A simple HPLC method for analysing diaminopimelic acid diastereomers in cell walls of Gram-positive bacteria

Glycomyces niveus sp. nov., a novel actinomycete isolated from sandy soil

A novel mycelium-forming actinomycete, designated strain NEAU-S30T, was isolated from the sandy soil of a sea beach in Shouguang city, Shandong province, PR China. The strain developed long chains of non-motile cylindrical spores with smooth surfaces on aerial mycelia. The results of a polyphasic taxonomic study indicated that NEAU-S30T represented a member of the genus Glycomyces. The results of 16S rRNA gene sequence analysis indicated that NEAU-S30T was closely related to 'Glycomycesluteolus' (98.97 % sequence similarity), Glycomycesalgeriensis (98.90 %), 'Glycomyces tritici' (98.83 %) and Glycomyces lechevalierae (98.76 %). The average nucleotide identity (ANI) values between NEAU-S30T and 'G. luteolus' NEAU-A15, G. algeriensis DSM 44727T, 'G. tritici' NEAU-C2 and G. lechevalierae DSM 44724T were 87.77, 87.53, 87.41 and 87.80 %, respectively. The digital DNA G+C content of the genomic DNA was 70.5 %. The whole-cell sugars contained ribose and xylose. The predominant menaquinones were MK-10(H2), MK-10(H4) and MK-10(H6). The predominant fatty acids were anteiso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and iso-C15 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified glycolipid. On the basis of the results of comparative analysis of genotypic, phenotypic and chemotaxonomic data, the novel actinomycete strain NEAU-S30T (=JCM 33975T=CGMCC 4.7890T) represents the type strain of a novel species within the genus Glycomyces, for which the name Glycomyces niveus sp. nov. is proposed.

Actinoplanes sandaracinus sp. nov., a novel ligninase- producing and cellulose-degrading actinobacterium isolated from soil

A novel ligninase-producing and cellulose-degrading actinobacterium, designated strain NEAU-A12T, was isolated from a soil sample collected from Aohan banner, Chifeng City, Inner Mongolia Autonomous Region, PR China. A polyphasic taxonomic study was used to establish the status of strain NEAU-A12T. 16S rRNA gene sequence analysis revealed that strain NEAU-A12T belonged to the genus Actinoplanes and showed the highest similarity (98.3 %) to Actinoplanes palleronii DSM 43940T, while showing less than 98.3 % similarity to other members of the genus Actinoplanes. The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and glycosylphosphatidylinositol. The diagnostic sugars in cell hydrolysates were determined to be arabinose, glucose and xylose. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were MK-9(H4), MK-9(H6) and MK-9(H2). The major fatty acids were C15 : 0, C16 : 0, C16 : 1  ω7c and C17 : 0. Meanwhile, genomic analysis revealed a genome size of 10 192 524 bp and a DNA G+C content of 70.6 mol%, and indicated that strain NEAU-A12T had the potential to degrade lignin and cellulose, as well as produce bioactive compounds. In addition, the average nucleotide identity values between strain NEAU-A12T and its reference strains A. palleronii DSM 43940T, Actinoplanes regularis DSM 43151T, Actinoplanes philippinensis DSM 43019T, Actinoplanes xinjiangensis DSM 45184T and Actinoplanes italicus DSM 43146T were 80.3, 80.3, 84.1, 84.3 and 84.0 %, respectively. The levels of digital DNA-DNA hybridization between them were found to be 23.6 % (21.3-26.1 %), 23.8 % (21.5-26.3 %), 28.3 % (25.9-30.8 %), 28.6 % (26.0-30.9 %) and 28.4 % (26.2-31.1 %), respectively. Based on phenotypic, chemotaxonomic and genotypic data, strain NEAU-A12T is considered to represent a novel species of the genus Actinoplanes, for which the name Actinoplanes sandaracinus sp. nov. is proposed, with NEAU-A12T (=CCTCC AA 2020039T=DSM 112043T) as the type strain.

Sinomonas cellulolyticus sp. nov., isolated from Loktak lake

A novel cellulolytic strain JC656T was isolated from the rhizosphere soil of Alisma plantago-aquatica of floating island (Phumdis) of Loktak lake, Manipur, India. The 16S rRNA gene sequence similarities between strain JC656T and other Sinomonas type strains ranged between 98.5 and 97.3%, wherein strain JC656T exhibited the highest sequence similarity (98.5%) to Sinomonas notoginsengisoli KCTC 29237T. Colonies were yellow-colored and grew aerobically. Cells were gram-positive, rod-shaped and non-motile. The optimal growth of the strain JC656T occured at 28 °C and pH 7. Strain JC656T contained MK-9 as the predominant isoprenoid quinone and anteiso-C15:0, iso-C16:0 and anteiso-C17:0 as the major fatty acids. Diphosphatidylglycerol, phosphatidylinositol, phosphatidylglycerol, phosphatidylmonomethylethanolamine and a glycolipid were the polar lipids. Strain JC656T contained lysine, alanine, glutamine, diaminopimelic acid (DAP) and two unidentified amino acids as characteristic cell wall amino acids. The genome size of strain JC656T was 3.9 Mb with a DNA G + C content of 69.9 mol %. For the affirmation of the strain's taxonomic status, a detailed phylogenomic study was done. Based on its phylogenetic position and morphological, physiological, and genomic features, strain JC656T represents a new species of the genus Sinomonas, for which we propose the name Sinomonas cellulolyticus sp. nov. The type strain JC656T = (KCTC 49339T = NBRC 114142T).

Acinetobacter oleivorans IRS14 alleviates cold stress in wheat by regulating physiological and biochemical factors

AIMS

Climate change is responsible for extreme cold winters, causing a significant loss in crop yield and productivity due to chilling stress. This study aims to investigate the potential of psychrotrophic plant growth-promoting rhizobacteria (PGPR) strain to promote wheat growth under cold stress and explore the adaptive responses of wheat.

METHODS AND RESULTS

Wheat seeds and seedlings were inoculated with the psychrotrophic strain IRS14 and the plants were cultivated for five weeks at 6°C ± 2°C. The genetic, biochemical, physiological, and molecular analysis of the bacterium and plant was done to evaluate the effect of the PGPR strain in alleviating chilling stress. IRS14 possesses antioxidant activity and produced multiple phytohormones, which enhanced seed germination (∼50%) and plant growth (∼50%) during chilling stress.

CONCLUSIONS

Here, we reported that the application of IRS14 helps to regulate the biochemical and metabolic pathways in wheat plants. It alleviates chilling stress and increases plant growth rate and biomass. Strain IRS14 in wheat effectively increased chlorophyll content, antioxidants, carotenoid, proline, and endogenous phytohormones compared with untreated wheat.

Comparative genomic analysis of Cohnella hashimotonis sp. nov. isolated from the International Space Station

A single strain from the family Paenibacillaceae was isolated from the wall behind the Waste Hygiene Compartment aboard the International Space Station (ISS) in April 2018, as part of the Microbial Tracking mission series. This strain was identified as a gram-positive, rod-shaped, oxidase-positive, catalase-negative motile bacterium in the genus Cohnella, designated as F6_2S_P_1T. The 16S sequence of the F6_2S_P_1T strain places it in a clade with C. rhizosphaerae and C. ginsengisoli, which were originally isolated from plant tissue or rhizosphere environments. The closest 16S and gyrB matches to strain F6_2S_P_1T are to C. rhizosphaerae with 98.84 and 93.99% sequence similarity, while a core single-copy gene phylogeny from all publicly available Cohnella genomes places it as more closely related to C. ginsengisoli. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values to any described Cohnella species are <89 and <22%, respectively. The major fatty acids for strain F6_2S_P_1T are anteiso-C15:0 (51.7%), iso-C16:0 (23.1%), and iso-C15:0 (10.5%), and it is able to metabolize a wide range of carbon compounds. Given the results of the ANI and dDDH analyses, this ISS strain is a novel species within the genus Cohnella for which we propose the name Cohnella hashimotonis, with the type strain F6_2S_P_1T (=NRRL B-65657T and DSMZ 115098T). Because no closely related Cohnella genomes were available, this study generated the whole-genome sequences (WGSs) of the type strains for C. rhizosphaerae and C. ginsengisoli. Phylogenetic and pangenomic analysis reveals that F6_2S_P_1T, C. rhizosphaerae, and C. ginsengisoli, along with two uncharacterized Cohnella strains, possess a shared set of 332 gene clusters which are not shared with any other WGS of Cohnella species, and form a distinct clade branching off from C. nanjingensis. Functional traits were predicted for the genomes of strain F6_2S_P_1T and other members of this clade.

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.

Saccharothrix luteola sp. nov., a novel cellulose-degrading actinobacterium isolated from soil and emended description of the genus Saccharothrix

A novel cellulose-degrading actinobacterium, designated strain NEAU-S10^T, was isolated from soil collected from Chifeng, Inner Mongolia Autonomous Region, PR China, and characterized using a polyphasic approach. Pairwise similarity of the 16S rRNA gene sequence showed that strain NEAU-S10^T was a representative of Saccharothrix and was closely related to Saccharothrix carnea NEAU-yn17^T (99.2 %), Saccharothrix saharensis SA152^T (99.0 %), Saccharothrix texasensis DSM 44231^T (98.5 %) and Saccharothrix xinjiangensis NBRC 101911^T (98.5 %). Physiological and chemotaxonomic characteristics of the strain further supported its affiliation to the genus Saccharothrix. The whole-cell sugars contained galactose, ribose and mannose. The polar lipids contained diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The predominant menaquinones were MK-9(H₀), MK-9(H₂), MK-9(H₄) and MK-10(H₄). The major fatty acids were iso-C_16 : 0, C_16 : 0, anteiso-C_17 : 0, iso-C_15 : 0 and iso-C_17 : 0. The genomic DNA G+C content was 71.8 mol%. The levels of digital DNA-DNA hybridization between isolate and S. carnea NEAU-yn17^T, S. saharensis SA152^T and S. texasensis DSM 44231^T were 40.1 % (37.6-42.6 %), 38.soap8 % (36.3-41.3 %) and 44.8 % (42.2-47.3 %) and the ANI values between them were determined to be 90.2, 89.8 and 91.7 %, the results indicated that strain NEAU-S10^T could be distinguished from its reference strains. The assembled genome sequence of strain NEAU-S10^T was found to be 10 305 394 bp long. The NCBI Prokaryotic Genome Annotation Pipeline (PGAP) revealed 8 994 protein-coding genes. Genomic analysis and Congo red staining test indicated that strain NEAU-S10^T had the potential to degrade cellulose. The genomic and phenotypic results indicate that strain NEAU-S10^T represents a novel species of the genus Saccharothrix, for which the name Saccharothrix luteola sp. nov. is proposed, with NEAU-S10^T (=CCTCC AA 2020037^T=JCM 34800^T) as the type strain.

Nocardia rosealba sp. nov., a novel ligninase-producing Actinobacterium isolated from soil

A novel ligninase-producing actinomycete, designated strain NEAU-G4T, was isolated from a soil sample and subjected to a polyphasic taxonomic study to establish its status. According to 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Nocardia , with the highest sequence similarity to Nocardia ignorata DSM 44496T (99.2 %). The whole-cell sugars contained galactose and arabinose. The amino acid of the cell wall was determined to be meso-diaminopimelic acid. The major fatty acids (>10 %) were C16 : 0, C18 : 1  ω9c, C18 : 0 and C16 : 1  ω7c. The predominant menaquinone was identified as MK-8(H6, ω-cycl). The major polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. Strain NEAU-G4T had a draft genome size of 6 405 167 bp, annotated with 5815 protein-coding genes. The DNA G+C content was 67.6 mol%. Phylogenetic analysis using the 16S rRNA gene and whole-genome sequences showed that strain NEAU-G4T formed a stable phyletic line with N. ignorata DSM 44496T. The digital DNA–DNA hybridization and average nucleotide identity values between them were 63.7 % (60.8–66.5 %) and 95.5 %, respectively. Moreover, genomic analysis indicated that strain NEAU-G4T had the potential to degrade lignin and produce bioactive compounds. On the basis of genotypic analysis, physiological data, as well as phenotypic and chemotaxonomic characterizations, it is concluded that the organism be classified as representing a novel species of the genus Nocardia , for which the name Nocardia rosealba sp. nov. is proposed. The type strain is NEAU-G4T (=CCTCC AA 2020038T=DSM 111936T).

Catellatospora tritici sp. nov., a novel cellulase-producing actinobacterium isolated from rhizosphere soil of wheat (Triticum aestivum L.) and emended description of the genus Catellatospora

A Gram-positive, cellulose-degrading actinobacterium, designed strain NEAU-YM18T, was isolated from rhizosphere soil of wheat (Triticum aestivum L.) sampled in Langfang, Hebei Province, PR China. The novel strain was characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics confirmed that strain NEAU-YM18T belonged to the genus Catellatospora . Cells of strain NEAU-YM18T were observed to contain meso- and 3-hydroxy-diaminopimelic acids as diagnostic cell-wall amino acids. The acyl type of the cell-wall muramic acid was glycolyl. The whole-cell hydrolysates were xylose, glucose and ribose. The phospholipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were iso-C15 : 0, iso-C16 : 0, C18 : 1  ω9c and summed feature 5 (anteiso-C18 : 0/C18 : 2  ω6,9c). The menaquinones were MK-9(H4), MK-9(H6) and MK-9(H2). The DNA G+C content was 71.1 %. The results of 16S rRNA gene sequence and phylogenetic analyses indicated that strain NEAU-YM18T was closely related to Catellatospora chokoriensis 2-25(1)T (98.4 % 16S rRNA gene sequence similarity), Catellatospora vulcania NEAU-JM1T (98.3%) and Catellatospora sichuanensis H14505T (98.3 %) and formed a branch with C. sichuanensis H14505T. Furthermore, the whole genome phylogeny of strain NEAU-YM18T showed that the strain formed an independent clade. The digital DNA–DNA hybridization results between NEAU-YM18T and C. chokoriensis 2-25(1)T, C. vulcania NEAU-JM1T and C. sichuanensis H14505T were 25.0, 24.7 and 24.7 %, respectively, and the whole-genome average nucleotide identity values between them were 81.5, 81.4 and 81.4 %, respectively. These genetic results and some phenotypic characteristics could distinguish strain NEAU-YM18T from its reference strains. In addition, genomic analysis confirmed that strain NEAU-YM18T had the potential to decompose cellulose and produce bioactive compounds. Therefore, strain NEAU-YM18T represents a novel species of the genus Catellatospora , for which the name Catellatospora tritici sp. nov. is proposed. The type strain is NEAU-YM18T (=CCTCC AA 2020040T=JCM 33977T).

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).

Nocardia albiluteola sp. nov., a novel lignin-degrading actinobacterium isolated from rhizosphere soil of pumpkin

A novel lignin-degrading actinobacterium, designated NEAU-G5T, was isolated from pumpkin rhizosphere soil collected from field in Mudanjiang, Heilongjiang Province, northeast China, and characterized using polyphasic approach. The prior 16S rRNA gene sequence similarities and phylogenic analysis showed that strain NEAU-G5T exhibited close phylogenetic relatedness to Nocardia miyunensis NBRC 108239T (98.82 %), Nocardia nova NBRC 15556T (98.75 %), Nocardia jiangxiensis NBRC 101359T (98.68 %) and Nocardia macrotermitis RB20T (98.61 %). Morphological and chemotaxonomic characteristics indicated that strain NEAU-G5T could be assigned to the genus Nocardia . The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, an unidentified phospholipid and an unidentified lipid. The predominant menaquinone was MK-8(H4, ω-cycl). The major fatty acids (>10 %) were identified as C16 : 0, C18 : 1  ω9c, 10-methyl C18 : 0 and C18 : 0. Mycolic acids were present. The genomic DNA G+C content of strain NEAU-G5T was 68 mol%. Moreover, based on digital DNA–DNA hybridization and average nucleotide identity values, strain NEAU-G5T could be differentiated from its reference strains. In addition, an azure B plate decolorization test and genomic analysis indicated that strain NEAU-G5T had the ability to degrade lignin. On the basis of polyphasic characteristics, strain NEAU-G5T represents a novel species of the genus Nocardia , with the name Nocardia albiluteola sp. nov. The type strain is NEAU-G5T (=CCTCC AA 2021018T=DSM 110547T).

Alicyclobacillus curvatus sp. nov. and Alicyclobacillus mengziensis sp. nov., two acidophilic bacteria isolated from acid mine drainage

Two acidophilic strains, designated as ALEF1^T and S30H14^T, were isolated from acid mine drainage sediment. Cells of both strains were Gram-stain-positive, aerobic, endospore-forming rods. Strains ALEF1^T and S30H14^T were acidophilic and mesophilic, the former grew at 20–40 °C (optimum, 30 °C) and pH 2.5–4.5 (optimum, pH 3.5), while the latter grew at 20–45 °C (optimum, 30 °C) and pH 2.0–5.5 (optimum, pH 4.5). The 16S rRNA gene-based sequence analysis revealed that strains ALEF1^T and S30H14^T belonged to the genus Alicyclobacillus, and were phylogenetically close to Alicyclobacillus ferrooxydans TC-34^T with 97.1 and 97.4% similarity, respectively. The similarity between the two novel strains was 98.6 %. The average nucleotide identity value between the genome sequences of ALEF1^T and S30H14^T was 79.5 %, and that between each of the two isolates and A. ferrooxydans TC-34^T were 72.0 and 74.3 %. In addition, the digital DNA–DNA hybridization value between ALEF1^T and S30H14^T was 24.9 %, between strain ALEF1^T and A. ferrooxydans TC-34^T was 21.7 %, and between S30H14^T and A. ferrooxydans TC-34^T was 26.3 %, far below the interspecies threshold. Both strains could utilize diverse carbon sources for heterotrophic growth; strain ALEF1^T could utilize ferrous iron as the energy source for autotrophic growth. Menaquinone 7 was the only quinone detected in either strain. Both strains contained anteiso-C_15 : 0 and anteiso-C_17 : 0, while ω-alicyclic fatty acids were not detected. Based on their phylogenetic positions, as well as phenotypic and genomic data, it is considered that strains ALEF1^T and S30H14^T represent two novel species within the genus Alicyclobacillus, for which the names Alicyclobacillus curvatus sp. nov. (type strain ALEF1^T=CGMCC 1.17055^T=KCTC 43124^T) and Alicyclobacillus mengziensis sp. nov. (S30H14^T=CGMCC 1.17050^T=KCTC 43125^T) are proposed.

Ruania rhizosphaerae sp. nov., a novel actinobacterium isolated from rhizosphere of Suaeda aralocaspica

A Gram-stain-positive, non-motile and short rod-shaped actinobacterium, designated strain LNNU 22110^T, was isolated from the rhizosphere soil of the halophyte Suaeda aralocaspica (Bunge) Freitag and Schütze, which collected in Xinjiang, north-west China. Growth occurred at 10-45 °C, pH 6.0-10.0 and in the presence of 0-11 % NaCl (w/v). Based on the results of 16S rRNA gene sequence phylogenetic analyses, strain LNNU 22110^T belonged to the genus Ruania and had 97.5 and 95.5 % sequence similarity to Ruania alba KCTC 19413^T and Ruania albidiflava CGMCC 4.3142^T, respectively. The digital DNA-DNA hybridization relatedness values between strain LNNU 22110^T and R. alba KCTC 19413^T and R. albidiflava CGMCC 4.3142^T were 23.2 and 19.9 %, respectively. The highest average nucleotide identity value between strain LNNU 22110^T and its closest related strain (R. alba KCTC 19413^T) was 80.2 %, much lower than the species delineation threshold of 95-96 %. The genome of strain LNNU 22110^T was 4.4 Mb, with a genomic DNA G+C content of 68.4 mol%. The diagnostic diamino acids in the peptidoglycan layer of strain LNNU 22110^T were lysine, alanine, glycine, glutamic acid and aspartic acid. The predominant menaquinone was MK-8(H₄). The major fatty acid (>10 %) was anteiso-C_15 : 0. The polar lipid profile of strain LNNU 22110^T included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, diacylated phosphatidyl dimannoside, one unidentified glycolipid and two unidentified phospholipids. According to the phenotypic, phylogenetic and chemotaxonomic results, strain LNNU 22110^T is considered to represent a novel species of the genus Ruania, for which the name Ruania rhizosphaerae sp. nov. is proposed. The type strain is LNNU 22110^T (=KCTC 39807^T=CGMCC 1.17105^T).

Streptomyces botrytidirepellens sp. nov., a novel actinomycete with antifungal activity against Botrytis cinerea

The fungal pathogen Botrytis cinerea is the causal agent of devastating gray mold diseases in many economically important fruits, vegetables, and flowers, leading to serious economic losses worldwide. In this study, a novel actinomycete NEAU-LD23^T exhibiting antifungal activity against B. cinerea was isolated, and its taxonomic position was evaluated using a polyphasic approach. Based on the genotypic, phenotypic and chemotaxonomic data, it is concluded that the strain represents a novel species within the genus Streptomyces, for which the name Streptomyces botrytidirepellens sp. nov. is proposed. The type strain is NEAU-LD23^T (=CCTCC AA 2019029^T=DSM 109824^T). In addition, strain NEAU-LD23^T showed a strong antagonistic effect against B. cinerea (82.6±2.5%) and varying degrees of inhibition on nine other phytopathogenic fungi. Both cell-free filtrate and methanol extract of mycelia of strain NEAU-LD23^T significantly inhibited mycelial growth of B. cinerea. To preliminarily explore the antifungal mechanisms, the genome of strain NEAU-LD23^T was sequenced and analyzed. AntiSMASH analysis led to the identification of several gene clusters responsible for the biosynthesis of bioactive secondary metabolites with antifungal activity, including 9-methylstreptimidone, echosides, anisomycin, coelichelin and desferrioxamine B. Overall, this research provided us an excellent strain with considerable potential to use for biological control of tomato gray mold.

Actinoplanes flavus sp. nov., a novel cellulase-producing actinobacterium isolated from coconut palm rhizosphere soil

A novel cellulase-producing actinomycete, designated strain NEAU-H7^T, was isolated from coconut palm rhizosphere soil collected from Wenchang City, Hainan Province, PR China. A polyphasic taxonomic study was carried out to establish the status of this strain. Results of 16S rRNA gene sequence analysis indicated that strain NEAU-H7^T belonged to the genus Actinoplanes, with highest similarity to Actinoplanes hulinensis NEAU-M9^T (99.2 % 16S rRNA gene sequence similarity). The diagnostic sugars in cell hydrolysates were determined to be ribose, galactose and mannose. The major fatty acids (>10%) were C_16 : 0, C_18 : 1  ω9c and C_18 : 0. The predominant menaquinones were identified as MK-9(H₄) and MK-9(H₆). The major polar lipids were phosphatidylethanolamine, phosphatidylinositol and two phosphatidylinositol mannosides. The amino acid of the cell-wall peptidoglycan was determined to be meso-diaminopimelic acid. The DNA G+C content was 71.2 mol%. Phylogenetic analysis using 16S rRNA gene sequences showed that strain NEAU-H7^T formed a stable phyletic line with A. hulinensis NEAU-M9^T. However, whole-genome phylogeny showed strain NEAU-H7^T formed a stable phyletic line with A. hulinensis NEAU-M9^T (99.2%), Actinoplanes campanulatus DSM 43148^T (98.6%), Actinoplanes capillaceus DSM 44859^T (98.3%) and Actinoplanes lobatus DSM 43150^T (97.6%). The digital DNA-DNA hybridization (dDDH) results between them were 53.6 (50.9-56.2), 54.1 (51.3-56.9), 53.1 (50.3-55.9) and 52.9 % (50.1-55.6 %), and whole-genome average nucleotide identity (ANI) values between them were 93.7, 93.6, 93.5 and 93.5 %. The low dDDH and ANI values demonstrated that strain NEAU-H7^T could be distinguished from its reference strains. Moreover, genomic analysis indicated that the strain NEAU-H7^T had the potential to decompose cellulose and produce bioactive compounds. On the basis of morphological, chemotaxonomic and phylogenetic characteristics, strain NEAU-H7^T is proposed to represent a novel species of the genus Actinoplanes, with the name Actinoplanes flavus sp. nov. The type strain is NEAU-H7^T (=CCTCC AA 2020034^T=DSM 112042^T).

Streptomyces luteolifulvus sp. nov., a novel actinomycete isolated from soil in Nanjing, China

During the investigation of exploring potential sources of novel species and natural bioactives, a novel actinomycete, designated strain HIT-DPA4^T, was isolated from a soil sample, which was collected from Nanjing, Jiangsu Province, PR China and characterized using a polyphasic approach. On the basis of 16S rRNA gene sequence similarities and the result of phylogenetic analysis, strain HIT-DPA4^T was most closely related to Streptomyces cyaneus CGMCC 4.1671 ^T, and shared the highest sequence similarity of 98.76%. In addition, the cell walls of the species HIT-DPA4^T contained LL-diaminopimelic acid as the diagnostic diamino acid and the whole-cell hydrolysates were identified as glucose and ribose, and the principal phospholipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside and phosphatidylmonomethylethanolamine. MK-9(H₆) and MK-9(H₄) were predominant menaquinones; and C_16:0, anteiso-C_15:0 and C_15:0 as major cellular fatty acids of the organism HIT-DPA4^T. Gene Ontology database analysis and antiSMASH server predicted results displayed that strain HIT-DPA4^T was a promising classification units, which has various types of functions and contains multiple biosynthetic gene clusters with the similarity more than 80%. Multilocus sequence analysis (MLSA) of five housekeeping genes (atpD, gyrB, recA, rpoB and trpB) illustrated that Streptomyces luteolifulvus formed a separate branch in the genus Streptomyces. However, a combination of low level of DNA-DNA relatedness and physiological properties indicated that strain HIT-DPA4^T can be distinguished from its phylogenetically related species Streptomyces cyaneus CGMCC 4.1671 ^T. Moreover, gene synteny research could be further differed organism HIT-DPA4^T from similarity species. Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces luteolifulvus sp. nov. is proposed. The type strain is HIT-DPA4^T (= CGMCC 4.7558 ^T = TISTR 2751 ^T).

Actinoplanes aureus sp. nov., a novel protease-producing actinobacterium isolated from soil

A novel protease-producing actinobacterium, designated strain NEAU-A11^T, was isolated from soil collected from Aohan banner, Chifeng, Inner Mongolia Autonomous Region, China, and characterised using a polyphasic approach. The hydrolytic enzymes, such as proteases, played critical roles in destruction of fungi by degrading the protein linkages to disrupt integrity in the cell wall. This suggested that the isolate could be a good biocontrol candidate against pathogens to control fungal diseases. On the basis of 16S rRNA gene sequence analysis, strain NEAU-A11^T was indicated to belong to the genus Actinoplanes and was most closely related to Actinoplanes rectilineatus JCM 3194 ^T (98.9%). Cell walls contained meso-diaminopimelic acid as the diagnostic diamino acid and the whole-cell sugars were arabinose, xylose and glucose. The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and two phosphatidylinositol mannosides. The predominant menaquinones were MK-9(H₄), MK-9(H₆) and MK-9(H₈). The major fatty acids were C_18:0, C_16:0, C_18:1 ω9c, C_17:0 and C_15:0. Genome sequencing revealed a genome size of 10,742,096 bp, a G + C content of 70.5% and 9,514 protein-coding genes (CDS), including 102 genes coding for protease. Moreover, Genome analysis showed that strain NEAU-A11^T contained 255 glycoside hydrolases (GHs), 152 glycosyl transferases (GTs), 40 carbohydrate esterases (CEs), 26 polysaccharide lyases (PLs), and 12 auxiliary activities (AAs) genes. Genome mining analysis using antiSMASH 5.0 led to the identification of 20 putative gene clusters responsible for the production of diverse secondary metabolites. Phylogenetic analysis using the 16S rRNA gene sequences showed that the strain formed a stable clade with A. rectilineatus JCM 3194 ^T in the genus Actinoplanes. Whole-genome phylogeny showed strain NEAU-A11^T formed a stable phyletic line with Actinoplanes lutulentus DSM 45883 ^T (97.6%). However, whole-genome average nucleotide identity value between strain NEAU-A11^T and its reference strains A. rectilineatus JCM 3194 ^T and A. lutulentus DSM 45883 ^T were found to be 81.1% and 81.6%, respectively. The levels of digital DNA-DNA hybridization between them were 24.6% (22.2-27.0%) and 24.8% (22.5-27.3%), respectively. The values were well below the criteria for species delineation of 70% for dDDH and 95-96% for ANI, suggesting that the isolate differed genetically from its closely related type strain. The content of G + C in genomic DNA was 70.5%, within the range of 67-76%. In addition, evidences from phenotypic, chemotaxonomic and genotypic studies indicated that strain NEAU-A11^T represents a novel species of the genus Actinoplanes, for which the name Actinoplanes aureus sp. nov. is proposed, with NEAU-A11^T (= CCTCC AA 2019063 ^T = JCM 33971 ^T) as the type strain.

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).

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 p1417^T, 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 p1417^T 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-C_16:0, anteiso-C_15:0, iso-C_15:0 and C_16:0. The genomic DNA G + C content of strain p1417^T based on the genome sequence was 72.0 mol%. Based on 16 S rRNA gene, five housekeeping genes and whole genome sequences analysis, strain p1417^T was most closely related to Streptomyces flavofungini JCM 4753^T (99.4% 16 S rRNA gene sequence similarity), Streptomyces alboflavus JCM 4615^T (98.8%) and Streptomyces aureoverticillatus JCM 4347^T (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 p1417^T and three closely related type strains. Therefore, it is concluded that strain p1417^T represents a novel species of the genus of Streptomyces, for which the name Streptomyces typhae sp. nov. is proposed. The type strain is p1417^T (= CCTCC AA 2019091^T = DSM 110636^T).

Lentzea alba sp. nov., a novel actinobacterium isolated from soil

A novel actinobacterium, designated strain NEAU-D13^T, was isolated from soil collected from Aohan Banner, Chifeng, Inner Mongolia Autonomous Region, China and characterized using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain NEAU-D13^T belonged to the genus Lentzea and shared the highest sequence similarity with Lentzea kentuckyensisJCM 14913^T (99.17 %). Morphological and chemotaxonomic characteristics of the strain also supported its assignment to the genus Lentzea. Cell walls contained meso-diaminopimelic acid as the diagnostic diamino acid and the whole-cell sugars were ribose and mannose. The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine and phosphatidylinositol. The menaquinone was only MK-9(H₄). The major fatty acids were iso-C_16:0, C_16:0, anteiso-C_17:0, iso-C_15:0 and anteiso-C_15:0. DNA G+C content was 68.71 mol%. Phylogenetic analysis using the 16S rRNA gene sequences showed that the strain formed a stable clade with L. kentuckyensisJCM 14913^T in the genus Lentzea. Meanwhile, a combination of digital DNA-DNA hybridization results and some phenotypic characteristics demonstrated that strain NEAU-D13^T could be distinguished from its closely related strain. Therefore, it is concluded that strain NEAU-D13^T represents a novel species of the genus Lentzea, for which the name Lentzea alba sp. nov. is proposed, with NEAU-D13^T (=CCTCC AA 2019089^T=JCM 33970^T) as the type strain.

Micromonospora rubida sp. nov., a novel actinobacterium isolated from soil of Harbin

A novel actinobacterium, designated strain NEAU-HG-1^T, was isolated from soil collected from Harbin, Heilongjiang Province, Northeast China and characterised using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain NEAU-HG-1^T belonged to the genus Micromonospora, and shared high sequence similarities with Micromonospora auratinigra DSM 44815^T (98.9%) and Micromonospora coerulea DSM 43143^T (98.7%). Morphological and chemotaxonomic characteristics of the strain also supported its assignment to the genus Micromonospora. Cell wall contained meso-diaminopimelic acid and the whole-cell sugars were arabinose and xylose. The polar lipid contained diphosphatidylglycerol, phosphatidylethanolamine, glycolipid and phosphatidylinositol. The predominant menaquinones were MK-10(H₂), MK-10(H₄) and MK-10(H₆). The major fatty acids were C_17:0 cycle, iso-C_15:0, and iso-C_16:0. Furthermore, strain NEAU-HG-1^T displayed a DNA-DNA relatedness of 33.8 ± 2.2% with M. coerulea DSM 43143^T. The level of digital DNA-DNA hybridization between strain NEAU-HG-1^T and M. auratinigra DSM 44815^T was 27.2% (24.8-29.7%). The value was well below the criteria for species delineation of 70% for dDDH. Whole-genome average nucleotide identity analyses result also indicated that the isolate should be assigned to a new species under the genus Micromonospora. Therefore, it is concluded that strain NEAU-HG-1^T represents a novel species of the genus Micromonospora, for which the name Micromonospora rubida sp. nov. is proposed, with NEAU-HG-1^T (= CGMCC 4.7479^T = JCM 32386^T) as the type strain.

Herbidospora solisilvae sp. nov., a novel cellulose-degrading actinobacterium isolated from forest soil

An aerobic, non-motile, Gram-stain positive, cellulose-degrading actinobacterium, designated strain NEAU-GS84^T, was isolated from a forest soil sample collected from Linchun Ridge Forest Park in Sanya, Hainan Province, China, and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics indicated that strain NEAU-GS84^T could belong to the genus Herbidospora. The 16S rRNA gene sequence analysis indeed confirmed that strain NEAU-GS84^T belonged to the genus Herbidospora and was most closely related to Herbidospora yilanensis JCM 18062^T (99.2% 16S rRNA gene sequence similarity) and Herbidospora galbida NEAU-GS14^T (99.0%). The cell wall of strain NEAU-GS84^T contained meso-diaminopimelic acid as the major diamino acid and the whole-cell hydrolysates mainly contained glucose, madurose and ribose. The major polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxyphosphatidylethanolamin, phosphoglycolipids, two phosphatidylinositol mannosides and one unidentified phospholipid. The predominant menaquinone was MK-10(H₄). Major fatty acids were 10-methly C_17:0, C_17:0 and iso-C_16:0. These chemotaxonomic data substantiated the affiliation of strain NEAU-GS84^T to the genus Herbidospora. The DNA G+C content was 70.7 mol%. The genome size of strain NEAU-GS84^T is about 8.37 Mb and contained 41 cellulose-binding domain synthesis genes, 13 β-glucosidase synthesis genes, 6 endoglucanase synthesis genes and 9 xylanase synthesis genes. Based on digital DNA-DNA hybridization and average nucleotide identity values, the new strain NEAU-GS84^T could be differentiated from its closest relatives. Therefore, the strain represents a novel species of the genus Herbidospora, for which the name Herbidospora solisilvae sp. nov. is proposed. The type strain is NEAU-GS84^T (= CCTCC AA 2018041^T = JCM 33460^T).

Actinomadura litoris sp. nov., an actinobacterium isolated from sandy soil in Sanya

A novel actinobacterium, designated strain NEAU-AAG5^T, was isolated from sandy soil collected from Niuwang island in Sanya, Hainan Province, PR China. The taxonomic position of the strain was investigated using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain NEAU-AAG5^T belongs to the genus Actinomadura and shared highest sequence similarity with Actinomadura macra NBRC 14102^T (98.8 %). Strain NEAU-AAG5^T grows at 20-40 °C (optimum, 28 °C), pH 6-10 (optimum, pH 7) and has NaCl tolerance of 0-3 %. The menaquinones were identified as MK-9(H₄) (4.2 %), MK-9(H₆) (49.2 %) and MK-9(H₈) (46.5 %). The major fatty acids were C_16 : 0 (31.4 %), 10-methyl C_18 : 0 (21.3 %) and C_18 : 1  ω9c (15.7 %). The polar lipids were diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannoside, phosphatidylglycerol and phosphoglycolipid. The genomic DNA G+C content of strain NEAU-AAG5^T based on whole genome sequences was 72.8 mol%. Digital DNA-DNA hybridization between strain NEAU-AAG5^T and its closest phylogenetic neighbour, A. macra NBRC 14102^T, resulted in similarity value of 28.0 % (<70 %). Additionally, the average nucleotide identity was 84.2 % for A. macra NBRC 14102^T. On the basis of phenotypic, genotypic and phylogenetic data, strain NEAU-AAG5^T can be characterized to represent a novel species of the genus Actinomadura, for which the name Actinomadura litoris sp. nov. is proposed. The type strain is NEAU-AAG5^T (=JCM 33456^T=CCTCC AA 2019043^T).

Nocardia bovistercoris sp. nov., an actinobacterium isolated from cow dung

A novel actinobacterium, designated strain NEAU-351^T, was isolated from cow dung collected from Shangzhi, Heilongjiang Province, northeast PR China and characterized using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-351^T belonged to the genus Nocardia, with the highest similarity (98.96 %) to Nocardia takedensis DSM 44801^T and less than 98.0 % identity with other type strains of the genus Nocardia. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major menaquinone was observed to contain MK-8(H₄, ω-cycl) (78.2 %). The fatty acid profile mainly consisted of C_16 : 0, C_18 : 1  ω9c and 10-methyl C_18 : 0. Mycolic acids were present. The genomic DNA G+C content of strain NEAU-351^T was 68.1 mol%. In addition, the average nucleotide identity values between strain NEAU-351^T and its reference strains, Nocardia takedensis DSM 44801^T and Nocardia arizonensis NBRC 108935^T, were found to be 81.4 and 82.9 %, respectively, and the level of digital DNA-DNA hybridization between them were 24.8 % (22.5-27.3 %) and 26.3 % (24-28.8 %), respectively. Here we report on the taxonomic characterization and classification of the isolate and propose that strain NEAU-351^T represents a new species of the genus Nocardia, for which the name Nocardia bovistercoris is proposed. The type strain is NEAU-351^T (=CCTCC AA 2019090^T=DSM 110681^T).

Microbispora sitophila sp. nov., a novel actinobacterium isolated from rhizosphere soil of wheat (Triticum aestivum L.)

A novel actinobacterium, designated strain NEAU-D428^T, was isolated from rhizosphere soil of wheat and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics of the strain coincided with members of the genus Microbispora. The 16S rRNA gene sequence analysis showed that the isolate was most closely related to Microbispora bryophytorum NEAU-TX2-2^T (99.2 %). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that the strain clustered with Microbispora clausenae CLES2^T (99.1 %), but formed a separate subclade in the phylogenomic tree within the genus Microbispora. The menaquinones were identified as MK-9(H₄), MK-9(H₂) and MK-9(H₀). The phospholipid profile was found to consist of diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, ninhydrin-positive glycophospholipid, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were identified as iso-C_16 : 0, C_16 : 0, 10-methyl C_17 : 0 and C_18 : 0. Digital DNA-DNA hybridization and average nucleotide identity values between strain NEAU-D428^T and M. bryophytorum NEAU-TX2-2^T, Microbispora camponoti 2C-HV3^T, M. clausenae CLES2^T, 'Microbispora cellulosiformans' Gxj-6^T and Microbispora fusca NEAU-HEGS1-5^T were 47.6 and 92.2 %, 47.5 and 92.2 %, 55.9 and 94.0 %, 33.1 and 86.8 %, and 33.6 and 87.1 %, respectively. These results and some physiological and biochemical properties demonstrated that the strain could be distinguished from its closest relatives. Therefore, it is proposed that strain NEAU-D428^T should be classified as representative of a novel species of the genus Microbispora, for which the name Microbispora sitophila sp. nov. is proposed. The type strain is NEAU-D428^T (=CGMCC 4.7523^T=DSM 109822^T).

Determination of γ-D-glutamyl-meso-diaminopimelic acid in rumen fluid of dairy cows by pre-column chiral derivatization-HPLC

High concentrate (HC) diet feeding leads to the lysis of rumen microbes and the release of hazardous metabolites, which can trigger inflammatory responses, thereby impairing dairy cow health and production. γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP), which constitutes the peptidoglycan (PGN) layer of bacteria, is the minimum PGN structure capable of activating inflammatory signaling pathways. This research paper aimed to determine the iE-DAP concentration and investigate the effects of an HC diet on the concentration of iE-DAP in the rumen fluid of dairy cows. However, there are limited studies on the determination of iE-DAP concentration. Hence, we established a high-performance liquid chromatography (HPLC) method combined with pre-column chiral derivatization to detect the concentration of iE-DAP in rumen fluid. Moreover, we conducted an animal experiment that included 12 lactating Holstein cows, which were randomly divided into a low-concentrate (LC) group and an HC group. The results showed that the linear range of iE-DAP was 5-500 µg/mL and that the intra- and inter-day RSDs were lower than 7%. Meanwhile, this method was successfully applied to the analysis of iE-DAP in rumen fluid, and the results revealed that long-term feeding with an HC diet elevated the concentration of iE-DAP in rumen fluid of dairy cows.

Enhancement of undecylprodigiosin production from marine endophytic recombinant strain Streptomyces sp. ALAA-R20 through low-cost induction strategy

Genetic manipulation of the undecylprodigiosin-producing strains and engineered culture medium approaches were applied as the most economical induction strategy for improving production. The hyper-producing recombinant strain ALAA-R20 was obtained after applying protoplast fusion strategy between the potent producer marine endophytic strains Streptomyces sp. ESRAA-10 (P1) and Streptomyces sp. ESRAA-31 (P2) of Dendronephthya hemprichi. Recombinant strain ALAA-R20 produced undecylprodigiosin yield higher than its parental strains ESRAA-10 and ESRAA-31 by 82.45% and 105.52% under submerged fermentation using modified R2YE medium. In order to reduce the costs of producing undecylprodigiosin, a solid-state fermentation (SSF) was applied. Scaled-up of optimized SSF parameters consisting of groundnut oil cake (GOC) sized to 3 mm, initial moisture content 80% with a mixture of dairy mill and fruit processing wastewaters (1:1), pH 7.0, inoculum size equal to 3 × 10⁵ spores/g dry substrate (gds), incubation temperature 30 °C, and 7-day incubation period yielded the highest yield of 181.78 mg/gds of undecylprodigiosin by the recombinant strain Streptomyces sp. ALAA-R20. Extraction and purification of the pigment using the chromatographic techniques as well as mass spectral analysis exhibited maximum absorbance at 539 nm which is physiological property of the undecylprodigiosin. Undecylprodigiosin was stable over a wide temperature ranged from - 20 to 35 °C even after storage for 6 months. The maximum yield and stability of pigment was obtained at the acidic pH (acidified methanol, pH 4.0). Undecylprodigiosin obtained from the recombinant strain Streptomyces sp. ALAA-R20 demonstrated strong antimicrobial activity against all multidrug-resistant bacterial and fungal strains tested with minimum inhibitory, minimum bactericidal, and minimum fungicidal concentrations ranged between 0.5 and 4.0, 0.5 to 4.0, and 1.0 to 8.0 μg/mL, respectively. It also showed complete inhibition of cancer cells; HCT-116, HepG-2, MCF-7 and A-549 at 5, 8, 4, and 7 μM with IC₅₀ equal to 2.0, 4.7, 1.2, and 2.8 μM, respectively.

Mesobacillus aurantius sp. nov., isolated from an orange-colored pond near a solar saltern

An endospore producing, strict aerobic, Gram-stain-positive, orange-colored colony forming bacterium designated as strain JC1013^T was isolated from an orange pond near a solar saltern of Tamil Nadu, India. Phylogenetic analysis of the 16S rRNA gene sequences indicated that strain was affiliated to the family Bacillaceae of the phylum Firmicutes. Strain showed highest 16S rRNA gene sequence identity of 98.7% with Mesobacillus selenatarsenatis SF-1 ^T and below 98.3% with other members of the genus Mesobacillus. Strain JC1013^T produced carotenoid pigments and indole compounds. Major cellular fatty acids of strain JC1013^T were iso-C_15:0, anteiso-C_15:0, C_16:0 3-OH, iso-C_17:0ω10c and summed feature 4 (iso-C_17:1 I/ anteisoB). Polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids and four unidentified phospholipids. Strain JC1013^T constituted m-diaminopimelic acid as diagnostic cell wall amino acids. MK-7 is the predominant menaquinone of strain JC1013^T. The genome size of strain JC1013^T was 4.6 Mbp and its G + C content was 42.7 mol%. For the affirmation of strain's taxonomic status, a detailed phylogenomic study was done. Based on the phylogenetic analyses, low ANI (84.6%), AAI (88.5%) values, in-silico DDH (< 29%) value, morphological, physiological and chemo-taxonomical characteristics, strain JC1013^T was clearly distinguished from the nearest phylogenetic neighbor, Mesobacillus selenatarsenatis SF-1^T to conclude that it is a new species of the genus Mesobacillus. We propose the name as Mesobacillus aurantius with type strain JC1013^T (= NBRC 114146^T = KACC 21451 ^T).

Characterization of a Novel Endophytic Actinomycete, Streptomyces physcomitrii sp. nov., and Its Biocontrol Potential Against Ralstonia solanacearum on Tomato

Bacterial wilt of tomato is a destructive disease caused by Ralstonia solanacearum throughout the world. An endophytic actinomycete with antagonistic activity, designated strain LD120^T, was isolated from moss (Physcomitrium sphaericum (Ludw) Fuernr). The biocontrol test demonstrated that co-inoculation by the isolate and the pathogen gave the greatest biocontrol efficiency of 63.6%. Strain LD120^T had morphological characteristics and chemotaxonomic properties identical to those of members of the genus Streptomyces. The diamino acid present in the cell wall was LL-diaminopimelic acid. Arabinose, glucose, rhamnose, and ribose occured in whole cell hydrolysates. The menaquinones detected were MK-9(H₄), MK-9(H₆), MK-9(H₈), and MK-9(H₂). The polar lipid profile was found to contain diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylinositol. The major cellular fatty acids were found to be iso-C_16:0, iso-C_17:0, anteiso-C_15:0, and C_16:1 ω7c. The DNA G+C content of the draft genome sequence, consisting of 7.6 Mbp, was 73.1%. Analysis of the 16S rRNA gene sequence showed that strain LD120^T belongs to the genus Streptomyces, with the highest sequence similarity to Streptomyces azureus NRRL B-2655^T (98.97%), but phylogenetically clustered with Streptomyces anandii NRRL B-3590^T (98.62%). Multilocus sequence analysis based on five other house-keeping genes (atpD, gyrB, rpoB, recA, and trpB) and the low level of DNA–DNA relatedness, as well as phenotypic differences, allowed strain LD120^T to be differentiated from its closely related strains. Therefore, the strain was concluded to represent a novel species of the genus Streptomyces, for which the name Streptomycesphyscomitrii sp. nov. was proposed. The type strain was LD120^T (=CCTCC AA 2018049^T = DSM 110638^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).

Rhodococcus oryzae sp. nov., a novel actinobacterium isolated from rhizosphere soil of rice (Oryza sativa L.)

A Gram-stain-positive, non-motile, creamy-white actinobacterium, which has an elementary branching rod-coccus life cycle was isolated from the rhizosphere soil of rice (Oryza sativa L.) collected from Northeast Agricultural University in Harbin, Heilongjiang province, north-east PR China, and its taxonomic status was examined by using a polyphasic approach. Results from the 16S rRNA gene sequence study showed that the isolate, designated strain NEAU-CX67^T, belonged to the genus Rhodococcus and formed a cluster with Rhodococcus maanshanensis DSM 44675^T, Rhodococcus kronopolitis NEAU-ML12^T and Rhodococcus tukisamuensis JCM 11308^T (98.3, 98.1 and 97.7% gene sequence similarity, respectively). The major fatty acids were C_16 : 0, 10-methyl C_18 : 0, C_18 : 1 ω9c and C_16 : 1 ω7c. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major isoprenoid quinone was MK-8(H₂). Whole-cell hydrolysates contained meso-diaminopimelic acid. Arabinose, galactose and ribose were detected as diagnostic sugars from whole-cell hydrolysates. Mycolic acids were detected. The genomic DNA G+C content of strain NEAU-CX67^T was 64.6 mol%. Strain NEAU-CX67^T exhibited low average nucleotide identity and digital DNA-DNA hybridization values with R. maanshanensis DSM 44675^T (92.1 and 45.4 %) and R. tukisamuensis JCM 11308^T (81.9 and 24.4 %). On the basis of results of phylogenetic, genotypic, physiological and chemotaxonomic analysis, strain NEAU-CX67^T is considered to represent a novel species of the genus Rhodococcus for which the name Rhodococcus oryzae sp. nov. is proposed. The type strain is NEAU-CX67^T (=DSM 107701^T=CCTCC AB 2018233^T).

Streptomyces montanus sp. nov., a novel actinomycete isolated from soil

A novel actinomycete, designated strain NEAU-C151T, was isolated from soil collected from Mount Song and characterized using a polyphasic approach. Analysis of the 16S rRNA gene sequence indicated that strain NEAU-C151T belongs to the genus Streptomyces and exhibited 97.5, 97.4 and 97.4 % similarities to Streptomyces lincolnensis NRRL 2936T, Streptomyces coacervatus AS-0823T, and Streptomyces longisporus ISP 5166T, respectively. The assignment of strain NEAU-C151T to the genus Streptomyces was confirmed by chemotaxonomic data: anteiso-C15 : 0, C16 : 0, iso-C16 : 0, C16 : 1 (ω7c) and anteiso-C17 : 0 as the major cellular fatty acids; whole-cell sugars contained ribose and glucose; phospholipid profile consisted of diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), unidentified phospholipid (PL), unidentified lipids (L) and phosphatidylinositol mannoside (PIM); the menaquinones were MK-9(H4), MK-9(H6), MK-10(H2) and MK-9(H8). However, multilocus sequence analysis based on five other house-keeping genes (atpD, gyrB, recA, rpoB, and trpB), DNA–DNA relatedness and phenotypic data showed that strain NEAU-C151T could be distinguished from its closest relatives. Consequently, strain NEAU-C151T represents a novel species of the genus Streptomyces , for which the name Streptomyces montanus sp. nov. is proposed. The type strain is NEAU-C151T (=CGMCC 4.7498T=DSM 107808T).

Glycomyces albidus sp. nov., a novel actinobacterium isolated from rhizosphere soil of wheat (Triticum aestivum L.)

A novel actinobacterium, designated strain NEAU-7082^T, was isolated from rhizosphere soil of wheat (Triticum aestivum L.) and characterized by using a polyphasic approach. Morphological and chemotaxonomic characteristics confirmed the affiliation of strain NEAU-7082^T to the genus Glycomyces. 16S rRNA gene sequence analysis indicated that strain NEAU-7082^T belonged to the genus Glycomyces and was closely related to Glycomyces mayteni JCM 16217^T (99.0 % 16S rRNA gene sequence similarity), Glycomyces sambucus DSM 45047^T (98.4 %), Glycomyces scopariae DSM 44968^T (98.3 %), Glycomyces paridis DSM 102295^T (98.1 %), Glycomyces artemisiae NBRC 109773^T (98.0 %) and Glycomyces dulcitolivorans DSM 105121T (97.9 %). Phylogenetic analysis using the 16S rRNA gene sequence showed that the strain formed a stable clade with G. mayteni JCM 16217^T and clustered with G. sambucus DSM 45047^T, G. scopariae DSM 44968^T, G. artemisiae NBRC 109773^T and G. dulcitolivorans DSM 105121T in the genus Glycomyces. The cell wall contained meso-diaminopimelic acid and the whole-cell hydrolysates were glucose and xylose. The polar lipid profile consisted of diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), glycolipid (GL), phosphatidylinositol mannoside (PIM) and an unidentified lipid (UL). The menaquinones were MK-11(H₄), MK-11 and MK-10. Major fatty acids were anteiso-C_15 : 0, iso-C_16 : 0 and anteiso-C_17 : 0. These chemotaxonomic data substantiated the affiliation of strain NEAU-7082^T to the genus Glycomyces. The DNA G+C content was 71.3 mol%. A combination of DNA-DNA hybridization results and some phenotypic characteristics demonstrated that strain NEAU-7082^T could be distinguished from its closest relatives. Therefore, strain NEAU-7082^T is considered to represent a novel species of the genus Glycomyces, for which the name Glycomyces albidus sp. nov. is proposed. The type strain is NEAU-7082^T (=CCTCC AA 2019045^T=JCM 33458^T).

Characterization of Streptomyces piniterrae sp. nov. and Identification of the Putative Gene Cluster Encoding the Biosynthesis of Heliquinomycins

A novel actinomycete producing heliquinomycin and 9’-methoxy-heliquinomycin, designated strain jys28^T, was isolated from rhizosphere soil of Pinus yunnanensis and characterized using a polyphasic approach. The strain had morphological characteristics and chemotaxonomic properties identical to those of members of the genus Streptomyces. It formed spiral chains of spores with spiny surfaces. The menaquinones detected were MK-9(H₆), MK-9(H₈) and MK-9(H₄). The major fatty acids were iso-C_16:0, C_15:0, C_16:1ω7с and anteiso-C_15:0. The phospholipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine and phosphatidylinositol mannoside. The DNA G + C content of the draft genome sequence, consisting of 8.5 Mbp, was 70.6%. Analysis of the 16S rRNA gene sequence showed that strain jys28^T belongs to the genus Streptomyces with the highest sequence similarities to Streptomyces chattanoogensis NBRC 13058^T (99.2%) and Streptomyces lydicus DSM 40002^T (99.2%) and phylogenetically clustered with them. Multilocus sequence analysis based on five other house-keeping genes (atpD, gyrB, rpoB, recA and trpB) and the low level of DNA–DNA relatedness and phenotypic differences allowed the novel isolate to be differentiated from its most closely related strains. Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomycespiniterrae sp. nov. is proposed. Furthermore, the putative biosynthetic gene cluster of heliquinomycins was identified and the biosynthetic pathway was discussed. The type strain is jys28^T (=CCTCC AA 2018051^T =DSM 109823^T).

Georgenia wutianyii sp. nov. and Georgenia yuyongxinii sp. nov. isolated from plateau pika (Ochotona curzoniae) on the Qinghai-Tibet plateau of China

Four novel bacterial strains, designated Z294^T, Z311, Z443^T and Z446, were isolated from the intestinal contents of plateau pika (Ochotona curzoniae) on the Qinghai-Tibet Plateau of China. Cells were Gram-stain-positive, catalase-positive, oxidase-negative, aerobic, non-motile and short-rod shaped. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the four isolates belong to the genus Georgenia, but clearly separate from the currently recognized species. Both type strains (Z294^T and Z443^T) shared low 16S rRNA gene sequence similarity, digital DNA-DNA hybridization relatedness and average nucleotide identity values with Georginia satyanarayanai NBRC 107612^T, G. subflava JCM 19765^T, G. ruanii JCM 15130^T and G. thermotolerans DSM 21501^T and against each other. The genomic DNA G+C contents of strains Z294^T and Z443^T were 73.3 and 70 %, respectively. The major cellular fatty acids of strain Z294^T were anteiso-C_15 : 0, anteiso-C_15 : 1 A and C_16 : 0, in contrast to anteiso-C_15 : 0 and anteiso-C_15 : 1 A for strain Z443^T. Both type strains (Z294^T and Z443^T) shared the following common features: glucose, rhamnose and ribose as cell-wall sugars; MK-8(H₄) as major menaquinone; alanine, glutamic acid and lysine as cell-wall amino acids; and diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and one unidentified phosphoglycolipid as polar lipids. Comparing the phenotypic and phylogenetic features among the four strains and their related organisms, strains Z294^T and Z443^T represent two novel species within the genus Georgenia, for which the names Georgenia wutianyii sp. nov. (type strain Z294^T=CGMCC 1.16428^T=DSM 106344^T) and Georgenia yuyongxinii sp. nov. (type strain Z443^T=CGMCC 1.16435^T=DSM 106174^T) are proposed.

Mumia zhuanghuii sp. nov., isolated from the intestinal contents of plateau pika (Ochotona curzoniae) on the Qinghai-Tibet Plateau

Two Gram-staining-positive, catalase-positive, oxidase-negative, aerobic, non-motile, irregular rod-shaped bacterial strains (Z350^T and Z527) were isolated from intestinal contents of plateau pika (Ochotona curzoniae) from the Qinghai-Tibet Plateau, PR China. Results of phylogenetic analyses based on 16S rRNA gene sequences indicated that strain Z350^T belongs to the genus Mumia (family Nocardioidaceae) but clearly differs from the currently recognized species Mumia xiangluensis DSM 101040^T (98.4 % similarity) and Mumia flava DSM 27763^T (97.4 %). Strain Z350^T had a DNA G+C content of 70.7 mol% and shared 80.4 and 76.7 % average nucleotide identity values and 23.4 and 20.6 % in silico DNA-DNA hybridization relatedness with M. xiangluensis DSM 101040^T and M. flava DSM 27763^T, respectively. Further phylogenetic analyses based on 497 core genes indicated that our isolates were members of the genus Mumia but separated from all existing genera within the family Nocardioidaceae. The major cellular fatty acids were C_{18 : 1} ω9c and 10-methyl C_{18 : 0}. The cell wall contained ll-diaminopimelic acid as the diamino acid, and rhamnose, ribose and glucose as whole cell-wall sugars. MK-9(H₄) was detected as the major menaquinone. Polar lipids present were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and one unidentified phospholipid. Based on distinct differences in the genotypic and phenotypic data from the two Mumia species, a novel species, Mumia zhuanghuii sp. nov., is proposed. The type strain is Z350^T (=CGMCC 4.7464^T=DSM 106288^T).

Cellulomonas shaoxiangyii sp. nov., isolated from faeces of Tibetan antelope (Pantholops hodgsonii) on the Qinghai-Tibet Plateau

Two Gram-stain-positive, catalase-positive and oxidase-negative, aerobic, non-motile, cellobiose-utilizing, short-rod-shaped strains (Z28^T and Z29) were isolated from faeces of Tibetan antelope (Pantholops hodgsonii) collected on the Qinghai-Tibet Plateau. Strain Z28^T shared 98.1, 98.0, 97.8 and 97.4 % 16S rRNA gene similarity, 24.1, 22.8, 23.2 and 26.3 % digital DNA-DNA hybridization relatedness and 80.8, 80.0, 80.7 and 80.9 % average nucleotide identity values with Cellulomonas oligotrophica DSM 24482^T, Cellulomonas flavigena DSM 20109^T, Cellulomonas iranensis DSM 14785^T and Cellulomonas terrae JCM 14899^T, respectively. Results from further phylogenetic analyses based on the 16S rRNA gene and 148 core genes indicated that strains Z28^T and Z29 were closest to C. oligotrophica DSM 24482^T and C. flavigena DSM 20109^T, but clearly separated from the currently recognized species of the genus Cellulomonas. The genomic DNA G+C content of strain Z28^T was 75.3 mol%. The major cellular fatty acids were anteiso-C_15 : 0, anteiso-C_15 : 1 A, C_16 : 0 and anteiso-C_17 : 0. Ribose and mannose were detected as the whole-cell sugars. The major respiratory quinone was MK-9(H₄) and ornithine was the diamino acid of the cell wall. The polar lipids present in strain Z28^T were phosphatidylethanolamine, five phospholipids, two aminophospholipids, aminolipid and three unidentified lipids. Comparison of phenotypic and phylogenetic features between the two strains and the related organisms revealed that Z28^T and Z29 represent a novel species of the genus Cellulomonas, for which the name Cellulomonas shaoxiangyii sp. nov. is proposed. The type strain is Z28^T (=CGMCC 1.16477^T=DSM 106200^T).

Streptomyces triticagri sp. nov. and Streptomyces triticirhizae sp. nov., two novel Actinobacteria isolated from the rhizosphere soil of wheat (Triticum aestivum L.)

Two novel Actinobacteria, designated strains NEAU-YY421^T and NEAU-YY642^T, were isolated from the rhizosphere soil of wheat (Triticum aestivum L.) collected from Zhumadian, Henan Province, PR China and characterized using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains NEAU-YY421^T and NEAU-YY642^T belonged to the genus Streptomyces and strain NEAU-YY421^T was most closely related to Streptomyces fumanus CGMCC 4.1732^T (97.9 % sequence similarity) and Streptomyces naganishii DSM 40282^T (97.8 %), and that of strain NEAU-YY642^T to Streptomyces zhaozhouensis LZS-5^T (98.0 %) and Streptomyces sedi YIM 65188^T (97.5 %). The cell walls of the two strains contained ll-diaminopimelic acid as the diagnostic diamino acid and the whole-cell hydrolysates were glucose and ribose. Multilocus sequence analysis using the concatenated sequences of the atp D, gyr B, rec A, rpo B and trp B genes showed that the two strains formed separate branches in the genus Streptomyces. Moreover, a combination of DNA-DNA hybridization results and cultural and physiological properties indicated that the two strains can be distinguished from their closest phylogenetic relatives. Therefore, strains NEAU-YY421^T and NEAU-YY642^T belong to two novel species in the genus Streptomyces, for which the names Streptomyces triticagri sp. nov. (NEAU-YY421^T=CGMCC 4.7476^T=DSM 106775^T) and Streptomyces triticirhizae sp. nov. (NEAU-YY642^T=CCTCC AA 2018092^T=DSM 107172^T) are proposed, respectively.

Taxonomic Characterization, and Secondary Metabolite Analysis of Streptomyces triticiradicis sp. nov.: A Novel Actinomycete with Antifungal Activity

The rhizosphere, an important battleground between beneficial microbes and pathogens, is usually considered to be a good source for isolation of antagonistic microorganisms. In this study, a novel actinobacteria with broad-spectrum antifungal activity, designated strain NEAU-H2^T, was isolated from the rhizosphere soil of wheat (Triticum aestivum L.). 16S rRNA gene sequence similarity studies showed that strain NEAU-H2^T belonged to the genus Streptomyces, with high sequence similarities to Streptomyces rhizosphaerihabitans NBRC 109807^T (98.8%), Streptomyces populi A249^T (98.6%), and Streptomyces siamensis NBRC 108799^T (98.6%). Phylogenetic analysis based on 16S rRNA, atpD, gyrB, recA, rpoB, and trpB gene sequences showed that the strain formed a stable clade with S. populi A249^T. Morphological and chemotaxonomic characteristics of the strain coincided with members of the genus Streptomyces. A combination of DNA-DNA hybridization results and phenotypic properties indicated that the strain could be distinguished from the abovementioned strains. Thus, strain NEAU-H2^T belongs to a novel species in the genus Streptomyces, for which the name Streptomyces triticiradicis sp. nov. is proposed. In addition, the metabolites isolated from cultures of strain NEAU-H2^T were characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS) analyses. One new compound and three known congeners were isolated. Further, genome analysis revealed that the strain harbored diverse biosynthetic potential, and one cluster showing 63% similarity to natamycin biosynthetic gene cluster may contribute to the antifungal activity. The type strain is NEAU-H2^T (= CCTCC AA 2018031^T = DSM 109825^T).

Herbidospora galbida sp. nov., a novel actinobacterium isolated from soil

A novel actinobacterium, designated strain NEAU-GS14^T, was isolated from soil of a flower bed in a residential area in Sanya, Hainan Province, China, and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics of the strain coincided with members of the genus Herbidospora. The 16S rRNA gene sequence analysis showed that strain NEAU-GS14^T belongs to the genus Herbidospora and was most closely related to Herbidospora daliensis JCM 18061^T (98.8 %), other type strains of species of the genus Herbidospora were found to be less than 98.7 %. Phylogenetic analysis using the 16S rRNA gene sequences showed that the strain formed a cluster with Herbidospora daliensis JCM 18061^T. Cell wall contained meso-diaminopimelic acid as the major diamino acid and the whole-cell hydrolysates were glucose, madurose and ribose. The major polar lipids were diphosphatidylglycerol, hydroxyphosphatidylethanolamine, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphoglycolipids and two phosphatidylinositol mannosides. The predominant menaquinone was MK-10(H₄). Major fatty acids were 10-methly C_17 : 0 and C_17 : 0, these chemotaxonomic data supported the affiliation of strain NEAU-GS14^T to the genus Herbidospora. The DNA G+C content was 70.6 mol%. Furthermore, the strain could be clearly distinguished by digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values and some phenotypic characteristics. Therefore, it is proposed that strain NEAU-GS14^T represents a novel species of the genus Herbidospora, for which the name Herbidospora galbida sp. nov. is proposed. The type strain is NEAU-GS14^T (=CCTCC AA 2018040^T=JCM 33459^T).

Actinomadura harenae sp. nov., a novel actinomycete isolated from sea sand in Sanya

A novel actinomycete, designated strain NEAU-Ht49^T, was isolated from sea sand sampled in Sanya and characterized by using a polyphasic approach. The 16S rRNA gene sequence analysis showed that strain NEAU-Ht49^T was most closely related to Actinomadura rhizosphaerae SDA37^T (98.8 %), Actinomadura logoneensis NEAU-G17^T (98.6 %), Actinomadura oligospora ATCC 43269^T (98.6 %) and Actinomadura gamaensis NEAU-Gz5^T (98.6 %). The results of phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain NEAU-Ht49^T formed a cluster with A. rhizosphaerae SDA37^T, A. logoneensis NEAU-G17^T, A. oligospora ATCC 43269^T, A. gamaensis NEAU-Gz5^T and Actinomadura rupiterrae CS5-AC15^T (96.4 %). Meso-diaminopimelic acid was detected in its cell walls and glucose, madurose, mannose and ribose were detected in whole-cell hydrolysate. The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositolmannoside and two unidentified lipids. The majoy menaquinone was MK-10(H₆) and the minor menaquinones were MK-9(H₄) and MK-9(H₈). The major fatty acids were C_16 : 0, C_18 : 1ω9c, 10-methyl C_18 : 0 and iso-C_16 : 0. Moreover, morphological and chemotaxonomic characteristics of properties of strain NEAU-Ht49^T also confirmed the affiliation of the isolate to the genus Actinomadura. However, DNA-DNA relatedness, physiological and biochemical data showed that strain NEAU-Ht49^T could be distinguished from its closest relatives. Therefore, strain NEAU-Ht49^T represents a novel species of the genus Actinomadura, for which the name Actinomadura harenae sp. nov. is proposed, with strain NEAU-Ht49^T (=CGMCC 4.7499^T=JCM 32659^T) as the type strain.

Streptomyces oryziradicis sp. nov., a novel actinomycete isolated from rhizosphere soil of rice (Oryza sativa L.)

A novel actinobacterium, designated strain NEAU-C40^T, was isolated from the rhizosphere soil of rice (Oryza sativa L.) collected from Northeast Agricultural University in Harbin, Heilongjiang province, north-east PR China, and was characterized using a polyphasic approach. On the basis of results of 16S rRNA gene sequence analysis, strain NEAU-C40^T belongs to the genus Streptomyces, and shares highest sequence similarities with Streptomyces polygonati CGMCC 4.7237^T (97.9%) and Streptomyces abietis DSM 42080^T (97.9%). Morphological and chemotaxonomic characteristics of the strain also supported its assignment to the genus Streptomyces. Cell walls contained ll-diaminopimelic acid and the whole-cell hydrolysates were glucose, rhamnose and ribose. The major menaquinones were identified as MK-9(H₈) and MK-9(H₆). The major fatty acids were iso-C_16:0, anteiso-C_15:0, C_16:0 and anteiso-C_17:0. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside and an unidentified lipid. The genomic DNA G+C content of strain NEAU-C40^T was 71.8 mol%. Moreover, multilocus sequence analysis based on five other housekeeping genes (atp D, gyr B, rpo B, rec A and trp B) and the low level of DNA-DNA relatedness allowed the isolate to be differentiated from its most closely related strains. On the basis of phenotypic, genotypic and phylogenetic data, strain NEAU-C40^T can be characterized to represent a novel species of the genus Streptomyces, for which the name Streptomyces oryziradicis sp. nov. is proposed. The type strain is NEAU-C40^T (=DSM 107943^T=CCTCC AA 2018038^T).

Characterization of Streptomyces sporangiiformans sp. nov., a Novel Soil Actinomycete with Antibacterial Activity against Ralstonia solanacearum

Ralstonia solanacearum is a major phytopathogenic bacterium that attacks many crops and other plants around the world. In this study, a novel actinomycete, designated strain NEAU-SSA 1^T, which exhibited antibacterial activity against Ralstonia solanacearum, was isolated from soil collected from Mount Song and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics of the strain coincided with those of the genus Streptomyces. The 16S rRNA gene sequence analysis showed that the isolate was most closely related to Streptomyces aureoverticillatus JCM 4347^T (97.9%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain formed a cluster with Streptomyces vastus JCM4524^T (97.4%), S. cinereus DSM43033^T (97.2%), S. xiangluensis NEAU-LA29^T (97.1%) and S. flaveus JCM3035^T (97.1%). The cell wall contained LL-diaminopimelic acid and the whole-cell hydrolysates were ribose, mannose and galactose. The polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), hydroxy-phosphatidylethanolamine (OH-PE), phosphatidylinositol (PI), two phosphatidylinositol mannosides (PIMs) and an unidentified phospholipid (PL). The menaquinones were MK-9(H₄), MK-9(H₆), and MK-9(H₈). The major fatty acids were iso-C_17:0, C_16:0 and C_17:1 ω9c. The DNA G+C content was 69.9 mol %. However, multilocus sequence analysis (MLSA) based on five other house-keeping genes (atpD, gyrB, recA, rpoB, and trpB), DNA–DNA relatedness, and physiological and biochemical data showed that the strain could be distinguished from its closest relatives. Therefore, it is proposed that strain NEAU-SSA 1^T should be classified as representatives of a novel species of the genus Streptomyces, for which the name Streptomyces sporangiiformans sp. nov. is proposed. The type strain is NEAU-SSA 1^T (=CCTCC AA 2017028^T = DSM 105692^T).

Kribbella jiaozuonensis sp. nov., a novel actinomycete isolated from soil

A novel actinobacterium, designated strain NEAU-THZ27^T, was isolated from soil collected from the Cornel peak in Jiaozuo, Henan Province, PR China and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics of the strain coincided with those of members of the genusKribbella. The results of 16S rRNA gene sequence analysis showed that strain NEAU-THZ27^T belongs to the genus Kribbella and was most closely related to Kribbella podocarpi YPL1^T (98.96 %), Kribbella karoonensis Q41^T (98.89 %), Kribbella aluminosa HKI 0478^T (98.86%) and Kribbella hippodromi S1.4^T (98.85 %), similarities to other type strains of species of the genus Kribbella were found to be less than 98.7 %. Phylogenetic analyses using the 16S rRNA gene sequence and multilocus sequence analysis using the concatenated gene sequences of the gyrB, rpoB, recA, relA and atpD genes all showed that the strain formed a separate branch in the genus Kribbella. The cell wall contained ll-diaminopimelic acid as the major diamino acid and the whole-cell hydrolysates were ribose and glucose. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol and phosphatidylinositol. The predominant menaquinone was MK-9(H₄). Major fatty acids were iso-C_16 : 0, iso-C_14 : 0 and anteiso-C_15 : 0, these chemotaxonomic data supported the affiliation of strain NEAU-THZ27^T to the genus Kribbella. The DNA G+C content was 68.0 mol%. Furthermore, the strain could be clearly distinguished by concatenated gene genetic distances, the combination of DNA-DNA hybridization results and some phenotypic characteristics. Therefore, it is proposed that strain NEAU-THZ27^T represents a novel species of the genus Kribbella, for which the name Kribbella jiaozuonensis sp. nov. is proposed. The type strain is NEAU-THZ27^T (=CGMCC 4.7504^T=DSM 105535^T).

Actinomadura logoneensis sp. nov., a novel actinomycete isolated from the soil

One novel actinobacterial isolate, designated strain NEAU-G17^T, was isolated from muddy soil collected from a riverbank in Chad and characterised using polyphasic approach. Morphological and chemotaxonomic characteristics of this strain coincided with those of the genus Actinomadura. The 16S rRNA gene sequence analysis showed that strain NEAU-G17^T was most closely related to Actinomadura oligospora JCM 10648^T (98.7 %) and Actinomadura gamaensis NEAU-Gz5^T (98.6 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-G17^T formed a cluster with Actinomadura oligospora JCM 10648^T, Actinomadura gamaensis NEAU-Gz5^T and Actinomadura rupiterrae CS5-AC15^T (96.4 %). However, the combination of DNA-DNA hybridisation values and some phenotypic characteristics allowed the isolate to be differentiated from their most closely related species. The major menaquinones were identified as MK-9(H₄), MK-9(H₆) and MK-9(H₈). Their polar lipid profile was found to contain diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, an unidentified phospholipid and an unidentified lipid. The major fatty acids were identified as C_16 : 0, iso-C_16 : 0 and C_18 : 1 ω9c. Therefore, it is proposed that strain NEAU-G17^T should be classified as representative of a novel species of the genus Actinomadura, for which the name Actinomadura logoneensis sp. nov. is proposed. The type strains is NEAU-G17^T (=CGMCC 4.7411^T=DSM 105122^T).

Characterization of Sinomonas gamaensis sp. nov., a Novel Soil Bacterium with Antifungal Activity against Exserohilum turcicum

A novel Gram staining positive, aerobic bacterium NEAU-HV1^T that exhibits antifungal activity against Exserohilum turcicum was isolated from a soil collected from Gama, Hadjer lamis, Chad. It was grown at 10–45 °C (optimum 30 °C), pH 5–10 (optimum pH 8), and 0–4% (w/v) NaCl (optimum 1%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain NEAU-HV1^T was closely related to Sinomonas susongensis A31^T (99.24% sequence similarity), Sinomonas humi MUSC 117^T (98.76%), and Sinomonas albida LC13^T (98.68%). The average nucleotide identity values between NEAU-HV1^T and its most closely related species were 79.34−85.49%. The digital DNA–DNA hybridization values between NEAU-HV1^T and S. susongensis A31^T, S. albida LC13^T, and S. humi MUSC 117^T were 23.20, 23.50, and 22.80%, respectively, again indicating that they belonged to different taxa. The genomic DNA G+C content was 67.64 mol%. The whole cell sugars contained galactose, mannose, and rhamnose. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and four glycolipids. The respiratory quinone system comprised MK-9(H₂), MK-10(H₂), and MK-8(H₂). The major cellular fatty acids (>5%) were anteiso-C_15:0, anteiso-C_17:0, C_16:0, and iso-C_15:0. Based on the polyphasic analysis, it is suggested that the strain NEAU-HV1^T represents a novel species of the genus Sinomonas, for which the name Sinomonas gamaensis sp. nov. is proposed. The type strain is NEAU-HV1^T (= DSM 104514^T = CCTCC M 2017246^T).