The effects of different fertilization on microbial communities and resistome in agricultural soils with a history of fresh manure application remains largely unclear. Here, soil antibiotic ...resistance genes (ARGs), mobile genetic elements (MGEs) and microbial communities were deciphered using metagenomics approach from a long-term field experiment with different fertilizer inputs. A total of 541 ARG subtypes were identified, with Multidrug, Macrolides-Lincosamides-Streptogramins (MLS), and Bacitracin resistance genes as the most universal ARG types. The abundance of ARGs detected in manure (2.52 ARGs/16 S rRNA) treated soils was higher than chemical fertilizer (2.42 ARGs/16 S rRNA) or compost (2.37 ARGs/16 S rRNA) amended soils. The higher abundance of MGEs and the enrichment of Proteobacteria were observed in manure treated soils than in chemical fertilizer or compost amended soils. Proteobacter and Actinobacter were recognized as the main potential hosts of ARGs revealed by network analysis. Further soil pH was identified as the key driver in determining the composition of both microbial community and resistome. The present study investigated the mechanisms driving the microbial community, MGEs and ARG profiles of long-term fertilized soils with ARGs contamination, and our findings could support strategies to manage the dissemination of soil ARGs.
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•Fertilization altered the composition of both soil microbiome and resistome.•Multidrug, MLS and Bacitracin resistance genes are the most universal ARG types.•Proteobacter and Actinobacter were identified as the main hosts of ARGs.•Manure treated soils stimulates the propagation of ARGs in soil.•Both the profiles of microbial community and resistome are determined by soil pH.
Stroke is a prominent contributor to global mortality and morbidity, thus necessitating the establishment of dependable diagnostic indicators. The objective of this study was to ascertain metabolites ...linked to sphingolipid metabolism and assess their viability as diagnostic markers for stroke.
Two cohorts, consisting of 56 S patients and 56 healthy volunteers, were incorporated into this investigation. Metabolite data was obtained through the utilization of Ultra Performance Liquid Chromatography and Tandem Mass Spectrometry (UPLC-MS/MS). The mass spectrometry data underwent targeted analysis and quantitative evaluation utilizing the multiple reaction monitoring mode of triple quadrupole mass spectrometry. Various data analysis techniques, including Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA), least absolute shrinkage and selection operator (LASSO) regression, Support Vector Machine (SVM), logistic regression, and Receiver Operating Characteristic (ROC) curves were employed.
A comprehensive analysis detected a total of 129 metabolites related to sphingolipid metabolism, encompassing ceramides, 1-phosphoceramides, phytoceramides, glycosphingolipids, sphingomyelins, and sphingomyelins. The implementation of OPLS-DA analysis revealed significant disparities between individuals with stroke and controls, as it successfully identified 31 metabolites that exhibited significant differential expression between the two groups. Furthermore, functional enrichment analysis indicated the participation of these metabolites in diverse biological processes. Six metabolic markers, namely CerP(d18:1/20:3), CerP(d18:1/18:1), CerP(d18:1/18:0), CerP(d18:1/16:0), SM(d18:1/26:1), and Cer(d18:0/20:0), were successfully validated as potential diagnostic markers for stroke. The utilization of ROC analysis further confirmed their diagnostic potential, while a logistic regression model incorporating these markers demonstrated robust efficacy in distinguishing stroke patients from healthy controls.
these identified metabolic markers exhibit clinical significance and hold promise as valuable tools for the diagnosis of stroke.
Intensive management has greatly altered natural forests, especially forests around the world are increasingly being converted into economic plantations. Soil microbiota are critical for community ...functions in all ecosystems, but the effects of microbial disturbance during economic plantation remain unclear. Here, we used Escherichia coli O157:H7, a model pathogenic species for bacterial invasion, to assess the invasion impacts on the soil microbial community under intensive management. The E. coli invasion was tracked for 135 days to explore the instant and legacy impacts on the resident community. Our results showed that bamboo economic plantations altered soil abiotic and biotic properties, especially increasing pH and community diversity. Higher pH in bamboo soils resulted in longer pathogen survivals than in natural hardwood soils, indicating that pathogen suppression during intensive management should arouse our attention. A longer invasion legacy effect on the resident community (P < 0.05) were found in bamboo soils underlines the need to quantify the soil resilience even when the invasion was unsuccessful. Deterministic processes drove community assembly in bamboo plantations, and this selection acted more strongly during by E. coli invasion than in hardwood soils. We also showed more associated co-occurrence patterns in bamboo plantations, suggesting more complex potential interactions within the microbial community. Apart from community structure, community functions are also strongly related to the resident species associated with invaders. These findings provide new perspectives to understand intensive management facilitates the bacterial invasion, and the impacts would leave potential risks on environmental and human health.
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•Intensive management induced higher pH, facilitating the bacterial invasion.•Intensive management enhanced links in bacterial co-occurrence networks.•Intensive management dominated more deterministic processes following bacterial invasion.•Bacterial invasion altered resident species which strongly related to community functions.
Sodium-ion batteries have received widespread attention for the large-scale energy storage systems due to the abundant sodium source. The P2-Na0.67Fe0.5Mn0.5O2 cathode material is a promising energy ...storage candidate because of its high theoretical capacity and low cost. In this work, the relationship of morphology and electrochemical performances of P2-Na0.67Fe0.5Mn0.5O2 cathode materials were investigated by controlling solid-state synthesis method and using scanning electron microscope and multiple electrochemical tests. The impacts for the morphology and structure of the cathode are investigated by controlling high-temperature calcination process to illustrate the heterogeneous phase mechanism and the electrochemical performances improvement. The results show that the morphology and structure are more uniform and integrated at the calcination temperature of 900 °C after pre-calcination, with moderate and uniform particle size, and the increase of temperature promotes the atomic rearrangement in the solid-phase reaction. It was also observed that the material in the compacted state showed smooth particles with uniform particle size and a more complete crystal structure, as well as improved specific capacity. It is exhibited an initial discharge specific capacity of 161.35 mAh/g, while the cycling performance was slightly inferior to than that of the uncompacted sample.
•P2-type Na0.66Fe0.5Mn0.5O2 was synthesized by solid-state method.•The relationship between the sintering process and the crystal structure as well as the microscopic morphology of the material was investigated.•The electrochemical properties of the materials were modulated.
Soil nutrient supply and resistance to pathogen invasion are critical to crop yield during agricultural production. Crop production is often hampered by co-occurring nutrient and pathogen stresses, ...but the relationship between soil nutrient status and disease suppression remains unclear. Here, we conducted a meta-analysis based on 406 observations from 55 studies to decipher the relationships between soil nutrient supply and disease suppression against bacterial wilt disease caused by R. solanacearum. We found that the contents of soil organic carbon (SOC), total nitrogen (TN), available potassium (AK) and available phosphorus (AP) were significantly higher in relatively disease suppressive soils than in conducive soils. Soil AP showed a significantly negative correlation with both crop disease incidence (DI) and disease severity (DSI). SOC was significantly and negatively correlated with DI and DSI in general, but a positive correlation with DI was found when SOC content was higher than 1.3%. Then for nutrient stoichiometry in soil, we found that the ratio of carbon to nitrogen (C/N), maximum to 22, was significantly and negatively correlated to the DI, but was positively correlated to DSI when C/N was higher than about 30. And the ratio of TN to AP (TN/AP) showed significantly positive correlations with both DI and DSI in soil. Further in applied organic fertilizer, the ratio of nitrogen to phosphorus (N/P) was significantly and negatively correlated with DI when N/P was lower than about 5, but was positively correlated with DI when higher than that. Our results demonstrated that the quantity and stoichiometry of phosphorus, organic carbon and nitrogen in soil and applied fertilizer, notably the prevention of nutrient deficiency and the balance of different nutrients, play an important role in supporting soil suppressiveness to R. solanacearum wilt disease, and this implied a possible trade-off between nutrient acquisition and pathogen defense in soil ecosystems.
•Disease-suppressive soils accompanied with better soil nutrient status.•Increase of SOC and AP contents reduced disease incidence and severity.•Balance between C and N, N and P could promote soil disease suppression.
Understanding how distinct processes operate in mediating community assembly is a long-standing theme in (microbial) ecology. Particularly in soil microbial communities, we still lack a fundamental ...appreciation of how assembly processes structure communities at the fine-scale level of soil aggregates. In this study, samples from a long-term agricultural field subjected to different fertilization regimes were used to quantify the relative influences of stochastic and deterministic processes on soil bacterial community assembly. First, we found bacterial communities to be more phylogenetically clustered in larger soil aggregates comparatively to small aggregates (Spearman's r = −0.366, P < 0.05). Second, we found the overall relative influence of selection to gradually decrease with an increase of aggregate size (Mantel r = 0.161, P < 0.01). By partitioning aggregate sizes and fertilization regimes, we found that sites subjected to fertilization (including chemical, organic, and bio-organic fertilizers) displayed a stronger relaxation of selection and an increased influence of stochasticity with an increase in aggregate size; a pattern not significantly observed at the control (unfertilized) treatment. Collectively, our results highlight the importance of evaluating community assembly at the fine-scale levels of soil aggregates and illustrate how regional level disturbances (i.e., agricultural management) exert an influence on the dynamic interplay of stochastic and deterministic processes.
•Bacterial communities are more phylogenetically clustered in larger soil aggregates.•Soil aggregates mediate the balance between stochastic and deterministic processes.•Deterministic process of homogeneous selection is dominated in all soil aggregates.
•An indirect method of measuring the extinction angle is proposed.•TPMM has the same accuracy as the measured extinction angle method in judging CFs.•TPMM reduces the dependence on the high accuracy ...of the external hardware measurement device.•EDCIR can effectively reduce the number of CFs comparing with VDCOL and CFPREV.
Accurate, simple identification and suppression of repetitive commutation failures are of great significance to the safe and stable operation of the line-commutated converter-based high-voltage direct current (LCC-HVDC). Through the analysis of mathematical models of inverter side converter and DC transmission system. This paper proposes a variable that has an important influence on commutation failure: equivalent DC input resistance. Therefore, a measurement method is proposed, which takes into account the phase deviation of the fundamental commutation line voltage and uses equivalent DC input resistance as the input of the established mathematical model to measure the extinction angle. Meanwhile, according to the characteristics of equivalent DC input resistance, a method based on constant equivalent DC input resistance (EDCIR) to suppress repetitive commutation failures is proposed. Finally, several simulations are conducted on the CIGRE HVDC benchmark and GuiguangII model to validate the effectiveness of the proposed measurement method(TPMM) in the accuracy and suppression of commutation failure. The simulation results show that the proposed measurement method has the same accuracy as the measured extinction angle method and is higher than that of the minimum voltage drop method commonly used in practical engineering in judging commutation failure. At the same time, the proposed method to suppress can effectively reduce the number of commutation failures under single-phase and three-phase ground faults comparing with voltage-dependent current order limiter (VDCOL) and commutation failure prevention and control (CFPREV).
Summary
Host‐associated fungi can help protect plants from pathogens, and empirical evidence suggests that such microorganisms can be manipulated by introducing probiotic to increase disease ...suppression. However, we still generally lack the mechanistic knowledge of what determines the success of probiotic application, hampering the development of reliable disease suppression strategies.
We conducted a three‐season consecutive microcosm experiment in which we amended banana Fusarium wilt disease‐conducive soil with Trichoderma‐amended biofertilizer or lacking this inoculum. High‐throughput sequencing was complemented with cultivation‐based methods to follow changes in fungal microbiome and explore potential links with plant health.
Trichoderma application increased banana biomass by decreasing disease incidence by up to 72%, and this effect was attributed to changes in fungal microbiome, including the reduction in Fusarium oxysporum density and enrichment of pathogen‐suppressing fungi (Humicola). These changes were accompanied by an expansion in microbial carbon resource utilization potential, features that contribute to disease suppression. We further demonstrated the disease suppression actions of Trichoderma‐Humicola consortia, and results suggest niche overlap with pathogen and induction of plant systemic resistance may be mechanisms driving the observed biocontrol effects.
Together, we demonstrate that fungal inoculants can modify the composition and functioning of the resident soil fungal microbiome to suppress soilborne disease.
Non-ribosomal peptides (NRPs) are one of the largest groups of natural microbial secondary metabolites, which include peptides such as the antibiotics vancomycin and gramicidin, as well as ...lipopeptides (surfactin, iturin A and bacillomycin). In this study, banana Fusarium wilt disease suppressive and conducive soils were chosen to investigate the role of microbes that harbor the NRPS gene in disease suppression based on the 454-pyrosequencing platform and real-time PCR technique. The results showed that higher abundances and diversity of microbes that harbor the NRPS gene were observed in the suppressive soil samples than in the conducive soil. According to the results of the DNA sequences blastx of NRPS, the main microbial taxa harboring the NRPS gene were identified, and Pseudomonas in Proteobacteria and Streptomyces in Actinobacteria might be remarkably related to Fusarium wilt disease suppression. Furthermore, the Mantel test showed that compared with bacteria community and chemical properties, the microbial community harboring the NRPS gene had a more significant impact on the disease incidences of Fusarium wilt. This study provided non-specific relationships between groups of microbes harboring NRPS genes and Fusarium wilt disease suppression suggesting potential interaction based on correlation evidence, and pointed out a potential mechanism of suppressive soil.
