Nonomuraea solani sp. nov., an actinomycete isolated from eggplant root (Solanum melongena L.)

Genomic and physiological characterization of Kitasatospora sp. nov., an actinobacterium with potential for biotechnological application isolated from Cerrado soil

An Actinobacteria - Kitasatospora sp. K002 - was isolated from the soil of Cerrado, a savanna-like Brazilian biome. Herein, we conducted a phylogenetic, phenotypic and physiological characterization, revealing its potential for biotechnological applications. Kitasatospora sp. K002 is an aerobic, non-motile, Gram-positive bacteria that forms grayish-white mycelium on solid cultures and submerged spores with vegetative mycelia on liquid cultures. The strain showed antibacterial activity against Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli. Genomic analysis indicated that Kitasatospora xanthocidica JCM 4862 is the closest strain to K002, with a dDDH of 32.8-37.8% and an ANI of 86.86% and the pangenome investigations identified a high number of rare genes. A total of 60 gene clusters of 22 different types were detected by AntiSMASH, and 22 gene clusters showed low similarity (< 10%) with known compounds, which suggests the potential production of novel bioactive compounds. In addition, phylogenetic analysis and morphophysiological characterization clearly distinguished Kitasatospora sp. K002 from other related species. Therefore, we propose that Kitasatospora sp. K002 should be recognized as a new species of the genus Kitasatospora - Kitasatospora brasiliensis sp. nov. (type strains = K002).

Nonomuraea sediminis sp. nov., a novel actinobacterium with antimicrobial activity, isolated from sediment of Dianchi Lake

A novel actinobacterium with antimicrobial activity, designated strain H16431^T, was isolated from a sediment sample collected from Dianchi Lake, Yunnan Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain H16431^T was most closely related to Nonomuraea rhizosphaerae CGMCC 4.7431^T and Nonomuraea guangzhouensis CGMCC 4.7101^T (98.1% similarity), but formed a monophyletic clade with Nonomuraea ceibae KCTC 39826^T (98.0% similarity). Phylogenomic analysis based on whole-genome sequence showed that strain H16431^T formed a separate clade within the genus Nonomuraea. The average nucleotide identity, average amino acid identity, and digital DNA-DNA hybridization values between strain H16431^T and its closely related Nonomuraea species were 80.0-81.5%, 71.2-74.6%, and 23.2-25.0%, respectively, which were significantly lower than the widely accepted species-defined threshold. The DNA G + C content was 70.2% based on the whole-genome sequence. The menaquinones were identified as MK-9(H₄), MK-9(H₆), and MK-9(H₂). The major fatty acids were iso-C_16:0, 10 methyl-C_17:0, and iso-C_16:0 2OH. The phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, and phosphatidylinositol. These chemotaxonomic characteristics were corresponded to those of the genus Nonomuraea. On the basis of the taxonomic evidence, strain H16431^T represents a novel species of the genus Nonomuraea, for which the name Nonomuraea sediminis sp. nov. is proposed. The type strain is H16431^T (=JCM 34852^T=CICC 25119^T).

Description of a new strain of Streptomonospora nanhaiensis and reclassification of Streptomonospora halotolerans as a later heterotypic synonym of Streptomonospora nanhaiensis

A novel actinomycete, designated strain NEAU-YY374, was isolated from root of wheat and a polyphasic taxonomic study was carried out. 16S rRNA gene sequence analysis indicated that strain NEAU-YY374 was closely related to Streptomonospora halotolerans NEAU-Jh2-17^T (99.3 %) and Streptomonospora nanhaiensis 12A09^T (98.6%). Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain NEAU-YY374 formed a stable clade with S. halotolerans NEAU-Jh2-17^T and S. nanhaiensis 12A09^T in trees generated with two algorithms. Key morphological and chemotaxonomic properties also confirmed the affiliation of strain NEAU-YY374 to the genus Streptomonospora. The differences of DNA G+C contents among these three strains were all less than 1 %, and the digital DNA-DNA hybridization and the average nucleotide identity values were higher than the circumscription thresholds of species and subspecies, clearly indicating that the three strains should belong to the same species. Therefore, we concluded that strain NEAU-YY374 is a new strain of S. nanhaiensis. Meanwhile, S. halotolerans should be reclassified as a later heterotypic synonym of S. nanhaiensis according to the priority of publication and validation of the name.

Nonomuraea aurantiaca sp. nov., a novel cellulase-producing actinobacterium isolated from soil

A novel cellulase-producing actinobacterium, designated strain NEAU-L178T, was isolated from soil sample collected from Qiqihaer, Heilongjiang Province, PR China. A polyphasic study was carried out to determine the taxonomic status of the strain. On the basis of 16S rRNA gene sequence analysis, strain NEAU-L178T should be classified into the genus Nonomuraea and is closely related to Nonomuraea cavernae SYSU K10005T (99.31 % 16S rRNA gene sequence similarity), Nonomuraea glycinis NEAU-BB2C19T (98.75 %), Nonomuraea guangzhouensis NEAU-ZJ3T (98.75 %) and ‘Nonomuraea rhizosphaerae’ NEAU-mq18T (98.34 %). The digital DNA–DNA hybridization values between them are 27.1, 26.1, 42.0 and 30.9 %, and the whole-genome average nucleotide identity values between them are 83.1, 82.3, 90.3 and 85.8 %, respectively. The whole-cell hydrolysates contained glucose, ribose, arabinose and madurose. The menaquinones were identified as MK-9(H0), MK-9(H4) and MK-9(H2). The major fatty acids were C16 : 0, iso-C17 : 0 and C17 : 0 10-methyl. The detected polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol and three unidentified phospholipids. The genomic DNA G+C content was 69.7 mol%. In addition, whole-genome analysis indicated that strain NEAU-L178T had the potential to degrade cellulose. Based on the phenotypic, genotypic, chemotaxonomic and phylogenetic data, strain NEAU-L178T can be differentiated from its close phylogenetic relatives and represents a novel species of the genus Nonomuraea , for which the name Nonomuraea aurantiaca sp. nov. is proposed. The type strain is NEAU-L178T (=JCM 34799T=CGMCC 4.7741T).

Streptacidiphilus fuscans sp. nov., a novel actinobacterium isolated from the root of pumpkin (Cucurbita moschata)

A novel acidophilic actinobacterium, designated strain NEAU-YB345^T, was isolated from a pumpkin root collected from Mudanjiang, Heilongjiang Province, northeast PR China. Based on 16S rRNA gene sequence similarity and chemotaxonomic and morphological properties, the isolate was assigned to the genus Streptacidiphilus, with the high 16S rRNA gene sequence similarities to Streptacidiphilus melanogenes JCM 16224^T (99.2 %), Streptacidiphilus anmyonensis JCM 16223^T (99.1 %) and Streptacidiphilus jiangxiensis JCM 12277^T (98.7 %). Its cell wall contained ll-diaminopimelic acid as the major diamino acid. Rhamnose, ribose, glucose and galactose were the detected sugars from the whole-cell hydrolysates. The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The menaquinones were MK-9(H₈) and MK-9(H₆). Major fatty acids were C_16 : 0, iso-C_16 : 0, iso-C_15 : 0 and anteiso-C_15 : 0. Phylogenetic analysis using 16S rRNA gene and whole-genome sequences placed the strain in distinct clades but within the genus Streptacidiphilus. The DNA G+C content was 71.2 mol%. Based on DNA-DNA relatedness and physiological and biochemical data, the isolate could be distinguished from its closest relatives. Therefore, strain NEAU-YB345^T represents a novel species of the genus Streptacidiphilus, for which the name Streptacidiphilus fuscans sp. nov. is proposed. The type strain is NEAU-YB345^T (=CCTCC AA 2020030^T=JCM 33976^T).

Nonomuraea cypriaca sp. nov., isolated from soil

A novel actinobacterium, designated strain K274^T, was isolated from soil collected from Zafer Cape (Cape Apostolos Andreas), the easternmost tip of Cyprus on the Karpas peninsula, Magusa, Northern Cyprus, and a polyphasic approach was used for characterization of the strain. The isolate was found to have chemotaxonomic and morphological properties associated with members of the genus Nonomuraea. The strain has the highest similarity to Nonomuraea zeae DSM 100528^T with 99.1% similarity value. In the phylogenetic dendogram based on 16S rRNA gene sequence, strain K274^T was formed a distinct clade together N. zeae DSM 100528^T, 'Nonomuraea basaltis' 160415 (98.9% similarity), and 'Nonomuraea lycopersici' NEAU-DE8(1) (98.2% similarity). The genome sequence of strain K274^T was 11.5 Mbp in size with a total of 11,848 protein-coding genes and 75 RNA genes. The genomic G + C content of the novel strain was 69.7 mol%. Both average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) results between the strain and phlyogenetic neighbours were well below the threshold value, and the novelty are supported by phenotypic and chemotaxonomic differences. Because of all these, strain K274^T represents a novel species in the genus Nonomuraea, for which the name Nonomuraea cypriaca sp. nov. is proposed. The type strain is K274^T (= DSM 45718^T = KCTC 29095^T).

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

A novel endophytic actinomycete, designated strain p1410^T, 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 C_17 : 0, iso-C_16 : 0 and C_17 : 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 p1410^T belongs to the genus Nonomuraea with the highest sequence similarity to Nonomuraea candida HMC10^T (98.6 %), but phylogenetically clustered with Nonomuraea endophytica YIM 65601^T (98.4 %) and Nonomuraea longicatena NRRL 15532^T (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 p1410^T (=CCTCC AA 2019044^T=JCM 33461^T).

Phyllospheric Microbiomes: Diversity, Ecological Significance, and Biotechnological Applications

The phyllosphere referred to the total aerial plant surfaces (above-ground portions), as habitat for microorganisms. Microorganisms establish compositionally complex communities on the leaf surface. The microbiome of phyllosphere is rich in diversity of bacteria, fungi, actinomycetes, cyanobacteria, and viruses. The diversity, dispersal, and community development on the leaf surface are based on the physiochemistry, environment, and also the immunity of the host plant. A colonization process is an important event where both the microbe and the host plant have been benefited. Microbes commonly established either epiphytic or endophytic mode of life cycle on phyllosphere environment, which helps the host plant and functional communication with the surrounding environment. To the scientific advancement, several molecular techniques like metagenomics and metaproteomics have been used to study and understand the physiology and functional relationship of microbes to the host and its environment. Based on the available information, this chapter describes the basic understanding of microbiome in leaf structure and physiology, microbial interactions, especially bacteria, fungi, and actinomycetes, and their adaptation in the phyllosphere environment. Further, the detailed information related to the importance of the microbiome in phyllosphere to the host plant and their environment has been analyzed. Besides, biopotentials of the phyllosphere microbiome have been reviewed.

Polyphasic classification of Nonomuraea strains isolated from the Karakum Desert and description of Nonomuraea deserti sp. nov., Nonomuraea diastatica sp. nov., Nonomuraea longispora sp. nov. and Nonomuraea mesophila sp. nov

Five actinobacteria isolates, KC201^T, KC401, KC310^T, KC712^T and 6K102^T, were recovered from the Karakum Desert during an investigation of novel actinobacteria with biotechnological potential. A polyphasic approach confirmed the affiliation of the strains to the genus Nonomuraea. The strains showed chemotaxonomic and morphological properties consistent with their classification in the genus Nonomuraea. Furthermore, these strains clearly distinguished and formed well supperted clades in phylogenetic and phylogenomic trees. Low ANI and dDDH values and distinguishing phenotypic properties between isolates KC201^T, KC310^T, KC712^T and 6K102^T showed that these strains belonged to novel Nonomuraea species, the names proposed for these taxa are Nonomuraea deserti sp. nov., Nonomuraea diastatica sp. nov., Nonomuraea longispora sp. nov. and Nonomuraea mesophila sp. nov., with the type strains KC310^T (=CGMCC 4.7331^T =DSM 102919^T =KCTC 39774^T), KC712^T (=CGMCC 4.7334^T =DSM 102925^T =KCTC 39776), KC201^T (=CGMCC 4.7339^T =DSM 102917^T =KCTC 39781^T) and 6K102^T (=CGMCC 4.7541^T =JCM 32916), respectively.

Emerging Fungal Infections in the Era of Antibiotic Stewardship

Pneumonia is one of the most common causes of infection seen worldwide and still remains one of the most common causes of mortality despite significant advancements in medicine. With the increase in immunosuppression and antimicrobial usage, emerging infectious agents have been isolated in patients with pneumonia. The authors present a case in which Nonomuraea solani, Candida glabrata, and Candida dubliniensis were isolated from a bronchoalveolar lavage from an immunosuppressed patient with pneumonia.

Jiangella rhizosphaerae sp. nov., an actinomycete isolated from the rhizosphere soil of wheat (Triticum aestivum L.)

A novel actinomycete, designated strain NEAU-YY265^T, was isolated from rhizosphere soil of wheat (Triticum aestivum L.) and characterized using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain NEAU-YY265^T belonged to the genus Jiangella and exhibited 16S rRNA gene sequence similarities of 99.1 and 99.1 % to Jiangella mangrovi 3SM4-07^T and Jiangella alkaliphila D8-87^T. The chemotaxonomic properties of strain NEAU-YY265^T were consistent with those of the genus Jiangella: the cell-wall peptidoglycan type was based on ll-diaminopimelic acid; the whole-cell hydrolysates contained glucose, ribose and rhamnose; MK-9(H4) and MK-9(H2) were the predominant menaquinones. The novel strain produced branching mycelium which fragmented into short or elongated rods. The major fatty acids (>5 %) were anteiso-C15 : 0, anteiso-C17 : 0, C17 : 1ω8c, iso-C16 : 0, C17 : 0 and iso-C15 : 0. The DNA G+C content was 72.6 mol%. Strain NEAU-YY265^T was phenotypically distinct from recognized Jiangella species and shown to belong to a separate genomic species based on DNA-DNA hybridization results. Thus, strain NEAU-YY265^T is considered to represent a novel species of the genus Jiangella, for which the name Jiangella rhizosphaerae sp. nov. is proposed. The type strain is NEAU-YY265^T (=JCM 32551^T=CGMCC 4.7475^T).

Nonomuraea lactucae sp. nov., a novel actinomycete isolated from rhizosphere soil of lettuce (Lactuca sativa)

A novel actinobacterium, designated strain NEAU-YG30T, was isolated from the rhizosphere soil of lettuce collected in Heilongjiang province, north-east China. The taxonomic position of the strain was investigated using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain NEAU-YG30T belongs to the genus Nonomuraea, and shared highest sequence similarity to Nonomuraea muscovyensis KCTC 29233T (97.9 %) and Nonomuraea indica CCTCC AA 209050T (97.6 %). The major menaquinone was identified as MK-9(H4). The major fatty acids were 10-methyl C17 : 0, C17 : 0, iso-C16 : 0 2-OH, iso-C16 : 0 and C16 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxyl-phosphatidylethanolamine, phosphatidylinositol, an unidentified phospholipid and three unidentified lipids. The genomic DNA G+C content of strain NEAU-YG30T was 70.5 mol%. DNA-DNA hybridization values between them were less than 70 %. On the basis of phenotypic, genotypic and phylogenetic data, strain NEAU-YG30T can be characterized to represent a novel species of the genus Nonomuraea, for which the name Nonomuraealactucae sp. nov. is proposed. The type strain is NEAU-YG30T (=JCM 32549T=CGMCC 4.7506T).

Sphaerimonospora triticiradicis sp. nov., a novel actinomycete isolated from a root of wheat (Triticum aestivum L.)

A novel actinomycete, designated strain NEAU-HRGS1-10^T, was isolated from a root of wheat (Triticum aestivum L.) collected from Zhumadian, Henan Province, Central China and characterised using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of members of the genus Sphaerimonospora. The major menaquinones and the whole cell hydrolysates were identified as MK-9(H₄) and MK-9(H₂) and meso-diaminopimelic acid and madurose, respectively. The phospholipid profile was found to contain diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides, phosphatidylmonomethylethanolamine, a phosphoglycolipid, an unidentified lipid and an unidentified phospholipid. The major fatty acids were identified as iso-C_16:0 and 10-methyl C_17:0. The 16S rRNA gene sequence analysis showed that strain NEAU-HRGS1-10^T is closely related to Sphaerimonospora mesophila JCM 3151^T (99.0%), Sphaerimonospora cavernae NBRC 111481^T (97.9%) and Sphaerimonospora thailandensis NBRC 107569^T (97.4%). However, DNA-DNA relatedness, cultural and physiological and biochemical data showed that strain NEAU-HRGS1-10^T can be distinguished from its close relatives. Therefore, it is proposed that strain NEAU-HRGS1-10^T represents a novel species of the genus Sphaerimonospora, for which the name Sphaerimonospora triticiradicis sp. nov. is proposed. The type stain is NEAU-HRGS1-10^T (= CGMCC 4.7401^T = DSM 104915^T).

Genome-Based Taxonomic Classification of the Phylum Actinobacteria

The application of phylogenetic taxonomic procedures led to improvements in the classification of bacteria assigned to the phylum Actinobacteria but even so there remains a need to further clarify relationships within a taxon that encompasses organisms of agricultural, biotechnological, clinical, and ecological importance. Classification of the morphologically diverse bacteria belonging to this large phylum based on a limited number of features has proved to be difficult, not least when taxonomic decisions rested heavily on interpretation of poorly resolved 16S rRNA gene trees. Here, draft genome sequences of a large collection of actinobacterial type strains were used to infer phylogenetic trees from genome-scale data using principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families, and genera, as well as many species and a few subspecies were shown to be in need of revision leading to proposals for the recognition of 2 orders, 10 families, and 17 genera, as well as the transfer of over 100 species to other genera. In addition, emended descriptions are given for many species mainly involving the addition of data on genome size and DNA G+C content, the former can be considered to be a valuable taxonomic marker in actinobacterial systematics. Many of the incongruities detected when the results of the present study were compared with existing classifications had been recognized from 16S rRNA gene trees though whole-genome phylogenies proved to be much better resolved. The few significant incongruities found between 16S/23S rRNA and whole genome trees underline the pitfalls inherent in phylogenies based upon single gene sequences. Similarly good congruence was found between the discontinuous distribution of phenotypic properties and taxa delineated in the phylogenetic trees though diverse non-monophyletic taxa appeared to be based on the use of plesiomorphic character states as diagnostic features.

Diversity and Applications of Endophytic Actinobacteria of Plants in Special and Other Ecological Niches

Actinobacteria are wide spread in nature and represent the largest taxonomic group within the domain Bacteria. They are abundant in soil and have been extensively explored for their therapeutic applications. This versatile group of bacteria has adapted to diverse ecological habitats, which has drawn considerable attention of the scientific community in recent times as it has opened up new possibilities for novel metabolites that may help in solving some of the most challenging problems of the day, for example, novel drugs for drug-resistant human pathogens, affordable means to maintain ecological balance in various habitats, and alternative practices for sustainable agriculture. Traditionally, free dwelling soil actinobacteria have been the subject of intensive research. Of late, symbiotic actinobacteria residing as endophytes within the plant tissues have generated immense interest as potential source of novel compounds, which may find applications in medicine, agriculture, and environment. In the light of these possibilities, this review focuses on the diversity of endophytic actinobacteria isolated from the plants of extreme habitats and specific ecological niches. Furthermore, an attempt has been made to assign chemical class to the compounds obtained from endophytic actinobacteria. Potential therapeutic applications of these compounds and the utility of endophytic actinobacteria in agriculture and environment are discussed.

Nonomuraea rhizosphaerae sp. nov., an actinomycete isolated from the rhizosphere soil of a rubber tree (Hevea brasiliensis Muell. Arg)

A novel actinomycete, designated strain NEAU-mq18^T, was isolated from the rhizosphere soil of a rubber tree (Hevea brasiliensis Muell. Arg) collected from Xianglu Mountain in Heilongjiang Province, northeast China, and subjected to a polyphasic taxonomic study. The 16S rRNA gene sequence analysis showed that the isolate belongs to the genus Nonomuraea with high sequence similarity to Nonomuraea guangzhouensis NEAU-ZJ3^T (98.5%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain clusters phylogenetically with N. guangzhouensis NEAU-ZJ3^T and Nonomuraea glycinis NEAU-BB2C19^T. Moreover, key chemotaxonomic properties including the major menaquinones, fatty acid composition and phospholipid profile also confirmed the affiliation of the strain to the genus Nonomuraea. However, some physiological, morphological and biochemical properties, and low DNA-DNA relatedness values, enabled the strain to be differentiated from closely related species of the genus Nonomuraea. Thus, strain NEAU-mq18^T is concluded to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea rhizosphaerae sp. nov. is proposed. The type strain is NEAU-mq18^T (=CGMCC 4.7431^T=DSM 105761^T).

Nonomuraea lycopersici sp. nov., isolated from the root of tomato plants (Solanum lycopersicum L.)

Two novel bacterial strains were isolated from the roots of tomato plants (Solanum lycopersicum L.) from Dengfeng, Henan Province, China. Phylogenetic analysis of 16S rRNA gene sequences showed that the isolates NEAU-DE8(1)^T and NEAU-HE1(2) are closely related to one another (99.6% similarity) and are closely relate to Nonomuraea zeae NEAU-ND5^T (98.3, 98.3%) and Nonomuraea gerenzanensis DSM 100948^T (98.3, 98.0%). Phylogenetic trees constructed based on 16S rRNA gene sequences revealed that both strains grouped with N. zeae NEAU-ND5^T within the clade comprising the members of the genus Nonomuraea. Moreover, key chemotaxonomic properties including major menaquinones, fatty acid composition and phospholipid profiles also confirmed the affiliation of the two strains to the genus Nonomuraea. However, DNA-DNA hybridization data, together with physiological and morphological properties, showed that two isolates could be readily distinguished from their close phylogenetic relatives. Thus, on the basis of these phenotypic and genotypic data, strains NEAU-DE8(1)^T and NEAU-HE1(2) are concluded to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea lycopersici sp. nov. is proposed. The type strain is NEAU-DE8(1)^T (= CGMCC 4.7412^T = DSM 104642^T).

Nonomuraea glycinis sp. nov., a novel actinomycete isolated from the root of black soya bean [Glycine max (L.) Merr]

A novel actinomycete, designated strain NEAU-BB2C19T, was isolated from the root of black soya bean [Glycine max (L.) Merr] collected from Harbin, Heilongjiang Province, China, and characterized using a polyphasic approach. The strain was an aerobic, Gram-stain-positive actinomycete that formed extensively branched substrate mycelium and aerial hyphae. The predominant menaquinones were MK-9(H2) and MK-9(H0). The major cellular fatty acid profile consisted of iso-C16 : 0, 10-methyl C17 : 0 and 10-methyl C18 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, phosphatidylglycerol and glycolipid. The DNA G+C content was 68.2±0.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-BB2C19T should be assigned to the genus Nonomuraea and formed a distinct branch with its closest neighbour Nonomuraea guangzhouensis NEAU-ZJ3T (98.75 % 16S rRNA gene sequence similarity). The morphological and chemotaxonomic properties of the strain were also consistent with those of members of the genus Nonomuraea. A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-BB2C19T could be clearly differentiated from its closest phylogenetic relative. Thus, the strain is concluded to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea glycinis sp. nov. is proposed. The type strain is NEAU-BB2C19T (=CGMCC 4.7430T=DSM 104838T).

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).

Classification of Nonomuraea sp. ATCC 39727, an actinomycete that produces the glycopeptide antibiotic A40926, as Nonomuraea gerenzanensis sp. nov

Strain ATCC 39727, which produces the antibiotic A40926 (the natural precursor of the antibiotic dalbavancin), was isolated from a soil sample collected in India, and it was originally classified as a member of the genus Actinomadura on the base of morphology and cell-wall composition. A phylogenetic analysis based on 16S rRNA gene sequences indicates that the strain forms a distinct clade within the genus Nonomuraea, and it is most closely related to Nonomuraea angiospora DSM 43173T (98.72 % similarity) and Nonomuraea jabiensis A4036T (98.69 %). The strain forms an extensively branched substrate mycelium and aerial hyphae that form spiral chains of spores with ridged surfaces. The cell wall contains meso-diaminopimelic acid and the whole-cell sugars are glucose, ribose, galactose, mannose and madurose (madurose as the diagnostic sugar). The N-acyl type of muramic acid is acetyl. The predominant menaquinone is MK-9(H4), with minor amounts of MK-9(H2), MK-9(H6) and MK-9(H0). The polar-lipid profile includes diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylmethylethanolamine, hydroxyphosphatidylmethylethanolamine, phosphatidylinositol and a series of uncharacterized phospholipids, glycolipids and phosphoglycolipids. The major cellular fatty acids are iso-C16 : 0 and 10-methyl C17 : 0. The genomic DNA G+C content is 71.2 mol%. Significant differences in the morphological, chemotaxonomic and biochemical data, together with DNA-DNA relatedness between strain ATCC 39727 and closely related type strains, clearly demonstrated that strain ATCC 39727 represents a novel species of the genus Nonomuraea, for which the name Nonomuraea gerenzanensis sp. nov. is proposed. The type strain is ATCC 39727T ( = DSM 100948T).

Nonomuraea purpurea sp. nov., an actinomycete isolated from mangrove sediment

A polyphasic approach was used to verify the novel actinomycete, strain 1SM4-01T, isolated from mangrove sediment collected from Ranong Province, Thailand. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the organism was a member of the genus Nonomuraea and was most closely related to Nonomuraea syzygii GKU 164T (98.7 % sequence similarity), Nonomuraea rhizophila YIM 67092T (98.4 %), Nonomuraea solani NEAU-Z6T (98.4 %), Nonomuraea monospora PT708T (98.3 %) and Nonomuraea thailandensis KC-061T (98.2 %). The strain produced branching aerial mycelium which differentiated into straight chains of rough-surfaced spores borne at the end of a short sporophore. The whole-cell hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid, with madurose, mannose and ribose as the main sugars. MK-9(H4) was a major menaquinone of this strain. The acyl type of peptidoglycan was N-acetyl. The predominant cellular fatty acids were C17 : 1ω8c and iso-C16 : 0. Phospholipids consisted of diphosphatidylglycerol, hydroxy-phosphatidylethanolamine, hydroxy-phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, aminophospholipids and unidentified lipids. The G+C content of the genomic DNA was 70.4 mol%. On the basis of phenotypic characteristics, DNA-DNA relatedness and phylogenetic distinctiveness, strain 1SM4-01T represents a novel species of the genus Nonomuraea, for which the name Nonomuraea purpurea sp. nov. is proposed. The type strain is 1SM4-01T (=BCC 60397T=NBRC 109647T).

Streptomyces bryophytorum sp. nov., an endophytic actinomycete isolated from moss (Bryophyta)

A novel endophytic actinomycete, designated strain NEAU-HZ10(T) was isolated from moss and characterised using a polyphasic approach. The strain was found to have morphological and chemotaxonomic characteristics typical of the genus Streptomyces. Strain NEAU-HZ10(T) formed grayish aerial mycelia, which differentiated into straight to flexuous chains of cylindrical spores. The cell wall peptidoglycan was found to contain LL-diaminopimelic acid. Predominant menaquinones were identified as MK-9(H6) and MK-9(H8). The polar lipid profile was found to consist of phosphatidylethanolamine, phosphatidylinositol and two unidentified phospholipids. The major fatty acids were identified as iso-C16:0, anteiso-C15:0 and C16:0. 16S rRNA gene sequence similarity studies showed that strain NEAU-HZ10(T) belongs to the genus Streptomyces and exhibits high sequence similarity to Streptomyces cocklensis DSM 42063(T) (98.9 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-HZ10(T) clustered with S. cocklensis DSM 42063(T), Streptomyces yeochonensis CGMCC 4.1882(T) (98.7 %), Streptomyces paucisporeus CGMCC 4.2025(T) (98.4 %) and Streptomyces yanglinensis CGMCC 4.2023(T) (98.1 %). However, a combination of DNA-DNA hybridisation results and some phenotypic characteristics indicated that strain NEAU-HZ10(T) can be distinguished from its phylogenetically closely related strains. Therefore, it is proposed that strain NEAU-HZ10(T) represents a novel species of the genus Streptomyces for which the name Streptomyces bryophytorum sp. nov. is proposed. The type strain is NEAU-HZ10(T) (= CGMCC 4.7151(T) = DSM 42138(T)).

Streptosporangium jiaoheense sp. nov. and Streptosporangium taraxaci sp. nov., actinobacteria isolated from soil and dandelion root (Taraxacum mongolicum Hand.-Mazz.)

Two novel actinobacteria, designated strains NEAU-Jh1-4T and NEAU-Wp2-0T, were isolated from muddy soil collected from a riverbank in Jiaohe and a dandelion root collected from Harbin, respectively. A polyphasic study was carried out to establish the taxonomic positions of these two strains. The phylogenetic analysis based on the 16S rRNA gene sequences of strains NEAU-Jh1-4T and NEAU-Wp2-0T indicated that strain NEAU-Jh1-4T clustered with Streptosporangium nanhuense NEAU-NH11T (99.32 % 16S rRNA gene sequence similarity), Streptosporangium purpuratum CY-15110T (98.30 %) and Streptosporangium yunnanense CY-11007T (97.95 %) and strain NEAU-Wp2-0T clustered with 'Streptosporangium sonchi  ' NEAU-QS7 (99.39 %), 'Streptosporangium kronopolitis' NEAU-ML10 (99.26 %), 'Streptosporangium shengliense' NEAU-GH7 (98.85 %) and Streptosporangium longisporum DSM 43180T (98.69 %). Moreover, morphological and chemotaxonomic properties of the two isolates also confirmed their affiliation to the genus Streptosporangium. However, the low level of DNA-DNA hybridization and some phenotypic characteristics allowed the isolates to be differentiated from the most closely related species. Therefore, it is proposed that strains NEAU-Jh1-4T and NEAU-Wp2-0T represent two novel species of the genus Streptosporangium, for which the name Streptosporangium jiaoheense sp. nov. and Streptosporangium taraxaci sp. nov. are proposed. The type strains are NEAU-Jh1-4T (=CGMCC 4.7213T=JCM 30348T) and NEAU-Wp2-0T (=CGMCC 4.7217T=JCM 30349T), respectively.

Streptomyces polygonati sp. nov., an endophytic actinomycete isolated from a root of Polygonatum odoratum (Mill.)

A novel actinomycete, designated strain NEAU-G9^T, was isolated from the root of Polygonatum odoratum (Mill.) collected from Harbin, Heilongjiang province, north China, and was characterized using a polyphasic approach. Key morphological and chemotaxonomic properties confirmed the affiliation of strain NEAU-G9^T to the genus Streptomyces. Strain NEAU-G9^T contained ll-diaminopimelic acid as the diamino acid. The predominant menaquinones were MK-9(H₈), MK-9(H₆) and MK-9(H₄). The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The predominant fatty acids were iso-C_16 : 0, anteiso-C_15 : 0 and C_16 : 0.16S rRNA gene sequence similarity studies showed that strain NEAU-G9^T belongs to the genus Streptomyces and exhibits the highest sequence similarity to Streptomyces yanglinensis JCM 13275^T (97.75 %). However, phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-G9^T is most closely related to Streptomyces misakiensis JCM 4062^T (97.12 % sequence similarity). A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-G9^T can be clearly distinguished from S. yanglinensis JCM 13275^T and S. misakiensis JCM 4062^T. Consequently, strain NEAU-G9^T represents a novel species of the genus Streptomyces, for which the name Streptomyces polygonati sp. nov. is proposed. The type strain is NEAU-G9^T ( = CGMCC 4.7237^T = DSM 100521^T).

Continuing hunt for endophytic actinomycetes as a source of novel biologically active metabolites

Drug-resistant pathogens and persistent agrochemicals mount the detrimental threats against human health and welfare. Exploitation of beneficial microorganisms and their metabolic inventions is most promising way to tackle these two problems. Since the successive discoveries of penicillin and streptomycin in 1940s, numerous biologically active metabolites have been discovered from different microorganisms, especially actinomycetes. In recent years, actinomycetes that inhabit unexplored environments have received significant attention due to their broad diversity and distinctive metabolic potential with medical, agricultural and industrial importance. In this scenario, endophytic actinomycetes that inhabit living tissues of plants are emerging as a potential source of novel bioactive compounds for the discovery of drug leads. Also, endophytic actinomycetes are considered as bio-inoculants to improve crop performance through organic farming practices. Further efforts on exploring the endophytic actinomycetes associated with the plants warrant the likelihood of discovering new taxa and their metabolites with novel chemical structures and biotechnological importance. This mini-review highlights the recent achievements in isolation of endophytic actinomycetes and an assortment of bioactive compounds.

Actinoallomurus bryophytorum sp. nov., an endophytic actinomycete isolated from moss (Bryophyta)

A novel endophytic actinomycete, strain NEAU-TX1-15(T), was isolated from moss, collected from Wuchang, Heilongjiang province, north China. A polyphasic taxonomic study was carried out to establish the status of strain NEAU-TX1-15(T). Morphological and chemotaxonomic properties of strain NEAU-TX1-15(T) are consistent with the description of the genus Actinoallomurus. Strain NEAU-TX1-15(T) was observed to form short spiral or looped spore chains on aerial hyphae. The cell wall peptidoglycan was found to contain lysine and meso-diaminopimelic acid. The major menaquinones were identified as MK-9(H6) and MK-9(H8). The only phospholipid identified was phosphatidylglycerol. The major fatty acid was identified as iso-C16:0. Analysis of the 16S rRNA gene sequence supports the assignment of the novel strain to the genus Actinoallomurus, as it exhibits 99.2 % gene sequence similarity to that of Actinoallomurus yoronensis NBRC 103686(T). However, the low level of DNA-DNA relatedness allowed the strain to be differentiated from its close relative. Moreover, strain NEAU-TX1-15(T) could also be differentiated from A. yoronensis NBRC 103686(T) and other Actinoallomurus species showing high 16S rRNA gene sequence similarity (>98.0 %) by cultural and physiological characteristics. Therefore, the combination of phenotypic and chemotaxonomic data, and the DNA-DNA hybridization value, indicated that strain NEAU-TX1-15(T) represents a novel species of the genus Actinoallomurus for which the name Actinoallomurus bryophytorum sp. nov. is proposed. The type strain is NEAU-TX1-15(T) (=CGMCC 4.7200(T) = JCM 30340(T)).

Sphaerisporangium corydalis sp. nov., isolated from the root of Corydalis yanhusuo L

Two Gram-stain positive, aerobic actinomycete strains, designated NEAU-YHS12 and NEAU-YHS15(T), were isolated from the root of Corydalis yanhusuo L. collected from Wuchang, Heilongjiang Province, northeast China. Phylogenetic analysis of 16S rRNA gene sequences showed that the two strains are closely related to one another (99.8 % similarity), and had the closest relationship with Sphaerisporangium cinnabarinum JCM 3291(T) (98.7, 98.6 %), Sphaerisporangium flaviroseum YIM 48771(T) (98.6, 98.6 %), Sphaerisporangium melleum JCM 13064(T) (98.5, 98.4 %) and Sphaerisporangium dianthi NEAU-CY18(T) (98.4, 98.4 %). DNA-DNA hybridization value between strains NEAU-YHS12 and NEAU-YHS15(T) was 82 ± 1.4 %, and the values between the two strains and the closely related type strains were well below 70 %. The two strains also shared a number of phenotypic characteristics that were distinct from the closely related species. Both strains were observed to contain MK-9(H6), MK-9(H4) and MK-9(H2) as the detected menaquinones. The cell wall peptidoglycan was found to contain meso-diaminopimelic acid. The phospholipid profiles were found to contain diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, phosphoglycolipid, and an unidentified phospholipid. The major fatty acids were identified as iso-C16:0, C17:1 ω7c, C18:0 and iso-C15:0. On the basis of the genetic and phenotypic properties, it is proposed that strains NEAU-YHS15(T) and NEAU-YHS12 be classified as representatives of a novel species of the genus Sphaerisporangium, for which the name Sphaerisporangium corydalis sp. nov is proposed. The type strain is NEAU-YHS15(T) (CGMCC 4.7148(T) = DSM46732(T)).

Microbispora bryophytorum sp. nov., an actinomycete isolated from moss (Bryophyta)

A novel endophytic actinomycete, designated strain NEAU-TX2-2T, was isolated from moss and characterized using a polyphasic approach. The isolate was found to have morphological characteristics typical of the genus Microbispora . The isolate formed longitudinally paired spores on the tips of short sporophores that branched from aerial hyphae. Analysis of the 16S rRNA gene sequence supported the assignment of the novel strain to the genus Microbispora , and strain NEAU-TX2-2T exhibited 99.08 and 98.62 % gene sequence similarities to Microbispora amethystogenes JCM 3021T and Microbispora rosea subsp. rosea JCM 3006T, respectively. However two tree-making algorithms supported the position that strain NEAU-TX2-2T formed a distinct clade with M. rosea subsp. rosea JCM 3006T. A low level of DNA–DNA relatedness allowed the isolate to be differentiated from M. amethystogenes JCM 3021T and M. rosea subsp. rosea JCM 3006T. Moreover, strain NEAU-TX2-2T could also be distinguished from its closest phylogenetic relatives by morphological and physiological characteristics. Therefore, it is proposed that strain NEAU-TX2-2T represents a novel species of the genus Microbispora for which the name Microbispora bryophytorum sp. nov. is proposed. The type strain is NEAU-TX2-2T ( = CGMCC 4.7138T = DSM 46710T).

Nonomuraea syzygii sp. nov., an endophytic actinomycete isolated from the roots of a jambolan plum tree (Syzygium cumini L. Skeels)

A novel endophytic actinomycete, designated strain GKU 164T, was isolated from the roots of a jambolan plum tree (Syzygium cumini L. Skeels), collected at Khao Khitchakut National Park, Chantaburi province, Thailand. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain formed a distinct clade within the genus Nonomuraea , and was most closely related to Nonomuraea monospora PT708T (98.77 % 16S rRNA gene sequence similarity) and Nonomuraea thailandensis KC-061T (98.73 %). Strain GKU 164T formed a branched substrate and aerial hyphae that generated single spores with rough surfaces. The cell wall contained meso-diaminopimelic acid. The whole-cell sugars were madurose, galactose, mannose, ribose, rhamnose and glucose. The N-acyl type of muramic acid was acetyl. The predominant menaquinone was MK-9(H4) with minor amounts of MK-9(H6), MK-9(H2) and MK-9(H0). The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannosides, phosphatidylmonomethylethanolamine, hydroxy-phosphatidylmonomethylethanolamine, an unidentified aminophosphoglycolipid and four unknown phospholipids. The major fatty acids were iso-C16 : 0 and 10-methyl C17 : 0. The genomic DNA G+C content was 70.4 mol%. Significant differences in the morphological, chemotaxonomical, and biochemical data together with DNA–DNA relatedness values between strain GKU 164T and type strains of closely related species, clearly demonstrated that strain GKU 164T represents a novel species of the genus Nonomuraea , for which the name Nonomuraea syzygii sp. nov. is proposed. The type strain is GKU 164T ( = BCC 70457T = NBRC 110400T).

Saccharothrix carnea sp. nov., an actinobacterium isolated from soil

A novel actinobacterium, designated strain NEAU-yn17T, was isolated from a soil sample collected at the wastewater discharge site of a pesticide factory in Harbin, northern China, and characterized using a polyphasic approach. Morphological and chemotaxonomic properties of strain NEAU-yn17T were consistent with the description of the genus Saccharothrix , such as the spore arrangement, the diamino acid of the peptidoglycan, the whole-cell hydrolysates, the predominant menaquinone and the phospholipid profile. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain NEAU-yn17T should also be classified in the genus Saccharothrix , with Saccharothrix saharensis DSM 45456T (99.52 % sequence similarity) and Saccharothrix xinjiangensis JCM 12329T (99.04 %) as the nearest phylogenetic relatives. A combination of DNA–DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-yn17T can be distinguished from its closest relatives. Therefore, strain NEAU-yn17T represents a novel species of the genus Saccharothrix , for which the name Saccharothrix carnea sp. nov. is proposed. The type strain is NEAU-yn17T ( = CGMCC 4.7097T = DSM 45878T).

Sphaerisporangium dianthi sp. nov., an endophytic actinomycete isolated from a root of Dianthus chinensis L

A novel actinomycete, designated strain NEAU-CY18(T), was isolated from the root of a Chinese medicinal plant Dianthus chinensis L and subjected to a polyphasic taxonomic study. The novel strain was found to develop spherical sporangia with non-motile spores on aerial mycelium. The cell-wall peptidoglycan was found to contain meso-diaminopimelic acid. The whole-cell sugars were identified as madurose, mannose, ribose, galactose and glucose. The phospholipid profile was found to contain diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylmethylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides and an unidentified phospholipid. The predominant menaquinones were identified as MK-9(H4), MK-9(H2) and MK-9(H6). The major fatty acids were identified as C17:0 10-methyl, iso-C16:0 and C16:0. EzTaxon-e analysis of the 16S rRNA gene sequence indicated that the strain belongs to the genus Sphaerisporangium and was most closely related to Sphaerisporangium cinnabarinum JCM 3291(T) (98.9 %) and Sphaerisporangium melleum JCM 13064(T) (98.3 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-CY18(T) forms a monophyletic clade with S. cinnabarinum JCM 3291(T), an association that was supported by a bootstrap value of 97 % in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. Comparisons of some phenotypic properties and low DNA-DNA relatedness values enabled the strain to be differentiated from S. cinnabarinum JCM 3291(T) and S. melleum JCM 13064(T). Therefore, it is concluded that strain NEAU-CY18(T) represents a novel Sphaerisporangium species, for which the name Sphaerisporangium dianthi sp. nov. is proposed. The type strain is NEAU-CY18(T) ( = CGMCC 4.7132(T) = DSM 46736(T)).

The genus Nonomuraea: A review of a rare actinomycete taxon for novel metabolites

The genus Nonomuraea is a rare actinomycete taxon with a long taxonomic history, while its generic description was recently emended. The genus is less known among the rare actinomycete genera as its taxonomic position was revised several times. It can be found in diverse ecological niches, while most of its member species were isolated from soil samples. However, new trends to discover the genus in other habitats are increasing. Generic abundance of the genus was found to be dependent on geographical changes. Novel sources together with selective and invented isolation techniques might increase a chance to explore the genus and its novel candidates. Interestingly, some of its members have been revealed as a valuable source of novel metabolites for medical and industrial purposes. Broad-range of potent bioactive compounds including antimicrobial, anticancer, and antipsychotic substances, broad-spectrum antibiotics and biocatalysts can be synthesized by the genus. In order to investigate biosynthetic pathways of the bioactive compounds and self-resistant mechanisms to these compounds, the links from genes to metabolites have yet been needed for further discovery and biotechnological development of the genus Nonomuraea.

Nonomuraea guangzhouensis sp. nov., and Nonomuraea harbinensis sp. nov., two novel actinomycetes isolated from soil

Two novel actinomycetes, designated strains NEAU-ZJ3(T) and NEAU-yn31(T), were isolated from soils in China and their taxonomic positions determined by a polyphasic approach. Key morphological and chemotaxonomic properties of the two strains were consistent with the description of the genus Nonomuraea. The G+C contents of strains NEAU-ZJ3(T) and NEAU-yn31(T) were determined to be 67.4 and 68.0 %, respectively. Phylogenetic analysis using 16S rRNA gene sequences indicated that the two strains should be classified in the genus Nonomuraea. The 16S rRNA gene sequence of strain NEAU-ZJ3(T) showed it to be most closely related to Nonomuraea salmonea DSM 43678(T) (98.27 %), Nonomuraea endophytica YIM 65601(T) (98.23 %) and Nonomuraea candida HMC10(T) (98.08 %), and that of strain NEAU-yn31(T) to Nonomuraea ferruginea IFO 14094(T) (99.08 %) and N. candida HMC10(T) (98.01 %). Furthermore, a combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that the two strains can be distinguished from each other and their phylogenetically closest relatives. Thus, strains NEAU-ZJ3(T) and NEAU-yn31(T) represent two novel species of the genus Nonomuraea, for which the names Nonomuraea guangzhouensis sp. nov. and Nonomuraea harbinensis sp. nov. are proposed. The type strains are NEAU-ZJ3(T) (=CGMCC 4.7101(T) = DSM 45889(T)) and NEAU-yn31(T) (=CGMCC 4.7106(T) = DSM 45887(T)), respectively.