A new spectinabilin derivative with cytotoxic activity from ant-derived Streptomyces sp. 1H-GS5.

A new spectinabilin derivative (1) was isolated from the fermentation broth of the ant-derived Streptomyces sp. 1H-GS5, and the structure was elucidated by extensive spectroscopic analysis. Compound 1 showed cytotoxicity against human tumor cell lines A549, HCT-116, and HepG2 with IC50 values of 9.7, 12.8, and 9.1 µg/ml, respectively, which was relative higher than that of spectinabilin.

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).

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

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

Dissolution-precipitation method concatenated sodium alginate/MOF-derived magnetic multistage pore carbon magnetic solid phase extraction for determination of antioxidants and ultraviolet stabilizers in polylactic acid food contact plastics.

Antioxidants and UV stabilizers have some endocrine disrupting effects and liver toxicity. Both types of additives are still widely used in food contact plastics to improve the durability of plastic products. However, efficient and rapid detection of antioxidants and UV stabilizers has been a challenge due to the complexity of the plastic matrix and the low content of antioxidants and UV stabilizers. In this study, a sodium alginate/MOF-derived magnetic multistage pore carbon material (MIL-101(Fe)/SA-CAs) was developed, having the merits of abundant multistage pore structure, large specific surface area, and good magnetic separation properties. Thus, this material was selected as the sorbent for magnetic solid-phase extraction combined with a dissolution-precipitation method for the extraction and purification of antioxidants and UV stabilizers from polylactic acid food contact plastics. The extraction parameters such as sorbent type, sorbent dosage, sample solution pH, ionic strength, sorption time, elution solution type, volume, and time were investigated. Under the optimized conditions, all the analytes determined by UPLC-MS/MS showed good linear range (r > 0.99), detection limit (0.023-3.105 ng g-1), accuracy (70.6-102.3 %), and reproducibility (RSD<9.8 %). Further, the developed method was applied to determine the antioxidants and UV stabilizers in polylactic acid lunch boxes and straws, showing excellent applicability. The results showed that the antioxidants and UV stabilizers were detected in some of the samples, with a maximum detection of antioxidant 1010 at 7297 ng g-1. This study provided a sensitive, efficient, and environmentally friendly method for antioxidants and UV stabilizers in polylactic acid food contact plastics. The ideas for the design of environmentally friendly metal-organic frameworks and biomass composite multifunctional materials would promise in the sample pretreatment field for the emerging contaminants.

Eco-friendly hydrophobic ZIF-8/sodium alginate monolithic adsorbent: An efficient trap for microplastics in the aqueous environment.

Microplastics (MPs), a newly emerging class of environmental contaminants, pose a severe threat to the entire ecosystem. The development of efficient and environmentally responsible adsorbents for removing the MPs is a particularly urgent research. Herein, a kind of monolithic ZIF-8 based adsorbents featuring stable hydrophobicity and micropore-mesopore-macropore hierarchical porous structure were fabricated by in situ growth of ZIF-8 nanoparticles on sodium alginate (SA) framework, and using polydimethylsiloxane (PDMS) as a hydrophobic agent. The monolithic nature of ZIF-8/SA allowed an easy solid-liquid separation process for adsorbents from water environment compared to powdered materials. The hierarchical porous structure ensures a remarkable MPs removal performance. The ZIF-8/SA showed high adsorption capacities of 594, 585, and 282 mg/g for polymethyl methacrylate (PMMA), poly (vinylidene difluoride) (PVDF), and polyvinyl chloride (PVC) respectively, and rapid adsorption kinetic progress within 120 min. The ZIF-8/SA adsorbents also exhibited excellent stability in the presence of interfering ions, acid/alkali, and humic acid, and displayed adsorption performance of > 70 % even in actual aquatic environment such as tap water, river water, and seawater. The results of characterizations showed that the synergistic effect of electrostatic interaction, hydrogen bonding, hydrophobic force, and van der Waals force was the main adsorption mechanism. The well-designed hydrophobic ZIF-8/SA monolithic materials would be promising to rapidly remove the MPs from the water environment.

rGO modified nanoplate-assembled ZnO/CdO junction for detection of NO2.

The triadic composite of ZnO/CdO heterojunction decorated with reduced graphene oxide (rGO) was prepared using a one-step hydrothermal method. The characterizations of morphology, structure and composition to the composite were undertaken by XRD, Raman, SEM, TEM, XPS, UV-vis spectra. The sensing experimental data indicate that the highest response of the ZnO/CdO/rGO (1.0 wt%) composite to ppm-level NO2 is 8 times and 2 times higher than pure ZnO and ZnO/CdO junction, respectively. The composite not only exhibits fast response time and recovery time, high response, but also reveals outstanding stability and repeatability at an operating temperature of 125 °C. The sensing mechanism also has been discussed in detail in the work. The enhancement in gas sensing properties is credited to the development of ZnO/CdO heterojunction and the decoration of rGO with high conductivity. The logarithm of sensitivity in the range of 0.4-2.4 ppm NO2 shows good linear dependence, indicating that the composite based sensor can be used to quantificationally detect low concentration of NO2.

Unique Flexible NiFe2O4@S/rGO-CNT Electrode via the Synergistic Adsorption/Electrocatalysis Effect toward High-Performance Lithium-Sulfur Batteries.

A unique flexible NiFe2O4 hollow sphere@S/rGO-CNT (NiFe2O4@S/C) cathode was rationally designed and synthesized to tackle the issues of lithium-sulfur batteries. In this strategy, the introduced rGO and CNTs offer a flexible and conductive skeleton to facilitate the transport of electrons and/or ions and a physical barrier to confine polysulfides. Furthermore, as an efficient sulfur host, NiFe2O4 hollow spheres can further absorb the soluble polysulfides by strong chemical interaction due to their intrinsic polarity and also serve as a catalyst to promote the redox kinetics of polysulfide conversion. Benefiting from the synergism of the physical confinement, polar chemical adsorption, and catalytic conversion, the as-prepared flexible NiFe2O4@S/C electrode delivers a high initial capacity of 1193 mAh g-1 at 100 mA g-1 and excellent long-term cycling stability up to 500 cycles with a low decay rate of 0.059% per cycle at 500 mA g-1.