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As components of a traditional Chinese herbal medicine with many physiological activities, perilla ketone and isoegomaketone isolated from perilla essential oil are important active components of Perilla frutescens. Recent studies have shown that these two compounds have promising antitumor, antifungal, antirheumatoid arthritis, antiobesity, anti-inflammatory, healing-promoting, and other activities and can be used to combat toxicity from immunotherapy. Therefore, the multitude of pharmacological activities and effects demonstrate the broad research potential of perilla ketone and isoegomaketone. However, no reviews have been published related to the pharmacological activities or effects of perilla ketone and isoegomaketone. The purpose of this review is as follows: (1) outline the recent advances made in understanding the pharmacological activities of perilla ketone and isoegomaketone; (2) summarize their effects; and (3) discuss future research perspectives.

Underground microbial ecosystems have profound impacts on plant health

In this study, we have produced a lightweight foam composite material by a simple freeze-drying method, which is composed of carboxylated multi-walled carbon nanotubes (MWCNTs), mesoporous carbon hollow microspheres (MCHMs), water-based polyurethane (WPU), and polyvinyl alcohol (PVA). MCHMs were prepared by a novel and facile method. We found that the electromagnetic shielding performance of foam composites can be adjusted by adjusting the density of foam composites, and the electromagnetic shielding performance of composites can be enhanced through the synergistic effect of hollow mesoporous carbon and MWCNTs. The composite material with a density of 232.8042 mg·cm−3 and 40 wt% MWCNT has a δ of 30.2 S·m−1 and SE of 23 dB. After adding 10 wt% MCHMs to the composite material, δ reaches 33.2 S·m−1, and SE reaches 28 dB. Both absorption losses accounted for 70%. The increase in the content of MWCNT, the increase in density, and the introduction of MCHMs all have a positive effect on the δ and SE of the composite material.

With the outstanding features of low cost and simple operation, adsorption is an effective strategy to remove organic pollutants that caused irreversible harm to organisms from water. UiO-67, a kind of stable zirconiumbased MOF material, has been considered as a promising adsorbent with appropriate pore size, superior structure and strong affinity with various organic pollutants. Thus, UiO-67 is a great potential material in effectively removing organic pollutants from water. In this review, the research status of UiO-67 and its derivatives in terms of various modification strategies and adsorption property improvements and mechanisms to different organic pollutants are analyzed and compared.

Antibiotics have gradually received extensive attention as a new organic pollutant in the water environment, which is detrimental to aquatic organisms and humans. It was found in groundwater, surface water, especially contaminated water. Hence, it’s imperative to take effective methods to remove residual antibiotics in contaminated water. Zeolitic imidazole frameworks (ZIFs) with adjustable porous structures and large specific surface areas are conducive to adsorbing antibiotic pollutants. This review summarized ZIF-8 and its derivative nanomaterials covering the related researches on adsorbents for antibiotics in contaminated water. Besides, we emphasized how ZIF-8 derivative materials are more convenient for practical application in water treatment. In addition, the adsorption mechanism was further illustrated. This review aims to provide a theoretical foundation basis for the application of ZIF-8 in water treatment.

In this study, we used a novel and facile hard-template etching method to manufacture mesoporous carbon hollow microspheres (MCHMs). We prove that the dielectric ability and microwave absorption of MCHMs can be adjusted by structural characteristics. When the average particle size of MCHMs is 452 nm, the paraffin composite material mixed with 10 wt% MCHMs can achieve a maximum reflection loss value of -51 dB with a thickness of 4.0 mm at 7.59 GHz. When the average particle size of MCHMs is 425 nm, the effective absorption bandwidth of the paraffin composite material mixed with 10 wt% MCHMs can achieve a broad bandwidth of 7.14 GHz with a thickness of 2.5 mm. Compared with other microwave absorbers, MCHMs possess high microwave absorption capacity and broad microwave absorption bandwidth with as low as a 10 wt% filler ratio. This excellent microwave absorption performance is due to the internal cavity and the mesoporous shell of MCHMs. By rationally designing the structure of MCHMs, excellent microwave absorption performance can be acquired. Meanwhile, this design concept based on a rational design of spherical structure can be extended to other spherical absorbers.

Bacillus spp. have been widely reported with the ability to control plant diseases. In this work, we analyzed the whole genome of LJBS06, which was isolated from grapevine rhizosphere soil. In view of physiological and biochemical characteristics, genome data, and phylogenetic analysis of 16S rRNA, LJBS06 was affiliated with Bacillus stercoris. LJBS06 showed antagonistic activities against a variety of plant pathogens. The inhibition rate of Magnaporthe oryzae was up to 75.05% and the inhibition rates of Colletotrichum gloeosporioides, Coniothyrium diplodiella, and Botrytis cinerea were all above 50% in the plate assays. The genome of LJBS06 had a 4,154,362-bp circular chromosome, with an average GC content of 43.96%, containing an 82,935-bp plasmid with a GC content of 35.18%. The circular chromosome of LJBS06 contained 4231 protein-coding genes, 30 rRNA genes, and 87 tRNA genes, including genes related to the synthesis of plant defense-related enzymes and the promotion of plant growth. Meanwhile, 11 gene clusters involved in biosynthesis of secondary metabolites were present in the genome of LJBS06. In conclusion, our findings indicated that LJBS06 strain had the necessary genetic machinery to control plant pathogens and provided insights for future studies of the biocontrol mechanisms of B. stercoris LJBS06.

Bacillus spp. have been widely reported with the ability to control plant diseases. In this work, we analyzed the whole genome of LJBS06, which was isolated from grapevine rhizosphere soil. In view of physiological and biochemical characteristics, genome data, and phylogenetic analysis of 16S rRNA, LJBS06 was affiliated with Bacillus stercoris. LJBS06 showed antagonistic activities against a variety of plant pathogens. The inhibition rate of Magnaporthe oryzae was up to 75.05% and the inhibition rates of Colletotrichum gloeosporioides, Coniothyrium diplodiella, and Botrytis cinerea were all above 50% in the plate assays. The genome of LJBS06 had a 4,154,362-bp circular chromosome, with an average GC content of 43.96%, containing an 82,935-bp plasmid with a GC content of 35.18%. The circular chromosome of LJBS06 contained 4231 protein-coding genes, 30 rRNA genes, and 87 tRNA genes, including genes related to the synthesis of plant defense-related enzymes and the promotion of plant growth. Meanwhile, 11 gene clusters involved in biosynthesis of secondary metabolites were present in the genome of LJBS06. In conclusion, our findings indicated that LJBS06 strain had the necessary genetic machinery to control plant pathogens and provided insights for future studies of the biocontrol mechanisms of B. stercoris LJBS06. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-03000-6.

With the rapid increase of intelligent communication equipment, electromagnetic pollution is becoming more and more serious, and the research and application of high-performance electromagnetic shielding materials have attracted great attention from the academic and engineering circles. Traditional metal-based electromagnetic shielding materials have high reflection loss, high density, and are difficult to process. Polymer-based materials with carbon materials as fillers have the advantages of flexibility, light weight, corrosion resistance and low processing costs. They have become the most important materials in the field of electromagnetic shielding in recent years. However, the conductivity of conductive polymer materials is not high. Therefore, improving the electromagnetic shielding performance and the proportion of absorption loss under low density conditions have become key issues for polymer-based electromagnetic shielding materials. MWCNT/MCHMs/WPU composites were prepared by a solution mixing method, with 20 wt%, 40 wt%, 60 wt% MWCNTs and 40 wt% MWCNT/10 wt% MCHMs as fillers. By comparing the effects of different MWCNT content and MCHMs on the dielectric properties, electromagnetic shielding properties and mechanical properties of the MWCNT/MCHMs/WPU composites, the relationship between the structure and properties of the composites has been explored. The 0.6 mm WPU/60 wt% MWCNT composite has an electrical conductivity of 95.4 S m−1 and an electromagnetic shielding effectiveness of 40 dB in the X band. Adding 10 wt% MCHMs to the WPU/40 wt% MWCNT composite material can significantly improve the composite. The δ of the material increased from 51.2 S m−1 to 55.4 S m−1, and the SE increased from 30 dB to 33 dB. The research results show that the increase in MWCNT content and MCHMs is beneficial to improving the electrical conductivity and electromagnetic shielding performance of the composite materials.

Plantaricin LPL-1, produced by Lactobacillus plantarum LPL-1, is a novel class IIa bacteriocin with bactericidal activity against foodborne bacteria. The aim of this present study was to understand the antibacterial activity and mechanism of plantaricin LPL-1 against Listeria monocytogenes 54002, one of the Gram-positive bacteria sensitive to this bacteriocin and typical foodborne pathogenic bacteria in the food industry. The minimal inhibitory concentration (MIC) was confirmed as 16 μg/mL, and the time-kill kinetics showed that plantaricin LPL-1 significantly decrease the viable cell numbers of L. monocytogenes 54002 in a time-dependent and dose-dependent manner. The antibacterial mechanism was investigated using confocal laser-scanning microscopy, scanning and transmission electron microscopy, spectrofluorimeter, spectrophotometer and Real-Time PCR system, which demonstrated that plantaricin LPL-1 facilitated pores formation, damaged cell membrane integrity, increased membrane permeability, triggered intracellular material leakage, induced collapse of proton motive force, and inhibited expression levels of genes related to virulence factors, biofilm formation factors, and RNA polymerase sigma factor. Hence, the bactericidal mechanism of plantaricin LPL-1 against L. monocytogenes was clarified at cellular and molecular levels.

International cyber mediation is currently the most demanded service in the legal services market. The growth of cyber-attacks on the Internet, a large number of scams with cryptocurrency, falsification of products, goods and services sold on the Internet, as well as theft of money from credit cards and from online accounts of Internet users - all this requires the help of cyber lawyers. Since the Asia-Pacific region is the most developed and most populous Internet space in the world, the market for Internet mediator services should be the most profitable.

The soil bacterium Bacillus subtilis can form robust biofilms, which are important for its survival in the environment. B. subtilis also exhibits natural competence. By investigating competence development in B. subtilis in situ during biofilm formation, we reveal that robust biofilm formation often greatly reduces the frequency of competent cells within the biofilm. We then characterize a cross-pathway regulation that allows cells in these two developmental events to undergo mutually exclusive cell differentiation during biofilm formation. Finally, we discuss potential biological implications of limiting competence in a bacterial biofilm., Environmental strains of the soil bacterium Bacillus subtilis have valuable applications in agriculture, industry, and biotechnology; however, environmental strains are genetically less accessible. This reduced accessibility is in sharp contrast to laboratory strains, which are well known for their natural competence, and a limitation in their applications. In this study, we observed that robust biofilm formation by environmental strains of B. subtilis greatly reduced the frequency of competent cells in the biofilm. By using model strain 3610, we revealed a cross-pathway regulation that allows biofilm matrix producers and competence-developing cells to undergo mutually exclusive cell differentiation. We further demonstrated that the competence activator ComK represses the key biofilm regulatory gene sinI by directly binding to the sinI promoter, thus blocking competent cells from simultaneously becoming matrix producers. In parallel, the biofilm activator SlrR represses competence through three distinct mechanisms involving both genetic regulation and cell morphological changes. Finally, we discuss the potential implications of limiting competence in a bacterial biofilm. IMPORTANCE The soil bacterium Bacillus subtilis can form robust biofilms, which are important for its survival in the environment. B. subtilis also exhibits natural competence. By investigating competence development in B. subtilis in situ during biofilm formation, we reveal that robust biofilm formation often greatly reduces the frequency of competent cells within the biofilm. We then characterize a cross-pathway regulation that allows cells in these two developmental events to undergo mutually exclusive cell differentiation during biofilm formation. Finally, we discuss potential biological implications of limiting competence in a bacterial biofilm.

Bacillus velezensis LPL061, which shows strong exopolysaccharide (EPS) producing capacity, was isolated from carnations in Beijing, China. The complete genome of LPL061 comprised a single circular chromosome (3,907,268 bp; G+C content of 46.7%) with 3,737 coding DNA sequences, 26 rRNA, and 89 tRNA. According to genome analysis, 12 protein-coding genes which related to polysaccharide biosynthesis in LPL061 were identified. Comparative genome analysis revealed that the EPS biosynthetic gene cluster was relatively conserved among Bacillus species. EPS showed approximately 60% inhibitory activity on the α-glucosidase at 100 μg/mL. The results of quantitative reverse transcription PCR further demonstrated that compared to insulin-resistant model with insulin (500 μg/mL) (without EPS treatment), the insulin-resistant HepG2 cells treated with EPS decreased the expression of phosphoenolpyruvate carboxykinase (PEPCK) from 4.425 to 0.1587, glucose-6-phosphatase (G6Pase) decreased from 4.272 to 0.1929, and glycogen synthase kinase3β (GSK(3)β) decreased from 2.451 to 0.993, respectively. Meanwhile, EPS treatment increased GS expression and resulted in intracellular glycogen concentration increased from 28.30% to 86.48%, which further supported that EPS form LPL061 could reduce the concentration of blood glucose effectively. These results could be beneficial for better understanding of the hypoglycemic mechanism of B. velezensis LPL061 EPS and developing an EPS-based anti-diabetic agent in the future. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13205-020-02228-y) contains supplementary material, which is available to authorized users.

The anti-diabetic effects of Bifidobacterium animalis 01 and its potential mechanisms were investigated. Male SD rats were given a high-fat chow diet with low-dose streptozotocin (30 mg/kg BW) to induce T2DM. The supplements with B. animalis 01 were given in a pre- and post-treatment method. Oral administration of B. animalis 01 decreased food and water intake, blood glucose concentration, and glycosylated hemoglobin level. Treatment with B. animalis 01 improved OGTT, HOMA-IR, lipid profiles, representative cytokines, and liver injury markers in the serum. B. animalis 01 also exhibited hepatoprotective effects by reducing hepatic tissues injuries, increasing the glycogen levels, and improving the antioxidant indexes. Furthermore, B. animalis 01 treatment showed beneficial influence on the gene expressions of hepatic glucose metabolism and IRS/PI3K/AKT pathway. Moreover, B. animalis 01 administration positively regulated hepatic Keap1/Nrf2 pathway. The results suggested that the hepatic protective effect of B. animalis 01 against diabetes attributed to IRS/PI3K/AKT and Keap1/Nrf2 signaling activation.

Bacillus velezensis LPL-K103, which shows strong antifungal function, was isolated from the surface of lemon in Beijing, China. The complete genome of B. velezensis LPL-K103 contains a circular chromosome of 3,933,292 bp (46.61% G+C content). According to genomic analysis, 4080 protein-coding genes, 113 RNAs (27 rRNAs + 86 tRNAs), and a non-ribosomal peptide synthase gene cluster involved in antifungal cyclic lipopeptide bacillomycin L biosynthesis were identified. Here, we propose that the biosynthesis pathway of bacillomycin L in LPL-K103 depends on its genome information. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13205-019-1995-y) contains supplementary material, which is available to authorized users.

ATP-dependent proteases play essential roles in both protein quality control and the regulation of protein activities in bacteria. ClpYQ (also known as HslVU) is one of several highly conserved ATP-dependent proteases in bacteria. The regulation and biological function of ClpYQ have been well studied in Gram-negative bacteria, but are poorly understood in Gram-positive species. In this study, we showed that in the Gram-positive bacterium Bacillus subtilis, the ΔclpYQ deletion mutant formed early and robust biofilms, while swarming motility was severely impaired. Colonies of the ΔclpYQ mutant were also much less mucoid on agar plates, indicating the loss of the production of secreted γ-poly-dl-glutamic acid (γ-PGA). Global proteomic analysis using isobaric tags for relative and absolute quantification (iTRAQ) confirmed that a number of proteins involved in motility, chemotaxis and the production of γ-PGA were less abundant in the ΔclpYQ mutant. The results from both iTRAQ and Western immunoblotting showed that levels of the biofilm master repressor SinR were modestly reduced in the ΔclpYQ mutant, but probably significantly enough to alter biofilm regulation due to the ultrasensitivity of the expression of biofilm genes to SinR protein levels. Western immunoblotting also showed that the abundance of CodY, whose gene is clustered with clpYQ in the same operon, was not impacted on by ΔclpYQ. Lastly, our results suggested that, unlike in Escherichia coli, ClpYQ does not play an essential role in heat-shock response in both B. subtilis and Bacillus cereus. In conclusion, we propose that the ClpYQ protease is primarily involved in multicellular development in B. subtilis.

Bacteriocins are antibacterial proteins or peptides synthesized by ribosomes to inhibit or kill both closely related and non-related bacterium. Class IIa bacteriocins possess high activity against foodborne pathogen Listeria monocytogenes. A novel strain Lactobacillus plantarum LPL-1 was isolated from fermented fish and considered as a bacteriocin producing probiotic with great antibacterial activity against Listeria monocytogenes 54002. The complete genome of L. plantarum LPL-1 contains one circular chromosome and plasmid. According to the genome, biosynthetic genes of bacteriocin including precursor, immunity protein,accessory protein and transporter protein were identified; and biosynthetic mechanism of class IIa bacteriocin was also further analyzed. The antibacterial activity of purified bacteriocin against L.monocytogenes54002 was determined and the diameter of inhibition zone was about 16.6 mm by vernier caliper. This work provided the complete genome information of L. plantarum LPL-1 that could benefit for understanding the biosynthetic mechanism of class IIa bacteriocin as well as the potential application of L. plantarum LPL-1 in nutraceutical and pharmaceutical.

As a nano-fertilizer, carbon dots have good application prospects in crop planting. And its unique fluorescent properties and low toxicity make it become a good biomarker material. In this paper, CDs is prepared by a facile synthesis method. Mung bean as a model plant, and gradient concentration of N-CDs solution for breeding bean sprouts. The results show that 0.15 mg⋅L−1 carbon point solution can promote plant growth. At the same time, we also reveal that carbon dots segmented migration in bean sprouts, discuss the transfer path of carbon dots in bean sprouts, and find that the absorption of carbon dots solution by bean sprouts is linear, and its R2=0.98. We find that carbon dots can maintain good fluorescence properties in bean sprouts. A metabolic residue experiment is carried out and it is found that the carbon dots still exist in the bean sprouts after 24 h.

As the important delivery power equipment, condition assessment of XLPE cable has been always the focus of attention. This paper proposes a new method to realize the condition assessment by utilizing the signal propagation characteristics. In this method, the complex permittivity is solved by the attenuation coefficient and the shifting constant of phase angle. Then the dielectric loss factor (tan δ) is obtained with only the voltage signal. To verify the proposed method, the XLPE cable is modeled and the simulation experiments are conducted. First, the vector fitting is applied to achieve the rational approximation of series impedance and shunt admittance. Meanwhile, the cable is modeled by the Г-type circuits cascading considering the distributed parameter effect. Then, simulation experiments of 100 m and 3000 m cables in different insulation conditions are carried out based on the cable model. Finally, the effect of random error and synchronization error on the proposed method is also discussed. The simulation results demonstrate the feasibility and effectiveness of the proposed method.

The strain Bifidobacterium animalis 01, isolated from centenarians, showed promising antioxidant potential in our previous studies. In this study, the genome information on strain 01 and the important antioxidant components are presented. The complete genome comprises a single circular chromosome (1,931,632 bp; 60.49% G + C content) with 1569 coding DNA sequences, 52 tRNA, and 9 rRNA operons. Based on phylogenomic analyses, strain 01 was designated as B. animalis subsp. lactis 01. The genomic analysis reveals that at least eight protein-coding genes are antioxidant-related genes. The conditions for simulating the oxidative stress have been determined. The results of quantitative reverse transcription PCR further demonstrated that the genes encoding the thioredoxin system (ahpC, ahpF, bcp, trxB, trxA, nrdH, and msrAB) and non-enzyme factors of the divalent cation transporter gene (mntH) were upregulated under the H(2)O(2) challenge, indicating that the eight genes were effective components of the antioxidant system. The results of this study could benefit for understanding the antioxidant mechanism of B. animalis 01 and future utilization of it as a potential antioxidant agent. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13205-019-1890-6) contains supplementary material, which is available to authorized users.

In Bacillus subtilis, robust biofilm formation requires large quantities of ferric iron. Here we show that this process requires preferential production of a siderophore precursor, 2,3-dihydroxybenzoate, instead of the siderophore bacillibactin. A large proportion of iron is associated extracellularly with the biofilm matrix. The biofilms are conductive, with extracellular iron potentially acting as electron acceptor. A relatively small proportion of ferric iron is internalized and boosts production of iron-containing enzymes involved in respiratory electron transfer and establishing strong membrane potential, which is key to biofilm matrix production. Our study highlights metabolic diversity and versatile energy generation strategies within B. subtilis biofilms., Biofilm formation in Bacillus subtilis requires high levels of ferric iron. Here, Qin et al. show that iron accumulation requires production of dihydroxybenzoate (a precursor in siderophore biosynthesis), and matrix-associated iron may be acting as extracellular electron acceptor during respiratory electron transfer.

Bacteriocins are peptides or proteins synthesized by bacterial ribosomes that show killing or inhibitory activities against different groups of bacteria. Bacteriocins are considered potential alternatives to traditional antibiotics, preservatives in pharmaceutical and food industries. A strain L-Q11 isolated from orchard soil was phylogenetically characterized as Bacillus subtilis based on 16S rRNA gene sequencing analysis. A novel class I bacteriocin (Subtilin L-Q11), was identified and purified from L-Q11 cell-free supernatant in a four-step procedure, including salt precipitation, cation exchange, gel filtration, and reverse-phase high-performance liquid chromatography (RP-HPLC). The molecular mass (3,552.9 Da) of this novel bacteriocin was determined by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The purified Subtilin L-Q11 exhibited optimal features in pH tolerance, thermostability, and sensitivity to proteases. Further, Subtilin L-Q11 showed inhibitory activities against a number of bacteria including some human pathogens and food spoilage bacteria, in particular Staphylococcus aureus. All these important features make this novel bacteriocin a potential candidate for the development of a new antibacterial drug or food preservative in the future.

The reduction of salt (sodium chloride) in fermented sausages is motivated by the positive association between excessive intake of sodium and some diseases. However, pathogens control and shelf life of fermented sausages is of vital importance when salt is reduced. In this study, we investigated the impacts of an IIa bacteriocin-producing strain, Lactobacillus plantarum LPL-1, on the composition of bacterial community in low-salt fermented sausages by using a culture-independent high-throughput sequencing approach. Meanwhile, impacts of LPL-1 on physicochemical characteristics of low-salt fermented sausages were investigated. Our results showed that LPL-1 changed the bacterial community composition, reduced community diversity and inhibited the growth of spoilage bacteria during fermentation and ripening of low-salt fermented sausages. After fermentation, Lactobacillus was the most abundant genus with the proportion over 90% in sausages which inoculated with LPL-1. We predicted microbial metabolism related to nutrients transport and metabolism enhanced in sausages by inoculating with LPL-1. We also found that the decrease of pH and tyramine, putrescine and cadaverine and total biogenic amines content in sausages inoculated with LPL-1. These findings indicated that L. plantarum LPL-1 can be applied as starter culture to improve the safety of low-salt fermented sausages.

Bacteriocins are ribosomally synthesized peptides or proteins possessing antibacterial activity against foodborne pathogens and spoilage bacteria. A novel bacteriocin, plantaricin LPL-1 was determined as a class IIa bacteriocin according to the YGNGV motif, and producer strain Lactobacillus plantarum LPL-1 was identified based on physio-biochemical characteristics and 16S rDNA sequence. The novel bacteriocin, plantaricin LPL-1 was purified by salt precipitation, cation exchange, gel filtration, and reverse phase high-performance liquid chromatography (RP-HPLC). The molecular mass of plantaricin LPL-1 was 4347.8467 Da by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis and entire amino acid sequence of plantaricin LPL-1 was VIADKYYGNGVSCGKHTCTVDWGEAFSCSVSHLANFGHGKC. Plantaricin LPL-1 possessed the merits of easy degradation by proteases, wide pH stability (2–10), high thermal stability (121°C, 20 min), surfactants stability and bactericidal activity against foodborne spoilage and pathogens bacteria. The mode action and membrane permeabilization of plantaricin was identified. The information of plantaricin LPL-1 indicated that it is not only a novel class IIa bacteriocin, but also a promising natural and safe biologic preservative for the food preservation industry.