T and P. forsythiae T98T were 87.9 %, 85.8 and 83.9 %, respectively. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unidentified aminophospholipids and one unidentified aminolipid. The major cellular fatty acids were anteiso-C15 : 0 (56.3 %), C16 : 0 (15.7 %) and iso-C15 : 0 (14.1 %).The genome size of strain 7197T was 5.21 Mb, comprising 4879 predicted genes with a DNA G+C content of 51.9 mol%. Menaquinone-7 was reported as the major respiratory quinone. The diamino acid in the cell-wall peptidoglycan was found to be meso-diaminopimelic acid. Based on phylogenetic, genomic, chemotaxonomic and phenotypic characteristics, strain 7197T was classified as a novel species within the genus Paenibacillus, for which the name Paenibacillus rhizophilus sp. nov. is proposed. The type strain of Paenibacillus rhizophilus is 7197T (=DSM 103168T=CGMCC 1.15699T).

c-Abl inhibition mitigates diet-induced obesity through improving insulin sensitivity of subcutaneous fat in mice.

AIMS/HYPOTHESIS: High-energy diets are among the main causes of the global epidemic of metabolic disorders, including obesity and type 2 diabetes. The mechanisms of high-energy-diet-induced metabolic disorders are complex and largely unknown. The non-receptor tyrosine kinase c-Abl plays an important role in adipogenesis in vitro but its role in vivo in the regulation of metabolism is still elusive. Hence, we sought to address the role of c-Abl in diet-induced obesity and obesity-associated insulin resistance. METHODS: The expression of c-Abl in different fat tissues from obese humans or mice fed a high-fat diet (HFD) were first analysed by western blotting and quantitative PCR. We employed conditional deletion of the c-Abl gene (also known as Abl1) in adipose tissue using Fabp4-Cre and 6-week-old mice were fed with either a chow diet (CD) or an HFD. Age-matched wild-type mice were treated with the c-Abl inhibitor nilotinib or with vehicle and exposed to either CD or HFD, followed by analysis of body mass, fat mass, glucose and insulin tolerance. Histological staining, ELISA and biochemical analysis were used to clarify details of changes in physiology and molecular signalling. RESULTS: c-Abl was highly expressed in subcutaneous fat from obese humans and HFD-induced obese mice. Conditional knockout of c-Abl in adipose tissue improved insulin sensitivity and mitigated HFD-induced body mass gain, hyperglycaemia and hyperinsulinaemia. Consistently, treatment with nilotinib significantly reduced fat mass and improved insulin sensitivity in HFD-fed mice. Further biochemical analyses suggested that c-Abl inhibition improved whole-body insulin sensitivity by reducing HFD-triggered insulin resistance and increasing adiponectin in subcutaneous fat. CONCLUSIONS/INTERPRETATION: Our findings define a new biological role for c-Abl in the regulation of diet-induced obesity through improving insulin sensitivity of subcutaneous fat. This suggests it may become a novel therapeutic target in the treatment of metabolic disorders.

Rhizobium wenxiniae sp. nov., an endophytic bacterium isolated from maize root.

A novel Gram-stain-negative, aerobic, rod-shaped strain designated 166T was isolated from surface-sterilized root tissue of maize planted in the Fangshan District of Beijing, PR China. The 16S rRNA gene sequence analysis indicated that strain 166T belongs to the genus Rhizobium and is closely related to Rhizobium cellulosilyticum ALA10B2T and Rhizobium yantingense H66T with sequence similarities of 98.8 and 98.3 %, respectively. According to atpD and recA sequence analysis, the highest sequence similarity between strain 166T and R. cellulosilyticum ALA10B2T is 93.8 and 84.7 %, respectively. However, the new isolate exhibited relatively low levels of DNA-DNA relatedness with respect to R. cellulosilyticum DSM 18291T (20.8±2.3 %) and Rhizobium yantingense CCTCC AB 2014007T (47.2±1.4 %). The DNA G+C content of strain 166T was 59.8 mol%. The main polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, an unidentified aminophospholipid and an unidentified aminolipid. The major fatty acids of strain 166T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The results of the physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 166T from the type strains of closely related species, R. cellulosilyticum DSM 18291T and R. yantingense CCTCC AB 2014007T. Strain 166T represents a novel species within the genus Rhizobium, for which the name Rhizobium wenxiniae sp. nov. is proposed, with the type strain 166T (=CGMCC 1.15279T=DSM 100734T).

Pedobacter zeae sp. nov., an endophytic bacterium isolated from maize root.

A novel Gram-staining-negative, aerobic, non-motile by gliding and rod-shaped strain, designated 22T, was isolated from surface-sterilized root tissue of maize planted in the Fangshan District of Beijing, PR China. The highest levels of 16S rRNA gene sequence similarity were found with respect to Pedobacter suwonensis 15-52T (97.5 %), Pedobacter terrae DS-57T (97.1 %) and Pedobacter alluvionis NWER-II11T (97.0 %). Phylogenetic analysis based on 16S rRNA gene sequence data indicated that strain 22T is a member of the genus Pedobacter. The isolate exhibited relatively low levels of DNA-DNA relatedness with respect to P. suwonensis DSM 18130T (21.3±2.0 %), P. alluvionis DSM 19624T (38.1±1.8 %) and P. terrae DSM 17933T (17.1±1.4 %). The DNA G+C content was 41.2±0.5 mol%. The major isoprenoid quinone was menaquinone-7 (MK-7). The major component in the polyamine pattern was sym-homospermidine. The major polar lipids consisted of phosphatidylethanolamine, three unidentified aminolipids and one unidentified lipid. The major fatty acids were identified as iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The results of the physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 22T from the related species with high 16S rRNA gene sequence similarity, P. suwonensis DSM 18130T, P. alluvionis DSM 19624T and P. terrae DSM 17933T. Strain 22T represents a novel species within the genus Pedobacter, for which the name Pedobacter zeae sp. nov. is proposed, with the type strain 22T (=CGMCC 1.15287T=DSM 100774T).

Microbacterium zeae sp. nov., an endophytic bacterium isolated from maize stem.

A novel Gram-stain positive, aerobic, non-motile, non-spore-forming and rod-shaped strain designated 1204T was isolated from surface-sterilised stem tissue of maize planted in Fangshan District of Beijing, People's Republic of China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belongs to the genus Microbacterium. High levels of 16S rRNA gene sequence similarity were found between strain 1204T and Microbacterium enclense NIO-1002T (98.8%) and Microbacterium proteolyticum RZ36T (98.4%) respectively. However, the DNA-DNA hybridization values between strain 1204T and its closely related species M. proteolyticum DSM 27100T and M. enclense DSM 25125T were 53.9 ± 1.6 and 20.9 ± 1.5% respectively. The DNA G+C content of strain 1204T was determined to be 68.0 mol%. The major fatty acids were found to consist of anteiso-C15:0 (37.6%), iso-C16:0 (28.6%) and anteiso-C17:0 (16.6%). The predominant menaquinone was MK-11 and the polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, an unidentified glycolipid and an unidentified lipid. The results of physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 1204T from the closely related species in the genus Microbacterium. Thus, it was concluded that strain 1204T represents a novel species within the genus Microbacterium, for which the name Microbacterium zeae sp. nov. is proposed, with the type strain 1204T (= CGMCC 1.15289 = DSM 100750).

Lentibacillus populi sp. nov., a moderately halophilic, endophytic bacterium isolated from a poplar tree, and emended description of the genus Lentibacillus.

A Gram-staining-positive, moderately halophilic, aerobic, endospore-forming, rod-shaped bacterial strain, designated WD4L-1T was isolated from surface-sterilized stem tissue of a poplar tree planted in the Wudalianchi National Geopark of Heilongjiang province, PR China. This novel isolate grew in the presence of 0-15 % (w/v) NaCl, at pH 6.0-9.0 and 15-50 °C; optimum growth was observed with 7-8 % (w/v) NaCl, at pH 7.0 and 30 °C. The 16S rRNA gene sequence analysis indicated that the strain WD4L-1T belonged to the genus Lentibacillus, and was most closely related to Lentibacillus garicola SL-MJ1T with a sequence similarity of 96.1 %. The DNA G+C content of strain WD4L-1T was determined to be 36.9 mol%. The respiratory quinone was identified as menaquinone-7 (MK-7) and the major lipids were diphosphatidylglycerol and phosphatidylglycerol and one unidentified phospholipid. The major fatty acids of strain WD4L-1T were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0. The results of the physiological and biochemical tests and the minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain WD4L-1T from the closely related Lentibacillus garicola JCM 30131T. Thus, strain WD4L-1T represents a novel species of the genus Lentibacillus, for which the name Lentibacillus populi sp. nov. is proposed. The type strain is WD4L-1T (=CGMCC 1.15454T=DSM 101738T). An emended description of the genus Lentibacillus is also provided.

Dyadobacter endophyticus sp. nov., an endophytic bacterium isolated from maize root.

A novel Gram-stain-negative, aerobic and rod-shaped bacterial strain, designated 65T, was isolated from surface-sterilized root tissue of maize, collected from Fangshan District of Beijing, People's Republic of China, and was subjected to a taxonomic study by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 65T belonged to the genus Dyadobacter and had highest 16S rRNA gene sequence similarity to Dyadobacter jiangsuensis CGMCC 1.12969T (99.1 %), Dyadobacter beijingensis CGMCC 1.6375T (98.8 %), Dyadobacter fermentans DSM 18053T (98.6 %) and Dyadobacter soli KCTC 22481T (98.6 %). However, the new isolate exhibited relatively low levels of DNA-DNA relatedness with respect to D. jiangsuensis CGMCC 1.12969T (18.2±1.3 %), D. beijingensis CGMCC 1.6375T (14.2±2.0 %), D. fermentans DSM 18053T (14.1±2.0 %) and D. soli KCTC 22481T (13.8±0.6 %). The predominant respiratory quinone was menaquinone-7 (MK-7) and the major cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1ω5c, iso-C15 : 0 3-OH, C16 : 0 3-OH and C16 : 0. The polar lipid profile of strain 65T revealed the presence of phosphatidylethanolamine, four aminolipids and two unidentified phospholipids. The DNA G+C content was 46.6 mol%. The results of physiological and biochemical tests and the differences in the fatty acid profiles allowed the clear phenotypic differentiation of strain 65T from closely related species of the genus Dyadobacter. Strain 65T thus represents a novel species within the genus Dyadobacter, for which the name Dyadobacterendophyticus sp. nov. is proposed. The type strain is 65T (=CGMCC 1.15288T=DSM 100786T).

Sphingomonaszeicaulis sp. nov., an endophytic bacterium isolated from maize root.

A novel Gram-staining-negative, aerobic and rod-shaped strain designated 541T was isolated from surface-sterilized root tissue of maize, collected from the Fangshan District of Beijing, People's Republic of China, and was subjected to a taxonomic study using a polyphasic approach. According to a phylogenetic tree based on 16S rRNA gene sequences, strain 541T represented a member of the genus Sphingomonas and clustered with Sphingomonas sanxanigenens DSM 19645T, with which it shared the highest 16S rRNA gene sequence similarity (98.8 %). The predominant respiratory quinone was ubiquinone-10 (Q-10), the major polyamine was sym-homospermidine and the major cellular fatty acids were C18 : 1ω7c (50.9 %), C16 : 0 (22.0 %) and C14 : 0 2-OH (11.4 %). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and sphingoglycolipid. The DNA G+C content was 64.7 mol%. DNA-DNA relatedness between strain 541T and its closest phylogenetic relative Sphingomonas sanxanigenens DSM 19645T was 50.8 %. The results of physiological and biochemical tests and the differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 541T from closely related species of the genus Sphingomonas. Strain 541T represents a novel species within the genus Sphingomonas, for which the nameSphingomonas zeicaulis sp. nov. is proposed, with the type strain 541T (=CGMCC 1.15008T=DSM 100587T).

Paenibacillus radicis sp. nov., an endophytic bacterium isolated from maize root.

A novel Gram-stain-positive, aerobic, endospore-forming, and rod-shaped strain designated 694T was isolated from surface-sterilized root tissue of a maize planted in the Fangshan District of Beijing, People's Republic of China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belongs to the genus Paenibacillus. High levels of 16S rRNA gene sequence similarity were found between strain 694T and Paenibacillus xinjiangensis DSM 30034T (98.5 %) and Paenibacillus glycanilyticus (98.1 %), respectively. However, the DNA-DNA hybridization values between strain 694T and its close relatives P. xinjiangensis 16970T and Paenibacillus algorifonticola CGMCC 1.10223T were 30.0 % and 36.7 % respectively. The DNA G+C content of strain 694T was determined to be 46.9 mol%. The predominant respiratory quinone was identified as menaquinone-7 and the polar lipid profile was found to be composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were found to be anteiso-C15 : 0 (42.1 %), iso-C15 : 0 (18.4 %), iso-C16 : 0 (11.2 %) and C16 : 0 (12.1 %). The results of physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 694T from the closely related species in the genus Paenibacillus. Strain 694T is concluded to represent a novel species within the genus Paenibacillus, for which the name Paenibacillus radicis sp. nov. is proposed, with the type strain 694T ( = CGMCC 1.15286T = DSM 100762T).

Filimonas zeae sp. nov., an endophytic bacterium isolated from maize root.

A novel Gram-stain-negative, aerobic, motile by gliding and filamentous strain, designated 772T,was isolated from surface-sterilized root tissue of maize planted in the Fangshan District of Beijing, China. 16S rRNA gene sequence analysis indicated that strain 772T was closely related to Filimonas endophytica SR2-06T andFilimonas lacunae YT21T of the family Chitinophagaceae with sequence similarities of 99.0 and 96.9 %, respectively. However, the new isolate exhibited relatively low levels of DNA-DNA relatedness with respect to Filimonas. endophytica KCTC 42060T (18.7±1.8 %) and Filimonas. lacunae DSM 21054T (17.9±2.0%). The DNA G+C content of strain 772T was 44.9 mol%. The respiratory quinone was menaquinone-7 and the polar lipid profile consisted of phosphatidylethanolamine, two unidentified aminophospholipids, two unidentified phospholipids and one unidentified lipid. The major fatty acids were iso-C15 : 0 and iso-C15 : 1 G. The results of the physiological and biochemical tests and minor differences in the fatty acid profiles allowed the clear phenotypic differentiation of strain 772T from the closely related species Filimonas. endophytica andF. lacunae. Strain 772T thus represents a novel species within the genus Filimonas, for which the name Filimonas zeae sp. nov. is proposed. The type strain is 772T (=CGMCC 1.15290T=DSM 100760T).

Flavobacterium endophyticum sp. nov., a nifH gene-harbouring endophytic bacterium isolated from maize root.

A novel Gram-stain-negative, aerobic, rod-shaped bacterium, designated strain 522T, was isolated from surface-sterilized root tissue of maize planted in Fangshan District of Beijing, China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belonged to the genus Flavobacterium and showed less than 93.9 % similarity to the type strains of all recognized species of the genus Flavobacterium. The predominant respiratory quinone was menaquinone-6 and the polar lipid profile was composed of the major lipids phosphatidylethanolamine, phosphatidylserine and two unidentified amino lipids. The major fatty acids were C15 : 0, iso-C15 : 0, iso-C15 : 1 G and iso-C16 : 0.The G+C content of the DNA was 37.7 mol%. The results of physiological and biochemical tests and the differences in fatty acid profiles allowed the clear phenotypic differentiation of strain 522T from closely related species of the genus Flavobacterium. Strain 522T therefore represents a novel species within the genus Flavobacterium, for which the name Flavobacterium endophyticum sp. nov. is proposed. The type strain is 522T ( = ACCC 19708T = DSM 29537T).