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Remediation of mercury (Hg)-contaminated soil by mycorrhizal technology has drawn increasing attention because of its environmental friendliness. However, the lack of systematic investigations on arbuscular mycorrhizal fungi (AMF) community composition in Hg-polluted soil is an obstacle for AMF biotechnological applications. In this study, the AMF communities within rhizosphere soils from seven sites from three typical Hg mining areas were sequenced using an Illumina MiSeq platform. A total of 297 AMF operational taxonomic units (OTUs) were detected in the Hg mining area, of which Glomeraceae was the dominant family (66.96%, 175 OTUs). AMF diversity was significantly associated with soil total Hg content and water content in the Hg mining area. Soil total Hg showed a negative correlation with AMF richness and diversity. In addition, the soil properties including total nitrogen, available nitrogen, total potassium, total phosphorus, available phosphorus, and pH also affected AMF diversity. Paraglomeraceae was found to be negatively correlated to Hg stress. The wide distribution of Glomeraceae in Hg-contaminated soil makes it a potential candidate for mycorrhizal remediation. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are widely present in aquatic environments, causing harm to aquatic organisms and posing a threat to human health. MP risk assessment has therefore attracted increasing attention; yet few studies have been conducted on the water quality criteria (WQC) of MPs in the surface waters of China. Herein, data on the toxicity of MPs in aquatic species were reviewed, and the species sensitivity distribution (SSD) method was employed to determine the WQC for the protection of aquatic organisms against MP pollution. Criteria included the maximum concentration (CMC) and the continuous concentration (CCC). In addition, the ecological risk posed by MPs in China's main aquatic systems was assessed using a probabilistic method. The CMC and CCC were estimated at 59.42 μg/L (1.67 × 107 particles/M3) and 93.94 μg/L (2.90 × 105 particles/M3), respectively. The ecological risk levels of MP pollution across the seven aquatic systems in China were as follows: Yangtze, Pearl, Yellow, SongHua, LiaoHe, HaiHe, and HuaiHe Rivers. Although the average concentrations of seven rivers are all far lower than the CCC and CMC values obtained in this study, MP pollution might have harmful effects on aquatic organisms in some regions, necessitating tighter water quality management with regard to MPs in the future. Species sensitivity distribution (SSD) curves were established using microplastic (MP) toxicity data. The criteria maximum concentration (CMC) and criteria continuous concentration (CCC) of MPs for protection of aquatic organisms were derived. A probabilistic method was used to assess the ecological risk of MPs in major Chinese river systems. MP pollution might harm aquatic organisms in certain regions. [ABSTRACT FROM AUTHOR]

The concentrations of PAHs in four species of fish (Common carp, Crucian carp, Bighead carp, and Topmouth culter) from Lake Taihu were tested, and the human health risks of PAHs by fish consumption were evaluated. Results showed that concentrations of PAHs in fish from Lake Taihu were 52.5–247.6 ng/g wet weight (ww), and the BaP equivalent concentrations of total PAHs (B[a]Peq) were 0.2–0.6 ng/g ww, which were less than the screening value of 2.6 ng/g wet for human consumption. The concentration sequences of PAHs in fish from Lake Taihu from high to low were Bighead carp > Crucian carp > Common carp > Topmouth culter. The human health risk level of PAHs by fish consumption was 5.8 ± 2.5 × 10−6, which was less than the maximum acceptable risk level of 1 × 10−5for human health set by the U.S. Environmental Protection Agency. The tissue residue guideline (TRG) of PAHs for protecting aquatic wildlife was 1.3 mg/kg diet ww, which was higher than the concentrations of PAHs in fish from Lake Taihu. The results indicated that fish consumption from Lake Taihu would not cause health risk or harmful effects on wildlife that consume aquatic biota. [ABSTRACT FROM PUBLISHER]

Establishment of water quality criteria (WQC) is one procedure for protection of marine organisms and their ecosystems. This study, which integrated two separate approaches, quantitative ion character-activity relationships (QICARs) and species sensitivity distributions (SSDs), developed a novel QICAR-SSD model. The QICARs predict relative potencies of individual elements while SSDs integrate relative sensitivities among organisms. The QICAR-SSD approach was applied to derive saltwater WQC for 34 metals or metalloids. Relationships between physicochemical properties of metal ions and their corresponding potencies for acute toxicity to eight selected marine species were determined. The softness index (σp) exhibited the strongest correlation with the acute toxicity of metals (r > 0.66, F > 5.88, P < 0.94 × 10). Predictive criteria maximum concentrations for the eight metals, derived by applying the SSD approach to values predicted by use of QICARs, were within the same order of magnitude as values recommended by the US EPA (). In general, the results support that the QICAR-SSD approach is a rapid method to estimate WQC for metals for which little or no information is available for marine organisms. [ABSTRACT FROM AUTHOR]

The epiphytic bacteria in aquatic ecosystems, inhabiting a unique ecological niche with significant ecological function, have long been the subject of attention. Habitat characteristics and plant species are believed to be important in controlling the assembly of epiphytic bacteria. However, the underlying principle governing the assembly of the epiphytic bacterial community on macrophytes is far from clear. In this study, we systematically compared the diversity and community composition of epiphytic bacteria both in different habitats and on different species of macrophytes where they were attached. Results suggested that neither the plant species nor the habitat had a significant effect on the diversity and community of epiphytic bacteria independently, indicating that the epiphytic bacterial community composition was correlated to both geographical distance and individual species of macrophytes. Furthermore, almost all of the abundant taxa were shared between different lake regions or macrophyte species, and the most abundant bacteria belonged to Proteobacteria and Firmicutes. Our results demonstrated that the competitive lottery model may explain the pattern of epiphytic bacterial colonization of submerged macrophyte surfaces. This research could provide a new perspective for exploring plant-microbe interaction in aquatic systems and new evidence for the lottery model as the mechanism best explaining the assembly of epiphytic bacteria., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Fang, Zhen, Yang, Su and Wei.)

The mainstream approach to antiviral drugs against COVID-19 is to focus on key stages of the SARS-CoV-2 life cycle. The vast majority of candidates under investigation are repurposed from agents of other indications. Understanding protein-inhibitor interactions at the molecular scale will provide crucial insights for drug discovery to stop this pandemic. In this article, we summarize and analyze the most recent structural data on several viral targets in the presence of promising inhibitors for COVID-19 in the context of the perspective of modes of action (MOA) to unravel insightful mechanistic features with atomistic resolution. The targets include spike glycoprotein and various host proteases mediating the entry of the virus into the cells, viral chymotrypsin- and papain-like proteases, and RNA-dependent RNA polymerase. The main purpose of this review is to present detailed MOA analysis to inspire fresh ideas for both de novo drug design and optimization of known scaffolds to combat COVID-19., (© 2020 Wiley-VCH GmbH.)