This study aims to investigate the effects of long-term nicosulfuron residue on an herbicide factory ecosystem. High-throughput sequencing was used to investigate the environmental microbial community structure and interactions. The results showed that the main contributor to the differences in the microbial community structure was the sample type, followed by oxygen content, pH and nicosulfuron residue concentration. Regardless of the presence or absence of nicosulfuron, soil, sludge, and sewage were dominated by groups of Bacteroidetes, Actinobacteria, and Proteobacteria. Long-term exposure to nicosulfuron increased alpha diversity of bacteria and archaea but significantly decreased the abundance of Bacteroidetes and Acidobateria compared to soils without nicosulfuron residue. A total of 81 possible nicosulfuron-degrading bacterial genera, e.g., Rhodococcus, Chryseobacterium, Thermomonas, Stenotrophomonas, and Bacillus, were isolated from the nicosulfuron factory environmental samples through culturomics. The co-occurrence network analysis indicated that the keystone taxa were Rhodococcus, Stenotrophomonas, Nitrospira, Terrimonas, and Nitrosomonadaceae_MND1. The strong ecological relationship between microorganisms with the same network module was related to anaerobic respiration, the carbon and nitrogen cycle, and the degradation of environmental contaminants. Synthetic community (SynCom), which provides an effective top-down approach for the critical degradation strains obtained, enhanced the degradation efficiency of nicosulfuron. The results indicated that Rhodococcus sp. was the key genus in the environment of long-term nicosulfuron exposure.

Traditional soil heavy metal (HM) investigation usually costs a lot of human and material resources. In-situ portable X-ray fluorescence spectrometry (PXRF) is a cheap and rapid HM analysis method, but its analysis accuracy is usually affected by spatially non-stationary field environment factors. In this study, residual sequential Gaussian co-simulation (RCoSGS) was first proposed to incorporate both continuous and categorical auxiliary variables for spatial simulation of soil Cu. Next, additional in-situ PXRF sampling sites (n = 300) were allocated in the subareas with high, medium, and low conditional variances in the proportions of 50%, 33.33%, and 16.67%, respectively. Then, robust geographically weighted regression (RGWR) was established to correct the spatially non-stationary effects of field environmental factors on in-situ PXRF and further compared with the traditionally-used multiple linear regression (MLR) and basic GWR in correction accuracy. Finally, RCoSGS with the RGWR-corrected in-situ PXRF as part of hard data (RCoSGS-PXRF) was established and further compared with the model with one or multiple auxiliary variables in the spatial simulation accuracy. Results showed that (i) RCoSGS effectively incorporated both SOM and land-use types and obtained higher spatial simulation accuracy (RI = 37.52%) than residual sequential Gaussian simulation with land-use types (RI = 19.44%) and sequential Gaussian co-simulation with SOM (RI = 20.92%); (ii) RGWR significantly weakened the spatially non-stationary effects of field environmental factors on in-situ PXRF, and RGWR (RI = 58.96%) and GWR (RI = 39.61%) obtained higher correction accuracy than MLR; (iii) the RGWR-corrected in-situ PXRF (RI = 66.57%) brought higher spatial simulation accuracy than both land-use types and SOM (RI = 37.52%); (iv) RCoSGS-PXRF obtained the highest spatial simulation accuracies (RI = 83.74%). Therefore, the proposed method is cost-effective for the rapid and high-precision investigation of soil HMs at a regional scale.

In recent decades, nanotechnology has rapidly developed. Therefore, there is growing concern about the potential environmental risks of nanoparticles (NPs). Caenorhabditis elegans (C. elegans) has been used as a powerful tool for studying the potential ecotoxicological impacts of nanomaterials from the whole animal level to single cell level, especially in the area of reproduction. In this review, we discuss the reproductive toxicity of common nanomaterials in C. elegans, such as metal-based nanomaterial (silver nanoparticles (NPs), gold NPs, zinc oxide NPs, copper oxide NPs), carbon-based nanomaterial (graphene oxide, multi-walled carbon nanotubes, fullerene nanoparticles), polymeric NPs, silica NPs, quantum dots, and the potential mechanisms involved. This insights into the toxic effects of existing nanomaterials on the human reproductive system. In addition, we summarize how the physicochemical properties (e.g., size, charge, surface modification, shape) of nanomaterials influence their reproductive toxicity. Overall, using C. elegans as a platform to develop rapid detection techniques and prediction methods for nanomaterial reproductive toxicity is expected to reduce the gap between biosafety evaluation of nanomaterials and their application.

The presence of microplastics in oceans and coastlines has increased during recent years due anthropogenic activities and represents a serious environmental problem. The establishment and assembly of microbial communities in these microplastics, specifically located near aquaculture activities, is not well understood. In this study, we analyzed unique and core members of bacterial communities attached to microplastics collected from three coastal environments of the South Pacific, which represent low, medium and high anthropogenic activity derived from the aquaculture industry. Microplastics were analyzed with Fourier-transform infrared spectroscopy, scanning electron microscopy, and next-generation sequencing to assess the prevailing microplastics types, and to characterize microbial communities attached to them. We identified four main types of microplastics (polypropylene, polyethylene, nylon and polystyrene) and 3102 Operational Taxonomic Units (OTUs) at the sampled sites, which were dominated by the phylum Cyanobacteria, Bacteroidetes and Proteobacteria (mainly Alpha and Gammaproteobacteria). Similarity index analysis showed that bacterial communities in microplastics differed from those found in the surrounding seawaters, and also that they varied among locations, suggesting a role of the environment and level of anthropogenic activities on the plastisphere taxa. Despite this difference, 222 bacterial OTUs were shared among the three sites representing between 34 and 51% of OTUs of each sampled site, and thus constituted a core microbiome of microplastics. Comparison of the core microbiome with bacterial communities of the surrounding seawater suggested that the plastisphere constituted a selective habitat for diverse microbial communities. Computational predictions also provided evidence of significantly enriched functions in the core microbiome. Co-occurrence networks revealed that putative ecological interactions among microplastics OTUs was dominated by positive correlations. To the best of our knowledge, this is the first study that evaluated the composition of microbial communities found in microplastics from the Patagonia region of the Southern Pacific Ocean.

The aquaculture industry is considered a key sector for the supply of high quality, nutritious food. However, growth of the aquaculture sector has been slow, particularly in Europe, and this is amongst others linked to concerns about environmental impacts of this industry. Integrated Multitrophic Aquaculture (IMTA) has been identified as an important technology to sustainably improve freshwater fish production. In IMTA, economically valuable extractive species feed on waste produced by other species, remediating wastewater, and minimising the environmental impact of aquaculture. This study presents quantitative information on the nitrogen and phosphorus removal efficiency of a duckweed-based, pilot, semi-commercial IMTA system. Duckweed species are free-floating freshwater species belonging to the family of Lemnaceae. The aim of this study was to test the potential of duckweed-based IMTA under realistic environmental conditions. Three different approaches were used to assess remediation capacity; 1) assessment of water quality pre and post treatment with duckweed showed that the system can remove 0.78 and 0.38 T y⁻¹ of Total Nitrogen (TN) and Total Phosphorus (TP), respectively 2) based on nitrogen and phosphorus content of newly grown duckweed biomass, it was shown that 1.71 and 0.22 T y⁻¹ of TN and TP can be removed, respectively 3) extrapolation based on laboratory established nitrogen and phosphorus uptake rates determined that 0.88 and 0.08 T y⁻¹ of TN and TP can be removed by the system. There is substantive agreement between the three assessments, and the study confirms that duckweed can maintain good quality water in an IMTA system, while yielding high protein content (21.84 ± 2.45%) biomass. The quantitative data on nitrogen and phosphorus removal inform the design of further IMTA systems, and especially create a scientific basis to determine the balance between aquaculture and extractive species.

Marine debris is now a ubiquitous component of the Anthropocene global ocean. Plastic ingestion by marine wildlife was first reported in the 1960s and since that time, roughly one thousand marine species have been reported to consume this debris. This study focuses on plastic ingestion by marine invertebrates and vertebrates in the North Pacific Ocean. Specifically, we reviewed the scientific literature to assess the scope of the problem, identified key bioindicator species, and proposed guidelines for future monitoring of plastic debris in North Pacific marine ecosystems. Our meta-analysis confirmed that the North Pacific is among the most polluted ocean regions globally; roughly half of all fish and seabird specimens and more than three-quarters of sea turtles and bivalve specimens examined in this region had consumed plastic. While there are not enough standardized data to assess if these ingestion rates are changing, sampling standardization and reporting of methods are improving over time. Using a rubric-evaluation approach, we evaluated 352 species for their potential to serve as bioindicators of the prevalence of plastic pollution in the North Pacific. This analysis revealed a suite of 12 bioindicator species candidates which sample a variety of ecosystem components and cover a wide range of plastic size classes. Thus, we contend that these bioindicator candidates provide a key foundation for developing a comprehensive plastic monitoring program in the region. To enhance the utility of these bioindicators, we developed a framework for standardized data collection to minimize methodological variability across different studies and to facilitate the assessment of temporal trends over space and time. Tracking plastic ingestion by these bioindicators will help to assess the effectiveness of mitigation actions in the region, a critical step to evaluate progress towards sustainability and improved ocean health in the 21st century.

Co-pyrolysis of sewage sludge (SL) with plant biomass gains attention as a way to minimize SL-derived biochar drawbacks, such as high amount of toxic substances, low specific surface area and carbon content. The toxicity of soil amended with SL- (BCSL) or SL/biomass (BCSLW)-derived biochar was evaluated in long-term pot experiment (180 days). The results were compared to SL-amended soil. Biochars produced at 500, 600, or 700 °C were added to the soil (podzolic loamy sand) at a 2% (w/w) dose. Samples were collected at four different time points (at the beginning, after 30, 90 and 180 days) to assess the potential toxicity of SL-, BCSL- or BCSLW-amended soil. The bacteria Aliivibrio fischeri (luminescence inhibition – Microtox), the plant Lepidium sativum (root growth and germination inhibition test – Phytotoxkit F), and the invertebrate Folsomia candida (mortality and reproduction inhibition test – Collembolan test) were used as the test organisms. Depending on the organism tested and the sample collection time point variable results were observed. In general, SL-amended soil was more toxic than soil with biochars. The leachates from BCSLW-amended soil were more toxic to A. fischeri than leachate from BCSL-amended soil. A different tendency was observed in the case of phytotoxicity. Leachate from BCSL-amended soil was more toxic to L. sativum compared to BCSLW-amended soil. The effect of biochars on F. candida was very diversified, which did not allow a clear trend to be observed. The toxic effect of SL-, BCSL- or BCSW-amended soil to particular organisms was observed in different time, point's periods, which may suggest the different factors affecting this toxicity.

Marine microplastics (MPs) pose a risk to human health through accumulation in maricultural organisms, particularly bivalves. Various studies have reported the presence of MP particles in Pacific oysters (Crasostrea gigas). In this study, we investigated the size-specific ingestion and egestion of polystyrene (PS) MPs by Pacific oysters. The cultivation density of C. gigas was maintained at 1 L of filtered seawater per oyster (n = 5) during the MP ingestion and egestion experiments. On exposure to 300 n/L of PS MP fragments for 7 d, 60.4% of the PS was ingested within 6 h (7.25 × 10² ± 1.36 × 10² n/indv.), and the ingestion was saturated at 12 h (1.2 × 10³ ± 2.2 × 10² n/indv.) in C. gigas. The maximum MP ingestion capacity (Igₘₐₓ) of a single Pacific oyster was 73.0 ± 16.3 n/g wet weight. Further, 62.9% of the PS MP particles were egested for 7 d from the saturated single C. gigas. Ingestion and egestion varied according to the PS MP size. In the case of <50 μm PS MP, ingestion rate was low but MP amount and net-ingestion efficiency was significantly higher than other PS MP sizes. In addition, egestion, egestion rate, and net-egestion efficiency for <50 μm PS MPs were significantly higher than other PS MP sizes. Therefore, smaller MPs (<50 μm) normally exhibit the highest ingestion and egestion rates; therefore, the 50–300 μm size fraction exhibited the highest residual possibility (particles >1000 μm were excluded). Additionally, considering the net-egestion efficiency, the most economical and efficient depuration period was 24 h. This study clarifies the size-specific MP accumulation in oysters, and the egestion results suggest that the potential risk of MPs to human health through the intake of maricultural products could be reduced by depuration.

The presence of heavy metals in municipal solid waste (MSW) is considered as prevalent global pollutants that cause serious risks to the environment and living organisms. Due to industrial and anthropogenic activities, the accumulation of heavy metals in the environmental matrices is increasing alarmingly. MSW causes several adverse environmental impacts, including greenhouse gas (GHG) emissions, river plastic accumulation, and other environmental pollution. Indigenous microorganisms (Pseudomonas, Flavobacterium, Bacillus, Nitrosomonas, etc.) with the help of new pathways and metabolic channels can offer the potential approaches for the treatment of pollutants. Microorganisms, that exhibit the ability of bioaccumulation and sequestration of metal ions in their intracellular spaces, can be utilized further for the cellular processes like enzyme signaling, catalysis, stabilizing charges on biomolecules, etc. Microbiological techniques for the treatment and remediation of heavy metals provide a new prospects for MSW management. This review provides the key insights on profiling of heavy metals in MSW, tolerance of microorganisms, and application of indigenous microorganisms in bioremediation. The literatures revealed that indigenous microbes can be exploited as potential agents for bioremediation.

Both cancer and diabetes mellitus are serious health issues, accounting more than 11 million deaths worldwide annually. Targeted use of plant-mediated nanoparticles (NPs) in treatment of ailments has outstanding results due to their salient properties. The current study was designed to investigate the safe production of silver nanoparticles (AgNPs) from Acacia nilotica. Different concentrations of AgNO₃ were tested to optimize the protocol for the synthesis of AgNPs from the bark extract. It was demonstrated that 0.1 M and 3 mM were found to be the optimum concentrations for the synthesis of AgNPs. Standard characterization techniques such as UV–vis spectrophotometry, SEM, SEM-EDX micrograph, spot analysis, elemental mapping and XRD were used for the conformation of biosynthesis of AgNPs. Absorption spectrum of plant-mediated AgNPs under UV–vis spectrophotometer showed a strong peak at 380 nm and 420 nm for AgNPs synthesized at 0.1 M and 3 mM concentration of salt. The SEM results showed that AgNPs were present in variable shapes within average particle size ranging from (20–50 nm). Anticancer, antidiabetic and antioxidant potential of green AgNPs was investigated and they showed promising results as compared to the positive and negative controls. Hence, AgNPs were found potent therapeutic agent against the human liver cancer cell lines (HepG2), strong inhibitor for α-glucosidase enzyme activity and scavenging agent against free radicals that cause oxidative stress. Further studies are however needed to confirm the molecular mechanism and biochemical reactions responsible for the anticancer and antidiabetic activities of the particles.