Identification of a New B-Cell Epitope on the Capsid Protein of Avian Leukosis Virus and Its Application.

Avian leukosis virus (ALV) is an avian oncogenic retrovirus that can impair immunological function, stunt growth and decrease egg production in avian flocks. The capsid protein (P27) is an attractive candidate for ALV diagnostics. In the present study, a new hybridoma cell (1F8) stably secreting an anti-P27 monoclonal antibody (mAb) was developed. The mAb exhibited a high affinity constant (Ka) of 8.65 × 106.0 L/mol, and it could be used for the detection of ALV-A/B/J/K strains. Moreover, a total of eight truncated recombinant proteins and five synthetic polypeptides were utilized for the identification of the B-cell epitopes present on P27. The results revealed that 218IIKYVLDRQK227 was the minimal epitope recognized by 1F8, which had never been reported before. Additionally, the epitopes could strongly react with different ALV subgroup's specific positive serum and had a complete homology among all the ALV subgroups strains. Finally, a new sandwich ELISA method was created for the detection of ALV antigens, demonstrating increased sensitivity compared to a commercially available ELISA kit. These results offer essential knowledge for further characterizing the antigenic composition of ALV P27 and will facilitate the development of diagnostic reagents for ALV.

A Prussian blue analog-based copper-aluminum layered double hydroxide for cesium removal from water: fabrication, density functional theory-based molecular modeling, and the adsorption mechanism.

A new type of adsorbent, a Prussian blue analog-based copper-aluminum layered double hydroxide (PBA@CuAl-LDH), was successfully synthesized using a one-step method for the removal of radioactive Cs+ from wastewater. The adsorption performance, characteristics and the underlying adsorption mechanism of PBA@CuAl-LDH were systematically examined. The results showed that PBA@CuAl-LDH exhibited excellent adsorption performance, with a maximum adsorption capacity of 109.2 mg g-1. Over 85% of PBA@CuAl-LDH can be recycled, and the material exhibited only a 6.6% loss in adsorption performance. The adsorption process was well-fitted using the pseudo-second-order kinetic model and the Freundlich isotherm model, revealing the surface heterogeneity of the composite adsorbent. A molecular model of PBA@CuAl-LDH was constructed by combining density functional theory and multiple instrumental characterization techniques. Our results indicate that PBA crystals can be generated between layers and on the surface. Ion exchange was revealed as the main adsorption mechanism of Cs+ by PBA@CuAl-LDH. Specifically, the interstitial spaces of the PBA crystals generated between the layers and on the surface played an important role in ion exchange. These findings provide concrete theoretical support for radioactive pollution control and have significant value in directing the fabrication of cesium removal materials and their future engineering application.

Regulatory roles of extracellular polymeric substances in uranium reduction via extracellular electron transfer by Desulfovibrio vulgaris UR1.

The pathway of reducing U(VI) to insoluble U(IV) using electroactive bacteria has become an effective and promising approach to address uranium-contaminated water caused by human activities. However, knowledge regarding the roles of extracellular polymeric substances (EPS) in the uranium reduction process involving in extracellular electron transfer (EET) mechanisms is limited. Here, this study isolated a novel U(VI)-reducing strain, Desulfovibrio vulgaris UR1, with a high uranium removal capacity of 2.75 mM/(g dry cell). Based on a reliable EPS extraction method (45 °C heating), manipulation of EPS in D. vulgaris UR1 suspensions (removal or addition of EPS) highlighted its critical role in facilitating uranium reduction efficiency. On the second day, U(VI) removal rates varied significantly across systems with different EPS contents: 60.8% in the EPS-added system, 48.5% in the pristine system, and 22.2% in the EPS-removed system. Characterization of biogenic solids confirmed the reduction of U(VI) by D. vulgaris UR1, and the main products were uraninite and UO2 (2.88-4.32 nm in diameter). As EPS formed a permeable barrier, these nanoparticles were primarily immobilized within the EPS in EPS-retained/EPS-added cells, and within the periplasm in EPS-removed cells. Multiple electroactive substances, such as tyrosine/tryptophan aromatic compounds, flavins, and quinone-like substances, were identified in EPS, which might be the reason for enhancement of uranium reduction via providing more electron shuttles. Furthermore, proteomics revealed that a large number of proteins in EPS were enriched in the subcategories of catalytic activity and electron transfer activity. Among these, iron-sulfur proteins, such as hydroxylamine reductase (P31101), pyruvate: ferredoxin oxidoreductase (A0A0H3A501), and sulfite reductase (P45574), played the most critical role in regulating EET in D. vulgaris UR1. This work highlighted the importance of EPS in the uranium reduction by D. vulgaris UR1, indicating that EPS functioned as both a reducing agent and a permeation barrier for access to heavy metal uranium.

Theoretical and experimental investigations of enhanced uranium(VI) adsorption using a nitrogen doping strategy.

With the ongoing development and utilization of nuclear energy, uranium pollution has become an increasingly serious issue. Although many adsorbents are able to remove hexavalent uranium (U(VI)) from aqueous solution, the development of a high capacity adsorbent exhibiting superior stability would be beneficial. Grafting poly(amidoxime) (PAO) onto reduced graphene oxide (rGO) provides suitable U(VI) adsorption performance but the PAO is prone to agglomeration. The present work used density functional theory calculations to predict that PAO would bond with pyrrolic N atoms in nitrogen-doped rGO (N-rGO). To confirm this, PAO-grafted rGO (PAO-rGO) and PAO-grafted N-rGO (PAO-N-rGO) were prepared and characterized and the successful grafting of PAO on N-rGO was demonstrated. Adsorption experiments demonstrated that PAO-N-rGO exhibit superb U(VI) adsorption performance compared with the original PAO-rGO under acidic conditions. As for competing metal ions, Cu2+, Al3+, and Ca2+ have a greater impact on U(VI) adsorption than Na+, Mg2+, and K+ both for PAO-rGO and PAO-N-rGO. The maximum adsorption capacities of PAO-rGO and PAO-N-rGO for U(VI) were calculated to be 1500.26 and 1545.95 mg g-1, respectively. The mechanism of nitrogen doping promoting uranium(VI) adsorption can be attributed to enhanced PAO grafting and improvement of adsorption performance of the rGO. This work demonstrates that nitrogen doping is a viable strategy for enhancing the U(VI) adsorption performance of PAO-rGO.

Occurrence of polycyclic aromatic compounds and potentially toxic elements contamination and corresponding interdomain microbial community assembly in soil of an abandoned gas station.

Bacteria, archaea and fungi usually coexist in various soil habitats and play important roles in biogeochemical cycle and remediation of contamination. Despite their significance, their combined bioassembly pattern, ecological interactions and driving factors in contaminated soils still remain obscure. To fill the gap, a systemic investigation on the characteristics of microbial community including bacteria, archaea and fungi, assembly patterns and environmental driving factors was conducted in an abandoned gas station soils which were contaminated by polycyclic aromatic compounds and potentially toxic elements for decades. The results showed that the soils were contaminated excessively by benzo[a]pyrene (0.46-2.00 mg/kg) and Dibenz[a,h]anthracene (0.37-1.30 mg/kg). Multitudinous contaminant-degrading/resistant microorganisms and unigenes were detected, indicating potential of the soils to mitigate the pollution. Compared with fungi and archaea, the bacteria had higher community diversity and were more responsive to seasonal shifts. Functional genes (nidB, nahAb, nahAa, adhP, adh, adhC, etc.) involved in biodegradation were highly enriched in summer (1.96% vs 1.80%). The co-occurrence network analysis showed summer communities exhibit a more robust network structure and positive interactions than winter communities. The fungi Neocucurbitaria, Penicillium, Fusarium, Chrysosporium, Knufia, Filobasidium, Wallemia and Rhodotorula were identified as the keystone taxa, indicating that fungi also had important positions in the interdomain molecular ecological networks of both seasons. The network topological properties and |ßNTI| (66.7%-93.3% greater than 2) results indicated the deterministic assembly processes of the microbial communities in the contaminated soil. Acenaphthylene, benzo[b]fluoranthene, indeno[1,2,3-cd]perylene, benzo[g,h,i]pyrene and 9-fluorenone were the key environmental factors driving the deterministic assembly processes of the interdomain microbial community in the contaminated soil. These findings extended our knowledge of interdomain microbial community assembly mechanisms and ecological patterns in natural attenuation and provide valuable guidance in associated bioremediation strategies.

Occurrence of polycyclic aromatic compounds and interdomain microbial communities in oilfield soils.

Soil polycyclic aromatic compound (PAC) pollution as a result of petroleum exploitation has caused serious environmental problems. The unclear assembly and functional patterns of microorganisms in oilfield soils limits the understanding of microbial mechanisms for PAC elimination and health risk reduction. This study investigated the polycyclic aromatic hydrocarbons (PAHs) and substituted PAHs (SPAHs) occurrence, and their impact on the bacteria-archaea-fungi community diversity, co-occurrence network and functionality in the soil of an abandoned oilfield. The results showed that the PAC content in the oilfield ranged from 3429.03 µg kg-1 to 6070.89 µg kg-1, and risk assessment results suggested a potential cancer risk to children and adults. High molecular weight PAHs (98.9%) and SPAHs (1.0%) contributed to 99.9% of the toxic equivalent concentration. For microbial analysis, the abundantly detected degraders and unigenes indicated the microbial potential to mitigate pollutants and reduce health risks. Microbial abundance and diversity were found to be negatively correlated with health risk. The co-occurrence network analysis revealed nonrandom assembly patterns of the interdomain microbial communities, and species in the network exhibited strong positive connections (59%). The network demonstrated strong ecological linkages and was divided into five smaller coherent modules, in which the functional microbes were mainly involved in organic substance and mineral component degradation, biological electron transfer and nutrient cycle processes. The keystone species for maintaining microbial ecological functions included Marinobacter of bacteria and Neocosmospora of fungi. Additionally, benzo [g,h,i]pyrene, dibenz [a,h]anthracene, indeno [1,2,3-cd]perylene and total phosphorus were the key environmental factors driving the assembly and functional patterns of microbial communities under pollution stress. This work improves the knowledge of the functional pattern and environmental adaptation mechanisms of interdomain microbes, and provides valuable guidance for the further bioremediation of PAC-contaminated soils in oilfields.

A strategy for enhancing the photoactivity of g-C3N4-based single-atom catalysts via sulphur doping: a theoretical study.

Single-atom catalysts (SACs) have received intense attention owing to their maximum utilization efficiency of metal atoms and high catalytic activity. Although SACs possess many merits, such as high activity, selectivity and stability in photocatalysis, the difficulty of fabricating atomically dispersed atom catalysts with a high level of metal loading limits their practical applications. Here, a sulphur-doping strategy was proposed to enhance the incorporation of single Pt atoms in monolayer graphitic carbon nitride (g-C3N4), and the structural, electronic and optical properties were investigated through density functional theory (DFT) calculations. This work verified that SACs based on sulphur-doped monolayer g-C3N4 (S-g-C3N4) exhibit a lower band gap energy, higher photocatalytic oxidation ability, easier charge separation, lower oxidation state of Pt atoms and wider light absorption range. This work provides a promising path for fabricating efficient g-C3N4-based photocatalytic SACs.

Post relocation of industrial sites for decades: Ascertain sources and human risk assessment of soil polycyclic aromatic hydrocarbons.

As a persistent organic pollutant, polycyclic aromatic hydrocarbons (PAHs) may still residually pollute industrial sites after relocation. This study investigated the contamination status of PAHs in the topsoils of three industrial legacy sites (the Shougang industrial ruins, the original Beijing coking plant area, and an abandoned gas station) that relocated more than 10 years ago from downtown Beijing. The sources of PAHs in the soil were qualitatively and quantitatively analyzed, and health risks were evaluated for different groups of people. The total concentration of 16 PAHs in the study area ranged from 371.1 ng g-1 to 4073.9 ng g-1. The pollution levels of the three study areas were abandoned gas station > Beijing coking plant > Shougang ruins. In terms of composition, low-ring aromatics accounted for the majority of the detected PAHs, and in the dry season, low-ring aromatics accounted for a higher proportion in the three areas than in the wet season. The comparison of the PAH diagnostic ratio and PMF model verification showed that the sources of PAHs in the Shougang ruins and the Beijing coking plant area were mainly those of biomass and coal combustion, accounting for 66.3% and 56.1% of the total detected PAHs, respectively; the PAH sources of the abandoned gas station storage tank area were largely that of petrol (33.9%) and diesel combustion (23.8%). Since these industrial sites were located in urban centers, this study also conducted a health risk assessment of the topsoil. The total carcinogenic risk range of the three contaminated sites was 1.41E-06 to 2.47E-05. Abandoned industrial sites have potential carcinogenic risks to human health. The government needs to conduct comprehensive risk assessments and remedial measures on soils of industrial legacy sites to achieve land reuse.

Microbial diversity and co-occurrence patterns in deep soils contaminated by polycyclic aromatic hydrocarbons (PAHs).

Numerous studies have enriched our knowledge of the microbial community composition and metabolic versatility of contaminated soil. However, there remains a substantial gap regarding the bioassembly patterns of the indigenous microbial community distribution in contaminated deep soils. Herein, the indigenous microbial community structure diversity, function, and co-occurrence relationships in aged PAH-contaminated deep soil collected from an abandoned chemical facility were investigated using high-throughput sequencing. The results showed that the dominant phyla in all samples were responsible for PAH degradation and included Proteobacteria (20.86%-81.37%), Chloroflexi (2.03%-28.44%), Firmicutes (3.06%-31.16%), Actinobacteria (2.92%-11.91%), Acidobacteria (0.41%-12.68%), and Nitrospirae (0.81%-9.21%). Eighty biomarkers were obtained by linear discriminant analysis of effect size (LEfSe), and most of these biomarkers were PAH degraders. Functional predictions using Tax4Fun indicated that the aged contaminated soil has the potential for PAH degradation. Statistical analysis showed that in contrast with the PAH concentration, edaphic properties (nutrients and pH) were significantly correlated (r > 0.25, P < 0.01) with the bacterial community and functional composition. Co-occurrence network analysis (modularity index of 0.781) revealed non-random assembly patterns of the bacterial communities in the PAH-contaminated soils. The modules in the network were mainly involved in carbon and nitrogen cycles, organic substance degradation, and biological electron transfer processes. Microbes from the same module had strong ecological linkages. Additionally, SAR202 clade, Thermoanaerobaculum, Nitrospira, and Xanthomonadales, which were identified as keystone species, played an irreplaceable role in the network. Overall, our results suggested that environmental factors such as nutrients and pH, together with ecological function, are the main factors driving the assembly of microbial communities in aged PAH-contaminated deep soils.

The effect of low-molecular-weight organic-acids (LMWOAs) on treatment of chromium-contaminated soils by compost-phytoremediation: Kinetics of the chromium release and fractionation.

A soil-plant biological system was developed from chromium (Cr) polluted soil treated by the compost-phytoremediation method. The transformation and migration of the Cr in this system is comprehensively studied in this research. The results illustrated that the co-composting treatment can reduce the Cr availability from 39% (F1 was about 31% of total, F2 was about 8% of total) to less than 2% by stabilizing the Cr. However, herbaceous plants can accumulate the concentrations of Cr from 113.8 to 265.2mg/kg in the two crops, even though the concentration of soluble Cr in the substrate soil was below 0.1mg/L. Cr can be assimilated and easily transferred in the tissues of plants because the low-molecular-weight organic-acids (LMWOAs) derived from the plant root increase the bioavailability of Cr. The amount of extracted Cr dramatically increased when the organic acids were substituted in this order: citric acid>malic acid>tartaric acid>oxalic acid>acetic acid. On average the maximum (147.4mg/kg) and the minimum (78.75mg/kg) Cr were extracted by 20mmol/L citric acid and acetic acid, respectively. The desorption of Cr in different acid solutions can be predicted by the pseudo second-order kinetics. The exchangeable Cr, carbonate-bound Cr, and residual Cr decreased, while Fe-Mn oxide bound Cr and organic bound Cr increased in the soil solid phase. According to the experimental results, the organic acids will promote the desorption and chelation processes of Cr, leading to the remobilization of Cr in the soil.

iTRAQ-based proteomic profiling of a Microbacterium sp. strain during benzo(a)pyrene removal under anaerobic conditions.

This study focused on the protein expression of a Microbacterium sp. strain that utilized various concentrations of benzo(a)pyrene (BaP) as the sole source of carbon and energy under anaerobic conditions. A total of 1539 protein species were quantified by isobaric tags for relative and absolute quantitation (iTRAQ) coupled with LC-MS/MS. GO, COG, and pathway enrichment analysis showed that most proteins demonstrated catalytic and binding functions and were mainly involved in metabolic processes, cellular processes, and single-organism processes. Sixty-two proteins were found in their abundances in BaP-stress conditions different from normal conditions. These proteins function in the metabolic pathways; the biosynthesis of secondary metabolites, the biosynthesis of antibiotics, microbial metabolism in diverse environments, carbon metabolism, and the biosynthesis of amino acids were markedly altered. Furthermore, enoyl-CoA hydratase was proposed to be a key protein during BaP removal of the Microbacterium sp. strain. This study provides a powerful platform for the further exploration of BaP removal, and the differentially expressed proteins provide insight into the mechanism of the BaP removal pathway.

Comparative proteomic analysis and characterization of benzo(a)pyrene removal by Microbacterium sp. strain M.CSW3 under denitrifying conditions.

High-molecular-weight polycyclic aromatic hydrocarbons are persistent organic pollutants with great environmental and human health risks and the associated bioremediation activities have always been hampered by the lack of powerful bacterial species under redox conditions. A Microbacterium sp. strain capable of using benzo(a)pyrene as sole carbon and energy sources under denitrifying conditions was isolated. The difference in protein expression during BaP removal and removal characterization were investigated. A total of 146 proteins were differentially expressed, 44 proteins were significantly up-regulated and 102 proteins were markedly down-regulated. GO and COG analysis showed that BaP removal inhibited the expression of proteins related to glucose metabolism at different levels and activated other metabolic pathway. The proteins associated with catalytic activity and metabolic process were altered significantly. Furthermore, the BaP removal might be occurred in certain organelle of M.CSW3. The strain removed BaP with a speed of 0.0657-1.0072 mg/L/day over the concentrations range 2.5-100 mg/L. High removal rates (>70%) were obtained over the range of pH 7-11 in 14 days. Carbohydrates and organic acids which could be utilized by the strain, as well as heavy metal ions, reduced BaP removal efficiency. However, phenanthrene or pyrene addition enhanced the removal capability of M.CSW3. The strain was proved to have practical potential for bioremediation of PAHs-contaminated soil and this study provided a powerful platform for further application by improving production of associated proteins.

Removal of Cs+ from water and soil by ammonium-pillared montmorillonite/Fe3O4 composite.

To remove cesium ions from water and soil, a novel adsorbent was synthesized by following a one-step co-precipitation method and using non-toxic raw materials. By combining ammonium-pillared montmorillonite (MMT) and magnetic nanoparticles (Fe3O4), an MMT/Fe3O4 composite was prepared and characterized. The adsorbent exhibited high selectivity of Cs+ and could be rapidly separated from the mixed solution under an external magnetic field. Above all, the adsorbent had high removal efficiency in cesium-contaminated samples (water and soil) and also showed good recycling performance, indicating that the MMT/Fe3O4 composite could be widely applied to the remediation of cesium-contaminated environments. It was observed that the pH, solid/liquid ratio and initial concentration affected adsorption capacity. In the presence of coexisting ions, the adsorption capacity decreased in the order of Ca2+>Mg2+>K+>Na+, which is consistent with our theoretical prediction. The adsorption behavior of this new adsorbent could be expressed by the pseudo-second-order model and Freundlich isotherm. In addition, the adsorption mechanism of Cs+ was NH4+ ion exchange and surface hydroxyl group coordination, with the former being more predominant.

A study of subsurface wastewater infiltration systems for distributed rural sewage treatment.

Three types of subsurface wastewater infiltration systems (SWIS) were developed to study the efficiency of organic pollutant removal from distributed rural sewage under various conditions. Of the three different layered substrate systems, the one with the greatest amount of decomposed cow dung (5%) and soil (DCDS) showed the highest removal efficiency with respect to total nitrogen (TN), where the others showed no significant difference. The TN removal efficiency was increased with an increasing filling height of DCDS. Compared with the TN removal efficiency of 25% in the system without DCDS, the removal efficiency of the systems in which DCDS filled half and one fourth of the height was increased by 72% and 31%, respectively. Based on seasonal variations in the discharge of the typical rural family, the SWIS were run at three different hydraulic loads of 6.5, 13 and 20 cm/d. These results illustrated that SWIS could perform well at any of the given hydraulic loads. The results of trials using different inlet configurations showed that the effluent concentration of the contaminants in the system operating a multiple-inlet mode was much lower compared with the system operated under single-inlet conditions. The effluent concentration ofa pilot-scale plant achieved the level III criteria specified by the Surface Water Quality Standard at the initial stage.

Bibliometric insights into the evolution of uranium contamination reduction research topics: Focus on microbial reduction of uranium.

Confronting the threat of environment uranium pollution, decades of research have yielded advanced and significant findings in uranium bioremediation, resulting in the accumulation of tremendous amount of high-quality literature. In this study, we analyzed over 10,000 uranium reduction-related papers published from 1990 to the present in the Web of Science based on bibliometrics, and revealed some critical information on knowledge structure, thematic evolution and additional attention. Methods including contribution comparison, co-occurrence and temporal evolution analysis are applied. The results of the distribution and impact analysis of authors, sources, and journals indicated that the United States is a leader in this field of research and China is on the rise. The top keywords remained stable, primarily focused on chemicals (uranium, iron, plutonium, nitrat, carbon), characters (divers, surfac, speciat), and microbiology (microbial commun, cytochrome, extracellular polymeric subst). Keywords related to new strains, reduction mechanisms and product characteristics demonstrated the strongest uptrend, while some keywords related to mechanism and performance were clearly emerging in the past 5 years. Furthermore, the evolution of the thematic progression can be categorized into three stages, commencing with the discovery of the enzymatic reduction of hexavalent uranium to tetravalent uranium, developing in the groundwater remediation process at uranium-contaminated sites, and delving into the research on microbial reduction mechanisms of uranium. For future research, enhancing the understanding of mechanisms, improving uranium removal performance, and exploring practical applications can be considered. This study provides unique insights into microbial uranium reduction research, providing valuable references for related studies in this field.

Nitrogen-doped carbon materials prepared using different organic precursors as catalysts of peroxymonosulfate to degrade sulfamethoxazole: First-time performance leading to the incorrect selection of the best catalyst.

Nitrogen-doped carbon materials are effective catalysts for peroxymonosulfate (PMS) activation to eliminate organic contaminants. In this research, the activity of nitrogen-doped carbon materials was significantly improved by optimizing the carbon source, and the reusability of the catalyst is used to select the best catalyst instead of depending on the performance in the first use, for avoiding the "short-life" catalyst with great initial activity. Fixing ferric nitrate nonahydrate and melamine as the metal and nitrogen sources, four catalysts were prepared using glucose, glucosamine hydrochloride, dopamine, and trimesic acid as the carbon sources, respectively. Based on the performance in PMS activation for sulfamethoxazole (SMX) removal, in the first use, the activity was Fe-DA-CN (carbon source: dopamine) > Fe-BTC-CN (carbon source: trimesic acid) > Fe-GLU-CN (carbon source: glucosamine) > Fe-DGLU-CN (carbon source: glucose). With no washing for the second time use, the activity was Fe-BTC-CN (0.135 min-1) â‰« Fe-DA-CN (0.037 min-1) > Fe-GLU-CN (0.032 min-1) > Fe-DGLU-CN (0.017 min-1). The large specific surface area, superior graphitization, and high CO/C-N group content endow Fe-BTC-CN with high ability in PMS activity. Surface-bound radicals are responsible for SMX elimination, and most of the SMX degradation intermediates have lower ecotoxicity than SMX.

A Multiplex Quantitative Polymerase Chain Reaction for the Rapid Differential Detection of Subgroups A, B, J, and K Avian Leukosis Viruses.

Avian leukosis (AL), caused by avian leukosis virus (ALV), is a contagious tumor disease that results in significant economic losses for the poultry industry. Currently, ALV-A, B, J, and K subgroups are the most common in commercial poultry and cause possible coinfections. Therefore, close monitoring is necessary to avoid greater economic losses. In this study, a novel multiplex quantitative polymerase chain reaction (qPCR) assay was developed to detect ALV-A, ALV-B, ALV-J, and ALV-K with limits of detection of 40, 11, 13.7, and 96 copies/µL, respectively, and no cross-reactivity with other ALV subtypes and avian pathogens. We detected 852 cell cultures inoculated with clinical samples using this method, showing good consistency with conventional PCR and ELISA. The most prevalent ALV strain in Hubei Province, China, was still ALV-J (11.74%). Although single infections with ALV-A, ALV-B, and ALV-K were not found, coinfections with different subgroup strains were identified: 0.7% for ALV-A/J, 0.35% for ALV-B/J, 0.25% for ALV-J/K, and 0.12% for ALV-A/B/K and ALV-A/B/J. Therefore, our novel multiplex qPCR may be a useful tool for molecular epidemiology, clinical detection of ALV, and ALV eradication programs.

Response of the soil microbial community to petroleum hydrocarbon stress shows a threshold effect: research on aged realistic contaminated fields.

Introduction: Microbes play key roles in maintaining soil ecological functions. Petroleum hydrocarbon contamination is expected to affect microbial ecological characteristics and the ecological services they provide. In this study, the multifunctionalities of contaminated and uncontaminated soils in an aged petroleum hydrocarbon-contaminated field and their correlation with soil microbial characteristics were analyzed to explore the effect of petroleum hydrocarbons on soil microbes. Methods: Soil physicochemical parameters were determined to calculate soil multifunctionalities. In addition, 16S high-throughput sequencing technology and bioinformation analysis were used to explore microbial characteristics. Results: The results indicated that high concentrations of petroleum hydrocarbons (565-3,613 mg•kg-1, high contamination) reduced soil multifunctionality, while low concentrations of petroleum hydrocarbons (13-408 mg•kg-1, light contamination) might increase soil multifunctionality. In addition, light petroleum hydrocarbon contamination increased the richness and evenness of microbial community (p < 0.01), enhanced the microbial interactions and widened the niche breadth of keystone genus, while high petroleum hydrocarbon contamination reduced the richness of the microbial community (p < 0.05), simplified the microbial co-occurrence network, and increased the niche overlap of keystone genus. Conclusion: Our study demonstrates that light petroleum hydrocarbon contamination has a certain improvement effect on soil multifunctionalities and microbial characteristics. While high contamination shows an inhibitory effect on soil multifunctionalities and microbial characteristics, which has significance for the protection and management of petroleum hydrocarbon-contaminated soil.

Virulent Phage vB_EfaS_WH1 Removes Enterococcus faecalis Biofilm and Inhibits Its Growth on the Surface of Chicken Meat.

Enterococcus faecalis is a potential animal and human pathogen. Improper use of antibiotics encourages resistance. Bacteriophages and their derivatives are promising for treating drug-resistant bacterial infections. In this study, phylogenetic and electron microscopy analyses of phage vB_EfaS_WH1 (WH1) isolated from chicken feces revealed it to be a novel phage in the family Siphoviridae. WH1 showed good pH stability (4-11), temperature tolerance (4-60 °C), and broad E. faecalis host range (60% of isolates). Genome sequencing revealed a 56,357 bp double-stranded DNA genome with a G+C content of 39.21%. WH1 effectively destroyed E. faecalis EF01 biofilms, even at low concentrations. When WH1 was applied at 1 × 105 to 1 × 109 PFU/g to chicken breast samples stored at 4 °C, surface growing E. faecalis were appreciably eradicated after 24 h. The phage WH1 showed good antibacterial activity, which could be used as a potential biocontrol agent to reduce the formation of E. faecalis biofilm, and could also be used as an alternative for the control of E. faecalis in chicken products.

A screen-printed, amperometric biosensor for the determination of organophosphorus pesticides in water samples.

An amperometric biosensor based on screen-printed electrodes (SPEs) was developed for the determination of organophosphorus pesticides in water samples. The extent of acetylcholinesterase (AChE) deactivation was determined and quantified for pesticide concentrations in water samples. An enzyme immobilization adsorption procedure and polyacrylamide gel matrix polymerization were used for fabrication of the biosensor, with minimal losses in enzyme activity. The optimal conditions for enzyme catalytic reaction on the SPEs surfaces were acetylthiocholine chloride (ATChCl) concentration of 5 mmol/L, pH 7 and reaction time of 4 min. The detection limits for three organophosphorus pesticides (dichlorvos, monocrotophs and parathion) were in the range of 4 to 7 microg/L when an AChE amount of 0.1 U was used for immobilization.