Endophytic Streptomyces sp. NEAU-DD186 from Moss with Broad-Spectrum Antimicrobial Activity: Biocontrol Potential Against Soilborne Diseases and Bioactive Components.

Soilborne diseases cause significant economic losses in agricultural production around the world. They are difficult to control because a host plant is invaded by multiple pathogens, and chemical control often does not work well. In this study, we isolated and identified an endophytic Streptomyces sp. NEAU-DD186 from moss, which showed broad-spectrum antifungal activity against 17 soilborne phytopathogenic fungi, with Bipolaris sorokiniana being the most prominent. The strain also exhibited strong antibacterial activity against soilborne phytopathogenic bacteria Ralstonia solanacearum. To evaluate its biocontrol potential, the strain was prepared into biofertilizer by solid-state fermentation. Response surface methodology was employed to optimize the fermentation conditions for maximizing spore production and revealed that the 1:1 ratio of vermicompost to wheat bran, a temperature of 28°C, and 50% water content with an inoculation amount of 15% represented the optimal parameters. Pot experiments showed that the application of biofertilizer with a spore concentration of 108 CFU/g soil could effectively suppress the occurrence of tomato bacterial wilt caused by R. solanacearum and wheat root rot caused by B. sorokiniana, and the biocontrol efficacy was 81.2 and 72.2%, respectively. Chemical analysis of strain NEAU-DD186 extracts using nuclear magnetic resonance spectrometry and mass analysis indicated that 25-O-malonylguanidylfungin A and 23-O-malonylguanidylfungin A were the main active constituents, which showed high activity against R. solanacearum (EC50 of 2.46 and 2.58 µg ml-1) and B. sorokiniana (EC50 of 3.92 and 3.95 µg ml-1). In conclusion, this study demonstrates that Streptomyces sp. NEAU-DD186 can be developed as biofertilizer to control soilborne diseases.

Mumia quercus sp. nov., isolated from the root of Quercus variabilis.

A novel endophytic actinomycete, designated strain NEAU-365T, was isolated from the root of Quercus variabilis collected from Nanjing, Jiangsu, PR China. Comparative 16S rRNA gene sequencing showed that strain NEAU-365T belonged to the genus Mumia but clearly differs from the currently recognized species Mumia zhuanghuii Z350T (99.31 %), Mumia xiangluensis NEAU-KD1T (98.82 %) and Mumia flava MUSC 201T (97.78 %). Phylogenetic tree analysis revealed that strain NEAU-365T clustered with the type strains of the genus Mumia. The genome size was 4.1 Mbp with a DNA G+C content of 71.2 mol%. Digital DNA-DNA hybridization and average nucleotide identity values between the genome sequence of strain NEAU-365T and those of M. zhuanghuii Z350T(27.5 and 84.0 %), M. xiangluensis NEAU-KD1T(23.4 and 80.9 %) and M. flava MUSC 201T(20.9 and 77.7 %) were below the recommended thresholds for species delineation. Cells were observed to be irregular cocci shaped. The cell wall contained ll-diaminopimelic acid and the whole-cell sugars were galactose and rhamnose. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid and three unidentified phospholipids. The predominant menaquinone was detected as MK-9(H4). The major fatty acids were C16 : 0, C18 : 0, C18 : 1 ω9c and 10-methyl C18 : 0. On the basis of genotypic and phenotypic differences from members of the genus Mumia, a novel species, Mumia quercus sp. nov. is proposed. The type strain is NEAU-365T (=CCTCC AA 2021033T=JCM 35005T).

Sphaerisporangium perillae sp. nov., isolated from the root of Perilla frutescens (Linn.) Britt.

A novel protease-producing actinomycete, designated strain NEAU-ZS1T, was isolated from the root of Perilla frutescens (Linn.) Britt collected from Jiamusi, Heilongjiang, PR China. Comparative 16S rRNA gene sequencing showed that strain NEAU-ZS1T belonged to the genus Sphaerisporangium and was most closely related to 'Sphaerisporangium corydalis' NEAU-YHS15T (99.2%) and Sphaerisporangium cinnabarinum JCM 3291T (99.0%). Phylogenetic tree analysis revealed that strain NEAU-ZS1T formed a monophyletic clade with 'S. corydalis' NEAU-YHS15T. The genome size was 9.3 Mbp with a DNA G+C content of 70.3 mol%. Digital DNA-DNA hybridization, average nucleotide identity and average amino acid identity values between the genome sequence of strain NEAU-ZS1T and those of 'S. corydalis' NEAU-YHS15T (28.6, 83.9 and 79.1 %) and S. cinnabarinum JCM 3291T (18.5, 70.6 and 50.2 %) were below the recommended thresholds for species delineation. The strain formed spherical spore vesicles produced on the aerial hyphae. The cell wall contained meso-diaminopimelic acid and the whole-cell sugars were glucose and madurose. The polar lipids consisted of diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylinositol, an unidentified phospholipid and an unidentified glycolipid. The menaquinones were MK-9(H4), MK-9(H6) and MK-9(H2). The major fatty acids were iso-C16 : 0, C16 : 1 ω5c, 10-methy C17 : 0 and C17 : 1 ω7c. On the basis of the results of a polyphasic taxonomic study, it is concluded that strain NEAU-ZS1T represents a novel species of the genus Sphaerisporangium, for which the name Sphaerisporangium perillae sp. nov. is proposed. The type strain is NEAU-ZS1T (=CCTCC AA 2021019T= JCM 35655T).

The Transcription Factors WRKY41 and WRKY53 Mediate Early Flowering Induced by the Novel Plant Growth Regulator Guvermectin in Arabidopsis thaliana.

Flowering is a crucial stage for plant reproductive success; therefore, the regulation of plant flowering has been widely researched. Although multiple well-defined endogenous and exogenous flowering regulators have been reported, new ones are constantly being discovered. Here, we confirm that a novel plant growth regulator guvermectin (GV) induces early flowering in Arabidopsis. Interestingly, our genetic experiments newly demonstrated that WRKY41 and its homolog WRKY53 were involved in GV-accelerated flowering as positive flowering regulators. Overexpression of WRKY41 or WRKY53 resulted in an early flowering phenotype compared to the wild type (WT). In contrast, the w41/w53 double mutants showed a delay in GV-accelerated flowering. Gene expression analysis showed that flowering regulatory genes SOC1 and LFY were upregulated in GV-treated WT, 35S:WRKY41, and 35S:WRKY53 plants, but both declined in w41/w53 mutants with or without GV treatment. Meanwhile, biochemical assays confirmed that SOC1 and LFY were both direct targets of WRKY41 and WRKY53. Furthermore, the early flowering phenotype of 35S:WRKY41 lines was abolished in the soc1 or lfy background. Together, our results suggest that GV plays a function in promoting flowering, which was co-mediated by WRKY41 and WRKY53 acting as new flowering regulators by directly activating the transcription of SOC1 and LFY in Arabidopsis.

Isolation and Biosynthesis of Phenazine-Polyketide Hybrids from Streptomyces sp. KIB-H483.

A phenazine-polyketide hybrid compound, nexphenazine A (1), was isolated from Streptomyces sp. KIB-H483. The bioinformatic analysis of the draft genome of the producing strain and gene inactivation experiments revealed that the biosynthesis of 1 involves a phenazine-polyketide hybrid gene cluster. The abolished production of 1 as well as the accumulation of shunt metabolites 4-7 in mutant strain ΔnpzI revealed the key role of the npzI gene, which encodes an NAD(P)H-dependent ketoreductase, in nexphenazine biosynthesis. The structures and absolute configurations of the isolated intermediates were established on the basis of spectroscopic data analysis, single-crystal X-ray diffraction, chiral chromatography, and chemical conversion experiments. NpzI exhibited stereochemical selectivity in reducing the carbonyl group of 4. Nexphenazine biosynthesis is proposed to involve a condensation of the carboxyl group of phenazine with one molecule of methylmalonyl-CoA by a type I PKS, followed by a ketone reduction by NpzI and an unknown methylation reaction.

Streptomyces typhae sp. nov., a novel endophytic actinomycete with antifungal activity isolated the root of cattail (Typha angustifolia L.).

A novel endophytic actinomycete with antagonistic activity against various phytopathogenic fungi, designated strain p1417T, was isolated from the root of cattail (Typha angustifolia L.) collected from Yunnan Province, Southwest China. A polyphasic taxonomic study was carried out to establish the taxonomic status of this strain. Strain p1417T was found to have morphological and chemotaxonomic characteristics typical of the genus Streptomyces. The diamino acid present in the cell wall was LL-diaminopimelic acid. Xylose and arabinose occurred in whole cell hydrolysates. The menaquinones were identified as MK-9(H8), MK-9(H6) and MK-9(H4). The polar lipid profile was found to contain diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were found to be iso-C16:0, anteiso-C15:0, iso-C15:0 and C16:0. The genomic DNA G + C content of strain p1417T based on the genome sequence was 72.0 mol%. Based on 16 S rRNA gene, five housekeeping genes and whole genome sequences analysis, strain p1417T was most closely related to Streptomyces flavofungini JCM 4753T (99.4% 16 S rRNA gene sequence similarity), Streptomyces alboflavus JCM 4615T (98.8%) and Streptomyces aureoverticillatus JCM 4347T (98.2%). However, the average nucleotide identity values, the digital DNA-DNA hybridization values and the multilocus sequence analysis evolutionary distances between this strain and its closely related strains showed that it belonged to one distinct species. In addition, these results were also supported by differences in the phenotypic and chemotaxonomic characteristics between strain p1417T and three closely related type strains. Therefore, it is concluded that strain p1417T represents a novel species of the genus of Streptomyces, for which the name Streptomyces typhae sp. nov. is proposed. The type strain is p1417T (= CCTCC AA 2019091T = DSM 110636T).

Nonomuraea typhae sp. nov., an endophytic actinomycete isolated from the root of cattail pollen (Typha angustifolia L.).

A novel endophytic actinomycete, designated strain p1410T, was isolated from the root of cattail pollen (Typha angustifolia L.) and characterized using a polyphasic approach. The strain had morphological characteristics and chemotaxonomic properties identical to those of members of the genus Nonomuraea. It produced spiral chains of spores on aerial mycelium as well as forming a pseudosporangium. Whole-cell hydrolysates contained meso-diaminopimelic acid, glucose, ribose and madurose. The menaquinones detected were MK-9(H2), MK-9(H4) and MK-9(H0). The major fatty acids were 10-methyl C17 : 0, iso-C16 : 0 and C17 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol mannoside and an unknown glycolipid. The DNA G+C content of the draft genome sequence, consisting of 11.4 Mbp, was 70.9 mol%. Phylogenetic analysis of 16S rRNA gene sequences showed that strain p1410T belongs to the genus Nonomuraea with the highest sequence similarity to Nonomuraea candida HMC10T (98.6 %), but phylogenetically clustered with Nonomuraea endophytica YIM 65601T (98.4 %) and Nonomuraea longicatena NRRL 15532T (98.3 %). Based on its phenotypic characteristics, DNA-DNA relatedness and average nucleotide identity, the strain is considered to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea typhae sp. nov. is proposed. The type strain is p1410T (=CCTCC AA 2019044T=JCM 33461T).

Actinomadura physcomitrii sp. nov., a novel actinomycete isolated from moss [Physcomitrium sphaericum (Ludw) Fuernr].

A novel endophytic actinomycete, designated strain LD22T, was isolated from moss [Physcomitrium sphaericum (Ludw) Fuernr] collected from Yunnan Province, Southwest China. A polyphasic taxonomic study was carried out to establish the status of this strain. Morphological and chemotaxonomic characteristics of strain LD22T confirmed the affiliation of the isolate to the genus Actinomadura. The diamino acid present in the cell wall is meso-diaminopimelic acid. Glucose, madurose, galactose and ribose occur in whole cell hydrolysates. The menaquinones were identified as MK-9(H4), MK-9(H8), MK-9(H6) and MK-9(H2). The polar lipid profile was found to contain diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The major fatty acids were found to be C16:0, 10-methyl C18:0 and C18:1 ω9c. The DNA G + C content of the draft genome sequence, consisting of 10.0 Mbp, was 72.5%. Phylogenetic analysis of 16S rRNA gene sequences showed that strain LD22T belongs to the genus Actinomadura with the highest sequence similarity to Actinomadura montaniterrae CYP1-1BT (99.2%). However, phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate formed a phyletic line with Actinomadura rudentiformis HMC1T (98.6%). The low level of DNA-DNA relatedness and some different phenotypic characteristics allowed the strain to be distinguished from the above-mentioned two strains. Therefore, it is concluded that strain that strain LD22T represents a novel species of the genus of Actinomadura, for which the name Actinomadura physcomitrii sp. nov. is proposed. The type strain is LD22T (= CCTCC AA 2018050T = JCM 33455T).

Characterization of the N-methyltransferases involved in the biosynthesis of toxoflavin, fervenulin and reumycin from Streptomyces hiroshimensis ATCC53615.

Toxoflavin (1), fervenulin (2), and reumycin (3), known to be produced by plant pathogen Burkholderia glumae BGR1, are structurally related 7-azapteridine antibiotics. Previous biosynthetic studies revealed that N-methyltransferase ToxA from B. glumae BGR1 catalyzed the sequential methylation at N6 and N1 in pyrimido[5,4-e]-as-triazine-5,7(6H,8H)-dione (4) to generate 1. However, the N8 methylation of 4 in the biosynthesis of fervenulin remains unclear. To explore the N-methyltransferases required for the biosynthesis of 1 and 2, we identified and characterized the fervenulin and toxoflavin biosynthetic gene clusters in S. hiroshimensis ATCC53615. On the basis of the structures of intermediates accumulated from the four N-methyltransferase gene inactivation mutants and systematic enzymatic methylation reactions, the tailoring steps for the methylation order in the biosynthesis of 1 and 2 were proposed. The N-methylation order and routes for the biosynthesis of fervenulin and toxoflavin in S. hiroshimensis are more complex and represent an obvious departure from those in B. glumae BGR1.

Streptomyces capitiformicae sp. nov., a novel actinomycete producing angucyclinone antibiotics isolated from the head of Camponotus japonicus Mayr.

A novel actinomycete, designated strain 1H-SSA4T, was isolated from the head of an ant (Camponotus japonicus Mayr) and was found to produce angucyclinone antibiotics. A polyphasic approach was used to determine the taxonomic status of strain 1H-SSA4T. The DNA G+C content of the draft genome sequence, consisting of 11.4 Mbp, was 70.0 mol%. 16S rRNA gene sequence similarity studies showed that strain 1H-SSA4T belongs to the genus Streptomyces with the highest sequence similarity to Streptomyces hygroscopicus subsp. ossamyceticus NBRC 13983T (98.9 %), and phylogenetically clustered with this species, Streptomyces torulosus LMG 20305T (98.8 %), Streptomyces ipomoeae NBRC 13050T (98.5 %) and Streptomyces decoyicus NRRL 2666T (98.4 %). The morphological and chemotaxonomic properties of the strain were also consistent with those members of the genus Streptomyces. A combination of DNA-DNA hybridization experiments and phenotypic tests were carried out between strain 1H-SSA4T and the above-mentioned strains, which further clarified their relatedness and demonstrated that strain 1H-SSA4T could be distinguished from these strains. Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces capitiformicae sp. nov. is proposed. The type strain is 1H-SSA4T (=CGMCC 4.7403T=DSM 104537T).

Glycomyces tritici sp. nov., isolated from rhizosphere soil of wheat (Triticum aestivum L.) and emended description of the genus Glycomyces.

A novel actinomycete strain, designated NEAU-C2T, was isolated from rhizosphere soil of wheat (Triticum aestivum L.), and subjected to a polyphasic taxonomic study. Morphological and chemotaxonomic properties of this strain were consistent with the description of the genus Glycomyces. Growth was found to occur at a temperature range of 15-40 °C, pH 6-10 and NaCl concentrations of 0-4%. The cell wall was found to contain meso-diaminopimelic acid and the whole cell sugars were identified as galactose, xylose and ribose. The predominant menaquinones were identified as MK-10(H6) and MK-10(H2). The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylinositol, phosphatidylglycerol, phosphoglycolipids and an unidentified glycolipid. The major fatty acids were identified as anteiso-C15:0, iso-C16:0, anteiso-C17:0 and iso-C15:0. 16S rRNA gene sequence similarity studies showed that strain NEAU-C2T belongs to the genus Glycomyces with high sequence similarity to Glycomyces algeriensis NRRL B-16327T (99.0% sequence similarity). Some physiological and biochemical properties and low DNA-DNA relatedness values enabled the strain to be differentiated from closely related species of the genus Glycomyces. It is concluded that the isolate can be classified as representing a novel species of the genus Glycomyces, for which the name Glycomyces tritici is proposed. The type strain is NEAU-C2T (= DSM 104644T = CGMCC 4.7410T).

Streptomyces flavalbus sp. nov., an actinobacterium isolated from rhizosphere of maize (Zea mays L.).

A novel actinobacterium, designated strain NEAU-QY24T, was isolated from the rhizosphere of corn (Zea mays L.). A polyphasic approach was employed to determine the taxonomic status of strain NEAU-QY24T. The isolate was found to have chemical and morphological properties of the genus Streptomyces, with high 16S rRNA gene sequence similarity to Streptomyces lanatus JCM 4332T (98.3%) and clustered phylogenetically with Streptomyces lannensis JCM 16578T (98.2%). The cell wall was found to contain meso-diaminopimelic acid and the whole cell sugars were identified as glucose and ribose. The predominant menaquinones were identified as MK-9(H6), MK-9(H4) and MK-9(H8). The phospholipid profile was found to consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were identified as iso-C16:0, C16:0, anteiso-C17:0 and C15:0. A combination of DNA-DNA hybridization experiments and phenotypic tests were carried out between strain NEAU-QY24T and its closely related strains, which clarified their relatedness and demonstrated that strain NEAU-QY24T could be distinguished from these strains. These data indicate that the isolate should be recognised as a new species of the genus Streptomyces, for which the name Streptomyces flavalbus sp. nov. is proposed. The type strain is NEAU-QY24T (= CGMCC 4.7400T = DSM 104539T).

Streptomyces lasii sp. nov., a Novel Actinomycete with Antifungal Activity Isolated from the Head of an Ant (Lasius flavus).

During a screening for novel and biotechnologically useful actinobacteria in insects, a novel actinobacteria with antifungal activity, designated strain 5H-CA11T, was isolated from the head of an ant (Lasius flavus) and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. 16S rRNA gene sequence analysis showed that strain 5H-CA11T is a member of the genus Streptomyces, with the highest sequence similarity to Streptomyces scabrisporus DSM 41855T (98.9%). Similarities to other type strains of the genus Streptomyces were lower than 96%. Phylogenetic analysis based on the 16S rRNA gene sequence also indicated that strain 5H-CA11T clusters with S. scabrisporus DSM 41855T using two tree-making algorithms. DNA-DNA hybridization between strain 5H-CA11T and S. scabrisporus JCM 11712T revealed 33.6% similarity, supporting the phenotypic and phylogenetic differences found between these two strains. Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces lasii sp. nov. is proposed. The type strain is 5H-CA11T (=CGMCC 4.7303T = DSM 102043T).

Streptomyces castaneus sp. nov., a novel actinomycete isolated from the rhizosphere of Peucedanum praeruptorum Dunn.

During an investigation of microbial diversity in medicinal herbs, a novel actinomycete, strain NEAU-QHHV11T was isolated from the rhizosphere of Peucedanum praeruptorum Dunn collected from Xianglu Mountain in Heilongjiang Province, northeast China and characterized using a polyphasic approach. The organism was found to have typical characteristics of the genus Streptomyces. Phylogenetic analysis based on 16S rRNA gene sequence also indicated that strain NEAU-QHHV11T belongs to the genus Streptomyces and was most closely related to Streptomyces graminilatus NBRC 108882T (98.7 % sequence similarity) and Streptomyces turgidiscabies NBRC 16080T (98.7 % sequence similarity). The results of DNA-DNA hybridization and some phenotypic characteristics indicated that strain NEAU-QHHV11T could be distinguished from its close phylogenetic relatives. Thus, strain NEAU-QHHV11T represents a novel species of the genus Streptomyces, for which the name Streptomyces castaneus sp. nov. is proposed. The type strain is NEAU-QHHV11T (=CGMCC 4.7235T = DSM 100520T).

Two new species of the genus Streptomyces: Streptomyces camponoti sp. nov. and Streptomyces cuticulae sp. nov. isolated from the cuticle of Camponotus japonicus Mayr.

Two novel actinomycetes, designated strains 2C-SSA16(2)T and 1C-GS8T, were isolated from the cuticle of Camponotus japonicus Mayr, collected from Northeast Agricultural University, Heilongjiang Province, north China. Both of them contained genes (involved in antibiotics biosynthesis) of the ketosynthase (KS) and methyl malonyl transferase domains (PKS-I) and the adenylation domain (NRPS). A polyphasic study was carried out to establish the taxonomic positions of these strains. The 16S rRNA gene sequence analysis showed that the two novel isolates 2C-SSA16(2)T and 1C-GS8T exhibited 98.8% similarity with each other and that they are most closely related to Streptomyces umbrinus JCM 4521T (99.0, 98.6%), Streptomyces ederensis JCM 4958T (98.9, 98.7%), Streptomyces aurantiacus JCM 4453T (98.6, 98.2%), Streptomyces glomeroaurantiacus JCM 4677T (98.6, 98.1%), Streptomyces tauricus JCM4837T (98.2, 98.0%) and Streptomyces phaeochromogenes JCM 4070T (98.2, 99.2%). The corresponding phylogenetic analysis based on partial gyrB gene sequences showed that strains 2C-SSA16(2)T and 1C-GS8T formed a cluster with the above-mentioned strains. The DNA-DNA hybridization data and phenotypic characteristics indicated that strains 2C-SSA16(2)T and 1C-GS8T could be readily distinguished from each other and their closest phylogenetic relatives. Therefore, these two strains are suggested to represent two novel species of the genus Streptomyces, for which the names Streptomyces camponoti sp. nov. and Streptomyces cuticulae sp. nov. are proposed. The type strains are 2C-SSA16(2)T (=CGMCC 4.7276T = DSM 100522T) and 1C-GS8T (=CGMCC 4.7348 = DSM 103127T), respectively.

Longispora urticae sp. nov., isolated from rhizosphere soil of Urtica urens L., and emended descriptions of the species Longisporaalbida and Longisporafulva.

Two Gram-stain-positive, aerobic actinomycete strains, designated NEAU-PCY-3T and NEAU-PCY-4, were isolated from rhizosphere soil of Urtica urens L. collected from Anshan, Liaoning Province, northeast PR China. The 16S rRNA gene sequence analysis showed that the two strains exhibited 99.9 % 16S rRNA gene sequence similarity with each other and that they were most closely to Longispora fulva DSM 45356T (98.7, 98.9 %) and Longispora albida JCM 11711T (97.1, 97.2 %). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that the two strains were located in the same lineage and formed a cluster with the genus Longispora. Both strains were observed to contain MK-10(H4) and MK-10(H6) as the predominant menaquinones. The cell wall peptidoglycan was found to contain meso-diaminopimelic acid, d-glutamic acid, glycine and l-alanine. Whole-cell hydrolysates mainly contained galactose, ribose and xylose. The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, several glycolipids and several unknown lipids. The major cellular fatty acids for strain NEAU-PCY-3T were iso-C16 : 0, iso-C17 : 0, anteiso-C17 : 0 and C18 : 1ω5c. The DNA-DNA hybridization value between strains NEAU-PCY-3T and NEAU-PCY-4 was 83.6±0.4 %, and the values between the two strains and their closest phylogenetic relatives, belonging to the genus Longispora, were well below 70 %, supporting that they represented a distinct genomic species. An array of phenotypic characteristics also differentiated the strains from their closely related species, the only two validly published Longispora species. On the basis of the genetic, chemotaxonomic and phenotypic properties, strains NEAU-PCY-3T and NEAU-PCY-4 were classified as representatives of a novel species of the genus Longispora, for which the name Longispora urticae sp. nov. is proposed. The type strain is NEAU-PCY-3T (=DSM 105119T=CCTCC AA 2017017T).

Promicromonospora soli sp. nov., a novel actinomycete isolated from soil.

A novel actinobacterium, designated strain NEAU-GS50T, was isolated from soil collected from Mount Song and characterized by using a polyphasic approach. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the organism should be assigned to the genus Promicromonospora and that it forms a monophyletic clade with its closest relatives Promicromonospora umidemergens JCM 17975T (98.94 % 16S rRNA gene sequence similarity), Promicromonospora alba 1C-HV12T (98.82 %) and Promicromonospora kermanensis DSM45485T (98.68 %). Similarly, chemotaxonomic data including major menaquinones, fatty acid compositions and polar lipid profiles, also supported the placement of strain NEAU-GS50T in the genus Promicromonospora. However, DNA-DNA relatedness, physiological and biochemical data showed that strain NEAU-GS50T could be distinguished from its closest relatives. Therefore, strain NEAU-GS50T represents a novel species of the genus Promicromonospora, for which the name Promicromonospora soli sp. nov. is proposed, with strain NEAU-GS50T (CGMCC4.7398T=DSM 104515T) as the type strain.

Streptomyces amphotericinicus sp. nov., an amphotericin-producing actinomycete isolated from the head of an ant (Camponotus japonicus Mayr).

A novel actinomycete, designated strain 1H-SSA8T, was isolated from the head of an ant (Camponotus japonicus Mayr) and was found to produce amphotericin. A polyphasic approach was employed to determine the status of strain 1H-SSA8T. Morphological and chemotaxonomic characteristics were consistent with those of members of the genus Streptomyces. The menaquinones detected were MK-9(H6), MK-9(H8) and MK-9(H4). The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine and phosphatidylinositol mannoside. The major fatty acids were identified as iso-C16 : 0, C16 : 0, C15 : 0 and anteiso-C15 : 0. Analysis of the 16S rRNA gene sequence showed that strain 1H-SSA8T belongs to the genus Streptomyces with high sequence similarity to Streptomyces ramulosus NRRL B-2714T (99.2 %). Two tree-making algorithms based on 16S rRNA gene sequences showed that the isolate formed a phyletic line with Streptomyces himastatinicus ATCC 53653T (98.7 %). The MLSA utilizing partial sequences of the housekeeping genes (atpD, gyrB, recA, rpoB and trpB) also supported the position. However, evolutionary distances were higher than the 0.007 MLSA evolutionary distance threshold proposed for species-level relatedness. Moreover, the low level of DNA-DNA relatedness and phenotypic differences allowed the novel isolate to be differentiated from its most closely related strain S. ramulosus NRRL B-2714T and strain S. himastatinicus ATCC 53653T. It is concluded that the organism can be classified as representing a novel species of the genus Streptomyces, for which the name Streptomyces amphotericinicus sp. nov. is proposed. The type strain is 1H-SSA8T (=CGMCC 4.7350T=DSM 103128T).

Micromonospora parathelypteridis sp. nov., an endophytic actinomycete with antifungal activity isolated from the root of Parathelypteris beddomei (Bak.) Ching.

A novel endophytic actinomycete with antifungal activity, designated strain NEAU-JXY5T, was isolated from the root of Parathelypteris beddomei (Bak.) Ching. Strain NEAU-JXY5T showed closest 16S rRNA gene sequence similarity to Micromonospora luteifusca GUI2T (99.31 %), and phylogenetically clustered with Micromonospora noduli GUI43T (99.24 %), 'Micromonospora lycii' NEAU-gq11 (99.19 %), 'Micromonospora zeae' NEAU-gq9 (99.12 %), Micromonospora saelicesensis Lupac 09T (98.97 %), Micromonospora vinacea GUI63T (98.96 %), 'Micromonospora jinlongensis' NEAU-GRX11 (98.91 %), Micromonospora profundi DS3010T (98.77 %), Micromonospora zamorensis CR38T (98.76 %), Micromonospora chokoriensis 2-19(6)T (98.71 %), Micromonospora lupini Lupac 14NT (98.69 %), Micromonospora ureilytica GUI23T (98.69 %), Micromonospora violae NEAU-zh8T (98.57 %) and Micromonospora taraxaci NEAU-P5T (98.37 %). Phylogenetic analysis based on gyrB gene sequences also indicated that the isolate clustered with the above strains except M. violae NEAU-zh8T. A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that the strain could be readily distinguished from these closest phylogenetic relatives. Therefore, it is concluded that strain NEAU-JXY5T represents a novel species of the genus Micromonospora, for which the name Micromonospora parathelypteridis sp. nov. is proposed. The type strain is NEAU-JXY5T (=CGMCC 4.7347T=DSM 103125T).

Bacillus solisilvae sp. nov., isolated from forest soil.

A novel Gram-stain-positive, motile, endospore-forming, rod-shaped bacterial strain, NEAU-cbsb5T, was isolated from forest soil from Changbai Mountain, Heilongjiang Province, China. The isolate grew at 15-40 °C (optimum 30 °C), at pH 6.0-8.0 (optimum pH 7.0) and in the presence of up to 4 % (w/v) NaCl, although NaCl was not required for growth. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain NEAU-cbsb5T formed a distinct lineage within the genus Bacillus and was most closely related to Bacillus acidiceler DSM 18954T (99.1 % similarity) and Bacillus luciferensis JCM 12212T (99.0 %). 16S rRNA gene sequence similarity to sequences of the type strains of other Bacillus species was less than 96.0 %. Average nucleotide identity (ANI) values between NEAU-cbsb5T and its most closely related species were 78.72-84.75 % by ANIm, ANIb and OrthoANIu analysis. The in silico DNA-DNA hybridization values between strain NEAU-cbsb5T and its close relatives B. acidiceler DSM 18954T and B. luciferensis JCM 12212T were both 23.80 %, again indicating they belong to different taxa. The major cellular fatty acids of NEAU-cbsb5T were iso-C15 : 0, anteiso-C15 : 0 and C16 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unknown aminophospholipid. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the predominant menaquinones were MK-7 and MK-6. The genomic DNA G+C content was 33.0 mol%. Based on the phylogenetic, phenotypic and chemotaxonomic data, strain NEAU-cbsb5T was classified as a representative of a novel species in the genus Bacillus, for which the name Bacillus solisilvae sp. nov. is proposed. The type strain is NEAU-cbsb5T (=CGMCC 1.14993T=DSM 100485T).