Interlayer Polymerization to Construct a Fully Conjugated Covalent Organic Framework as a Metal-Free Oxygen Reduction Reaction Catalyst for Anion Exchange Membrane Fuel Cells.

Two-dimensional (2D) covalent organic frameworks (COFs) have a multilayer skeleton with a periodic π-conjugated molecular array, which can facilitate charge carrier transport within a COF layer. However, the lack of an effective charge carrier transmission pathway between 2D COF layers greatly limits their applications in electrocatalysis. Herein, by employing a side-chain polymerization strategy to form polythiophene along the nanochannels, a conjugated bridge is constructed between the COF layers. The as-synthesized fully conjugated COF (PTh-COF) exhibits high oxygen reduction reaction (ORR) activity with narrowed energy band gaps. Correspondingly, PTh-COF is tested as a metal-free cathode catalyst for anion exchange membrane fuel cells (AEMFCs) which showed a maximum power density of 176 mW cm-2 under a current density of 533 mA cm-2. The density functional theory (DFT) calculation reveals that interlayer conjugated polythiophene optimizes the electron cloud distribution, which therefore enhances the ORR performance. This work not only provides new insight into the construction of a fully conjugated covalent organic framework but also promotes the development of new metal-free ORR catalysts.

Enhanced In Vitro Anti-Photoaging Effect of Degraded Seaweed Polysaccharides by UV/H2O2 Treatment.

The high molecular weight and poor solubility of seaweed polysaccharides have limited their function and application. In this study, ultraviolet/hydrogen peroxide (UV/H2O2) treatment was used to prepare low-molecular-weight seaweed polysaccharides from Sargassum fusiforme. The effects of UV/H2O2 treatment on the physicochemical properties and anti-photoaging activity of S. fusiforme polysaccharides were studied. UV/H2O2 treatment effectively degraded polysaccharides from S. fusiforme (DSFPs), reducing their molecular weight from 271 kDa to 26 kDa after 2 h treatment. The treatment did not affect the functional groups in DSFPs but changed their molar percentage of monosaccharide composition and morphology. The effects of the treatment on the anti-photoaging function of S. fusiforme polysaccharides were investigated using human epidermal HaCaT cells in vitro. DFSPs significantly improved the cell viability and hydroxyproline secretion of UVB-irradiated HaCaT cells. In particular, DSFP-45 obtained from UV/H2O2 treatment for 45 min showed the best anti-photoaging effect. Moreover, DSFP-45 significantly increased the content and expression of collagen I and decreased those of pro-inflammatory cytokines, including interleukin-1ß, interleukin-6, and tumor necrosis factor-α. Thus, UV/H2O2 treatment could effectively improve the anti-photoaging activity of S. fusiforme polysaccharides. These results provide some insights for developing novel and efficient anti-photoaging drugs or functional foods from seaweed polysaccharides.

Unsupervised Learning-Guided Accelerated Discovery of Alkaline Anion Exchange Membranes for Fuel Cells.

Without insight into the correlation between the structure and properties, anion exchange membranes (AEMs) for fuel cells are developed usually using the empirical trial and error method or simulation methods. Here, a virtual module compound enumeration screening (V-MCES) approach, which does not require the establishment of expensive training databases and can search the chemical space containing more than 4.2×105 candidates was proposed. The accuracy of the V-MCES model was considerably improved when the model was combined with supervised learning for the feature selection of molecular descriptors. Techniques from V-MCES, correlating the molecular structures of the AEMs with the predicted chemical stability, generated a ranking list of potential high stability AEMs. Under the guidance of V-MCES, highly stable AEMs were synthesized. With understanding of AEM structure and performance by machine learning, AEM science may enter a new era of unprecedented levels of architectural design.

POMCPs with Novel Two Water-Assisted Proton Channels Accommodated by MXenes for Asymmetric Supercapacitors.

To develop high-performance supercapacitors, the negative electrode is at present viewed as one of the most challenging tasks for obtaining the next-generation of energy storage devices. Therefore, in this study, a polyoxometalate-based coordination polymer [Zn(itmb)3 H2 O][H2 SiW12 O40 ]·5H2 O (1) is designed and prepared by a simple hydrothermal method for constructing a high-capacity negative electrode. Polymer 1 has two water-assisted proton channels, which are conducive to enhancing the electrical conductivity and storage capacity. Then, MXene Ti3 C2 Tx is chosen to accommodate coordination polymer 1 as the interlayer spacers to improve the conductivity and cycling stability of 1, while preventing the restacking of MXene. Expectedly, the produced composite electrode 1@Ti3 C2 Tx shows an excellent specific capacitance (1480.1 F g-1 at 5 A g-1 ) and high rate performance (a capacity retention of 71.5% from 5 to 20 A g-1 ). Consequently, an asymmetric supercapacitor device is fabricated using 1@Ti3 C2 Tx as the negative electrode and celtuce leaves-derived carbon paper as the positive electrode, which demonstrates ultrahigh energy density of 32.2 Wh kg-1 , and power density 2397.5 W kg-1 , respectively. In addition, the ability to illuminate a red light-emitting diode for several minutes validates its feasibility for practical application.

Changes in circulating TCF1- and GARP-associated regulatory T cell subsets reflect the clinical status of patients with chronic HBV infection.

This study aimed to clarify the expression changes and clinical significance of regulatory T (Treg) cells and follicular regulatory T (TFR) cell subsets divided by glycoprotein A repetitions predominant protein (GARP) and T cell factor 1(TCF1) in peripheral blood of patients with chronic HBV infection. The peripheral blood of 26 chronic hepatitis B (CHB) patients, 27 inactive HBsAg carriers and 32 healthy controls were collected and GARP + percentages in Treg and TFR cells were analyzed by flow cytometry. In addition, Treg and TFR cell subsets sorted by CD62L and TCF1 were analyzed and compared. Correlation analyses were performed between Treg and TFR cell subpopulations and clinical parameters as well as cytokine concentrations, including IL-21, IL-10 and TGF-ß1 in plasma. Circulating Treg and TFR levels were elevated in CHB patients. Moreover, GARP and TCF1 were up-regulated in circulating Treg and TFR cells of CHB patients. TCF1 + CD62L- Treg cells were increased while TCF1-CD62L + Treg cells were decreased in CHB patients. TCF1 + CD62L- and TCF1-CD62L- TFR cells were increased while TCF1 + CD62L + TFR cells were decreased in CHB patients. TCF1 + CD62L- Treg cells were positively correlated with HBV DNA, ALT and plasma IL-10, while TCF1 + CD62L + TFR cells were negatively correlated with HBV DNA, HBeAg, HBsAg, ALT, AST, T-BIL and positively correlated with plasma IL-21. Treg and TFR subsets sorted by TCF1, CD62L and GARP were changed in CHB patients. Changes in Treg and TFR functional subsets are associated with antiviral immunity in CHB patients.

Periodic motions and homoclinic orbits in a discontinuous dynamical system on a single domain with multiple vector fields.

In this paper, periodic motions and homoclinic orbits in a discontinuous dynamical system on a single domain with two vector fields are discussed. Constructing periodic motions and homoclinic orbits in discontinuous dynamical systems is very significant in mathematics and engineering applications, and how to construct periodic motions and homoclinic orbits is a central issue in discontinuous dynamical systems. Herein, how to construct periodic motions and homoclinic orbits is presented through studying a simple discontinuous dynamical system on a domain confined by two prescribed energies. The simple discontinuous dynamical system has energy-increasing and energy-decreasing vector fields. Based on the two vector fields and the corresponding switching rules, periodic motions and homoclinic orbits in such a simple discontinuous dynamical system are studied. The analytical conditions of bouncing, grazing, and sliding motions at the two energy boundaries are presented first. Periodic motions and homoclinic orbits in such a discontinuous dynamical system are determined through the specific mapping structures, and the corresponding stability is also presented. Numerical illustrations of periodic motions and homoclinic orbits are given for constructed complex motions. Through this study, using discontinuous dynamical systems, one can construct specific complex motions for engineering applications, and the corresponding mathematical methods and computational strategies can be developed.

Sargassum fusiforme Polysaccharide-Based Hydrogel Microspheres Enhance Crystal Violet Dye Adsorption Properties.

In this study, a polysaccharide-based hydrogel microsphere (SFP/SA) was prepared using S. fusiforme polysaccharide (SFP) and sodium alginate (SA). Fourier transform infrared spectroscopy (FT-IR) demonstrated that SFP was effectively loaded onto the hydrogel microsphere. Texture profile analysis (TPA) and differential scanning calorimetry (DSC) showed that, with the increase of SFP concentration, the hardness of SFP/SA decreased, while the springiness and cohesiveness of SFP/SA increased, and the thermal stability of SFP/SA improved. The equilibrium adsorption capacity of SFP/SA increased from 8.20 mg/g (without SFP) to 67.95 mg/g (SFP accounted 80%) without swelling, and from 35.05 mg/g (without SFP) to 81.98 mg/g (SFP accounted 80%) after 24 h swelling. The adsorption of crystal violet (CV) dye by SFP/SA followed pseudo-first order and pseudo-second order kinetics (both with R2 > 0.99). The diffusion of intraparticle in CV dye was not the only influencing factor. Moreover, the adsorption of CV dye for SFP/SA (SFP accounted 60%) fit the Langmuir and Temkin isotherm models. SFP/SA exhibited good regenerative adsorption capacity. Its adsorption rate remained at > 97% at the 10th consecutive cycle while SFP accounted for 80%. The results showed that the addition of Sargassum fusiforme polysaccharide could increase the springiness, cohesiveness and thermal stability of the hydrogel microsphere, as well as improve the adsorption capacity of crystal violet dye.

Surface Plasmon Resonance Boost Electrocatalytic Alcohol Oxidation over Three-Dimensional PdM (M = Au, Ag, Cu) Nanosheet Assemblies.

Photoelectrocatalytic nanomaterials are promising for direct alcohol fuel cells, but the construction of high-efficiency catalysts remains difficult. We herein successfully synthesized three-dimensional (3D) PdM nanosheet assemblies (PdM NSAs, M = Au, Ag, and Cu) through a seed-mediated growth method, which displayed a typical 3D nanoflower morphology assembled from many two-dimensional ultrathin nanosheets. Due to the open 3D structure and the synergistic and electronic effects between Pd and Ag, the optimized PdAg NSAs showed the highest mass activity (9378 mA mg-1) for the ethylene glycol oxidation reaction. More interestingly, when irradiated with visible light, the mass activity increased to 14 590 mA mg-1, 12.1 times higher than that of the commercial Pd/C (1205 mA mg-1). In addition, the as-obtained catalysts also showed better long-term durability than that of the commercial Pd/C under the condition of with or without visible-light illumination. This work highlights the utilization of light energy in designing excellent photoelectrocatalysts to promote the photoelectrocatalytic performance of anode catalysts for fuel cells.

Improved AP-3 production through combined ARTP mutagenesis, fermentation optimization, and subsequent genome shuffling.

Ansamitocin (AP-3) is an ansamycins antibiotic isolated from Actinosynnema pretiosum and demonstrating high anti-tumor activity. To improve AP-3 production, the A. pretiosum ATCC 31565 strain was treated with atmospheric and room temperature plasma (ARTP). Four stable mutants were obtained by ARTP, of which the A. pretiosum L-40 mutant produced 242.9 mg/L AP-3, representing a 22.5% increase compared to the original wild type strain. With seed medium optimization, AP-3 production of mutant L-40 reached 307.8 mg/L; qRT-PCR analysis revealed that AP-3 biosynthesis-related gene expression was significantly up-regulated under optimized conditions. To further improve the AP-3 production, genome shuffling (GS) technology was used on the four A. pretiosum mutants by ARTP. After three rounds of GS combined with high-throughput screening, the genetically stable recombinant strain G3-96 was obtained. The production of AP-3 in the G3-96 strain was 410.1 mg/L in shake flask cultures, which was 44.5% higher than the L-40 production from the parental strain, and AP-3 was increased by 93.8% compared to the wild-type A. pretiosum. These results suggest that the combination of mutagenesis, seed medium optimization, and GS technology can effectively improve the AP-3 production capacity of A. pretiosum and provide an enabling methodology for AP-3 industrial production.

On infinite homoclinic orbits induced by unstable periodic orbits in the Lorenz system.

In this paper, infinite homoclinic orbits existing in the Lorenz system are analytically presented. Such homoclinic orbits are induced by unstable periodic orbits on bifurcation trees through period-doubling cascades. Each unstable periodic orbit ends at its corresponding homoclinic orbit. Traditional computational methods cannot obtain homoclinic orbits from the corresponding unstable periodic orbits. This is because unstable periodic orbits in the Lorenz system cannot be achieved in numerical simulations. Herein, the stable and unstable periodic motions to chaos on the period-doubling cascaded bifurcation trees are determined through a discrete mapping method. The corresponding homoclinic orbits induced by the unstable periodic orbits are predicted analytically. A period-doubling bifurcation tree of period-1, period-2, and period-4 motions are generated as an example. The homoclinic orbits relative to unstable period-1, period-2, and period-4 motions are determined. Illustrations of homoclinic orbits and periodic orbits are given. This study presents how to determine infinite homoclinic orbits through unstable periodic orbits in three-dimensional or higher-dimensional nonlinear systems.

Single Fault Diagnosis Method of Sensors in Cascade System Based on Data-Driven.

The reliability and safety of the cascade system, which is widely applied, have attached attention increasingly. Fault detection and diagnosis can play a significant role in enhancing its reliability and safety. On account of the complexity of the double closed-loop system in operation, the problem of fault diagnosis is relatively complex. For the single fault of the second-order valued system sensors, a real-time fault diagnosis method based on data-driven is proposed in this study. Off-line data is employed to establish static fault detection, location, estimation, and separation models. The static models are calibrated with on-line data to obtain the real-time fault diagnosis models. The real-time calibration, working flow and anti-interference measures of the real-time diagnosis system are given. Experiments results demonstrate the validity and accuracy of the fault diagnosis method, which is suitable for the general cascade system.

Eco-Friendly Strategy To Improve Durability and Stability of Zwitterionic Capping Ligand Colloidal CsPbBr3 Nanocrystals.

Long-chain zwitterionic ligands have been demonstrated to greatly improve the chemical durability of colloidal CsPbBr3 nanocrystals (NCs) by the chelate effect. However, Br sources are toxic, and the reaction is so dynamic that it is hard to control the size of the crystal. We propose an eco-friendly strategy to improve the chemical durability of colloidal CsPbBr3 NCs. Nontoxic, inexpensive, and directly available benzoyl bromine was used as the Br source, and tri-n-octylphosphine oxide was used as the adjuvant to control the reaction kinetics. Uniform, monodispersed NCs with a size of ∼11 nm were obtained. They had high photoluminescence quantum yields (PLQYs) of above 95% and, especially, showed strong stability against attack by polar solvents. The PLQY remained 80% even after 12 cycles of purification. Furthermore, after 24 h of continuous radiation by 405 nm laser, the photoluminescence (PL) intensity showed negligible decrease, and the wavelength and full width at half-maximum of PL had no significant change.

Antioxidant activity and inhibition of ultraviolet radiation-induced skin damage of Selenium-rich peptide fraction from selenium-rich yeast protein hydrolysate.

The bioactive peptides and trace element selenium (Se) both have good antioxidant activity. However, whether combined Se and bioactive peptides have more excellent antioxidant activity remain unknown. The aim of this study is to prepare a Se-rich peptide fraction containing both Se and peptides from Se-rich yeast protein hydrolysate and investigated its antioxidant activity and effect on ultraviolet B (UVB) radiation-induced skin oxidative damage. The peptide fractions with different molecular weight (MW) and Se content were obtained by enzymatically hydrolyzing normal or Se-rich yeast proteins followed by a filtration process. In vitro free radical scavenging and lipid peroxidation inhibition assays showed that Se-rich peptides fraction with lower MW of <1 kDa (sSeP) had the highest antioxidant activity compared with Se-rich peptide fractions with higher MW of <3 kDa or normal peptide fractions. Oral administration of sSeP significantly decreased the level of malonaldehyde (MDA) in liver and serum, and increased the activity of glutathione peroxidase (GPx) in liver and serum in normal mice. When topically applied on the dorsal skin of mice, sSeP effectively alleviate UVB radiation-induced skin damage and oxidative stress by increasing GPx and catalase activities and glutathione content in skin or serum. Furthermore, sSeP showed a protective effect against H2O2-induced cytotoxicity in cultured human epidermal keratinocytes (HaCaT) cells probably by increasing aquaporin-3 expression and attenuating the phosphorylation of p38 MAPK. Overall, the results showed that Se-rich yeast peptide fraction containing Se and bioactive peptides could be a promising antioxidant nutrient used as food additive to enhance the body's antioxidant ability or as cosmeceutical product to minimize the skin oxidative damage.

Integrative Gene Expression Profiling Analysis to Investigate Potential Prognostic Biomarkers for Colorectal Cancer.

BACKGROUND Despite noteworthy advancements in the multidisciplinary treatment of colorectal cancer (CRC) and deeper understanding in the molecular mechanisms of CRC, many of CRC patients with histologically identical tumors present different treatment response and prognosis. Thus, more evidence on novel predictive and prognostic biomarkers for CRC remains urgently needed. This study aims to identify potential prognostic biomarkers for CRC with integrative gene expression profiling analysis. MATERIAL AND METHODS Differential expression analysis of paired CRC and adjacent normal tissue samples in 6 microarray datasets was independently performed, and the 6 datasets were integrated by the robust rank aggregation method to detect consistent differentially expressed genes (DEGs). Aberrant expression patterns of these genes were further validated in RNA sequencing data. Then, gene set enrichment analysis (GSEA) was performed to investigate significantly dysregulated biological functions in CRC. Finally, univariate, LASSO and multivariate Cox regression models were built to identify key prognostic genes in CRC patients. RESULTS A total of 990 DEGs (495 downregulated and 495 upregulated genes) were acquired after integratedly analyzing the 6 microarray datasets, and 4131 DEGs (2050 downregulated and 2081 upregulated genes) were obtained from the RNA sequencing dataset. Subsequently, these DEGs were intersected and 885 consistent DEGs were finally identified, including 458 downregulated and 427 upregulated genes. Two risky prognostic genes (TIMP1 and LZTS3) and 5 protective prognostic genes (AXIN2, CXCL1, ITLN1, CPT2 and CLDN23) were identified, which were significantly associated with the prognosis of CRC. CONCLUSIONS The 7 genes that we identified would provide more evidence for further applying novel diagnostic and prognostic biomarkers in clinical practice to facilitate personalized treatment of CRC.

An Autonomous Path Planning Model for Unmanned Ships Based on Deep Reinforcement Learning.

Deep reinforcement learning (DRL) has excellent performance in continuous control problems and it is widely used in path planning and other fields. An autonomous path planning model based on DRL is proposed to realize the intelligent path planning of unmanned ships in the unknown environment. The model utilizes the deep deterministic policy gradient (DDPG) algorithm, through the continuous interaction with the environment and the use of historical experience data; the agent learns the optimal action strategy in a simulation environment. The navigation rules and the ship's encounter situation are transformed into a navigation restricted area, so as to achieve the purpose of planned path safety in order to ensure the validity and accuracy of the model. Ship data provided by ship automatic identification system (AIS) are used to train this path planning model. Subsequently, the improved DRL is obtained by combining DDPG with the artificial potential field. Finally, the path planning model is integrated into the electronic chart platform for experiments. Through the establishment of comparative experiments, the results show that the improved model can achieve autonomous path planning, and it has good convergence speed and stability.

2D Molecular Crystal Bilayer p-n Junctions: A General Route toward High-Performance and Well-Balanced Ambipolar Organic Field-Effect Transistors.

Ambipolar organic field-effect transistors (OFETs) are vital for the construction of high-performance all-organic digital circuits. The bilayer p-n junction structure, which is composed of separate layers of p- and n-type organic semiconductors, is considered a promising way to realize well-balanced ambipolar charge transport. However, this approach suffers from severely reduced mobility due to the rough interface between the polycrystalline thin films of p- and n-type organic semiconductors. Herein, 2D molecular crystal (2DMC) bilayer p-n junctions are proposed to construct high-performance and well-balanced ambipolar OFETs. The molecular-scale thickness of the 2DMC ensures high injection efficiency and the atomically flat surface of the 2DMC leads to high-quality p- and n-layer interfaces. Moreover, by controlling the layer numbers of the p- and n-type 2DMCs, the electron and hole mobilities are tuned and well-balanced ambipolar transport is accomplished. The hole and electron mobilities reach up to 0.87 and 0.82 cm2 V-1 s-1 , respectively, which are the highest values among organic single-crystalline double-channel OFETs measured in ambient air. This work provides a general route to construct high-performance and well-balanced ambipolar OFETs based on available unipolar materials.

Fluorescent Imidazolium-Type Poly(ionic liquid)s for Bacterial Imaging and Biofilm Inhibition.

Fluorescent imidazolium-type poly(ionic liquid)s (PIL)s were synthesized by anion exchange of bromide (Br-) in poly(3-butyl-1-vinylimidazolium bromide) (PIL-Br) with a fluorescent anion, namely, 3-(4-(1,2,2-triphenylvinyl)phenoxy)propane-1-sulfonate (TPESO3-). Such an anion exchange provided antibacterial PILs with aggregation-induced emission (AIE) properties that simultaneously kill and image bacteria. These fluorescence and antibacterial properties could be regulated by controlling the Br-/TPESO3- ratio. The fluorescence intensity increases as this ratio increases, while the antibacterial property exhibits an opposite trend. Moreover, the AIE-type PILs are useful for fluorescently imaging dead bacteria (macroscopically and microscopically) and could effectively inhibit biofilm growth. This study provided a convenient method to obtain fluorescent PILs with adjustable antibacterial and imaging properties.

Nonomuraea zeae sp. nov., isolated from the rhizosphere of corn (Zea mays L.).

A novel actinobacterium, designated strain NEAU-ND5T, was isolated from the rhizosphere of corn (Zea mays L.) collected in Heilongjiang Province, north-east China, and characterized using a polyphasic approach. 16S rRNA gene sequence analysis showed that strain NEAU-ND5T was a member of the genus Nonomuraea, with highest sequence similarities to Nonomuraea jabiensis A4036T (98.29 %), Nonomuraea rosea GW12687T (98.25 %), Nonomuraea candida HMC10T (98.22 %), Nonomuraea rhizophila YIM 67092T (98.04 %) and Nonomuraea kuesteri NRRL B-24325T (98.04 %). Similarities to other type strains of the genus Nonomuraea were lower than 98 %. Morphological and chemotaxonomic properties of strain NEAU-ND5T were also consistent with the description of the genus Nonomuraea. The cell wall contained meso-diaminopimelic acid and the whole-cell sugars were glucose, ribose and madurose. The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylmonomethylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major menaquinones were MK-9(H4), MK-9(H2) and MK-9(H0). The predominant cellular fatty acids were iso-C16:0 and 10-methyl C17:0. A combination of DNA-DNA hybridization results and some phenotypic characteristics demonstrated that strain NEAU-ND5T was clearly distinguished from its closely related Nonomuraea species. Consequently, it is concluded that strain NEAU-ND5T represents a novel species of the genus Nonomuraea, for which the name Nonomuraea zeae sp. nov. is proposed. The type strain is NEAU-ND5T (=CGMCC 4.7280T=DSM 100528T).

Promicromonospora alba sp. nov., an actinomycete isolated from the cuticle of Camponotus japonicas Mayr.

A novel actinomycete, designated strain 1C-HV12T, was isolated from the cuticle of Camponotus japonicas Mayr and characterized using a polyphasic approach. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the organism should be assigned to the genus Promicromonospora and that it forms a monophyletic clade with the closest relatives Promicromonospora umidemergens JCM 17975T(99.17 % 16S rRNA gene sequence similarity), Promicromonospora vindobonensis V45T (98.88 %) and Promicromonospora iranensis HM 792T (98.85 %). Moreover, morphological and chemotaxonomic properties of strain 1C-HV12T also confirmed the affiliation of the isolate to the genus Promicromonospora. The peptidoglycan hydrolysates contained alanine, glutamic acid and lysine, and whole-cell sugars were galactose, glucose, rhamnose and ribose. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, an unidentified phosphoglycolipid, an unidentified phospholipid and an unidentified glycolipid. The major menaquinones were MK-9(H4) and MK-9(H2). The predominant cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0. The DNA G+C content was 71.6 mol%. However, the low level of DNA-DNA relatedness and some phenotypic characteristics allowed the isolate to be differentiated from closely related species. Therefore, it is concluded that strain 1C-HV12T represents a novel species of the genus Promicromonospora, for which the name Promicromonospora alba sp. nov. is proposed. The type strain is 1C-HV12T ( = CGMCC 4.7283T = DSM 100490T).

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

A novel actinomycete, designated strain NEAU-G9T, 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-G9T to the genus Streptomyces. Strain NEAU-G9T 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-C16 : 0, anteiso-C15 : 0 and C16 : 0.16S rRNA gene sequence similarity studies showed that strain NEAU-G9T belongs to the genus Streptomyces and exhibits the highest sequence similarity to Streptomyces yanglinensis JCM 13275T (97.75 %). However, phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-G9T is most closely related to Streptomyces misakiensis JCM 4062T (97.12 % sequence similarity). A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-G9T can be clearly distinguished from S. yanglinensis JCM 13275T and S. misakiensis JCM 4062T. Consequently, strain NEAU-G9T represents a novel species of the genus Streptomyces, for which the name Streptomyces polygonati sp. nov. is proposed. The type strain is NEAU-G9T ( = CGMCC 4.7237T = DSM 100521T).