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1.
J Environ Manage ; 360: 121121, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38744204

ABSTRACT

Despite much progress has been made in the evaluation of ecological restoration outcomes, there is still a lack of a suitable framework for evaluating the ecological restoration outcomes of urban green space. In view of this, this study systematically analyzed the characteristics and differences between the evaluation index systems of ecological restoration outcome and urban green space quality evaluation, and then discussed the relationship between objective elements of landscape and people's subjective feelings. On this basis, an ecological restoration outcome evaluation framework was developed for urban green space considering people's subjective feelings. It was found that the existing studies of ecological restoration outcome evaluation mainly focused on the change of ecological components and structure, while urban green space environmental quality evaluation on the cultural services. Common ecological components and structure and people's subjective feelings were not all synergy or trade-off relations, in fact, there were still cases of trade-off and synergy relations co-existing. Therefore, a framework was constructed for evaluating the ecological restoration outcome of urban green space, including ecological components and structure, ecological services, social services, and people's subjective feelings.

2.
Sci Total Environ ; 929: 172503, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38631628

ABSTRACT

The aquatic ecosystem, a repository for various pollutants, has been identified as a crucial zone where microplastics (MPs) serve as vectors for antibiotics, facilitating their spread. Despite this, the influence of MPs on the toxicity of antibiotics remains a topic of debate. In this study, we conduct a global meta-analysis, examining 730 datasets from 29 laboratory studies. Our findings reveal that the impact of MPs on antibiotic toxicity is highly dependent on biological response pathways, microplastic concentration, antibiotic properties, and exposure time. We observed that MPs amplify the accumulation of antibiotics in aquatic organisms, significantly heightening their adverse effects on growth, development, and immune functions. Intriguingly, MPs appear to mitigate the reproductive toxicity caused by antibiotics. A notable inverse relationship was identified between antibiotic toxicity and microplastic concentration and exposure time. Furthermore, antibiotic concentration predominantly affects growth, development, and reproductive health, whereas exposure time is critical in determining antibiotic accumulation and immune-related toxicity. These insights underscore that microplastic co-exposure can modify the toxicological profile of antibiotics. The outcomes of this research enhance our comprehensive understanding of the intricate combined effects of MPs and antibiotics on aquatic life, emphasizing the necessity for informed scientific management of these emerging contaminants.


Subject(s)
Anti-Bacterial Agents , Microplastics , Water Pollutants, Chemical , Microplastics/toxicity , Water Pollutants, Chemical/toxicity , Water Pollutants, Chemical/analysis , Anti-Bacterial Agents/toxicity , Aquatic Organisms/drug effects , Ecosystem , Environmental Monitoring
3.
J Hazard Mater ; 469: 134053, 2024 May 05.
Article in English | MEDLINE | ID: mdl-38508111

ABSTRACT

The combined pollution of microplastics (MPs) and arsenic (As) in paddy soils has attracted more attention worldwide. However, there are few comparative studies on the effects of biodegradable and conventional MPs on As migration and transformation. Therefore, conventional (polystyrene, polyethylene, polyvinyl chloride) and biodegradable (polybutadiene styrene, polylactic acid, polybutylene adipate terephthalate) MPs were selected to explore and demonstrate their influences and mechanism on As migration from paddy soils to overlying water and As speciation transformation through microcosmic experiment with measuring the changes of As chemical distribution, physicochemical indexes and microbial community in paddy soils. The results showed that biodegradable MPs enhanced As migration and transformation more effective than conventional MPs during 60 d. Biodegradable MPs indirectly increased the content of As(Ⅲ) and bioavailable As by changing the microbial community structure and affecting the biogeochemical cycles of carbon, nitrogen, sulfur and iron in soils, and promoted the As migration and transformation. PBS showed the strongest promoting effect, transforming to more As(Ⅲ) (11.43%) and bioavailable As (4.28%) than control. This helps to a better understanding of the effects of MPs on As biogeochemical cycle and to clarify the ecological and food safety risks of their combined pollution in soils.


Subject(s)
Arsenic , Arsenic/toxicity , Microplastics/toxicity , Plastics , Polyethylene , Carbon , Soil
4.
Sci Total Environ ; 912: 168743, 2024 Feb 20.
Article in English | MEDLINE | ID: mdl-38007124

ABSTRACT

Though recombinant strains are increasingly recognized for their potential in heavy metal remediation, few studies have evaluated their safety. Moreover, biosafety assessments of fecal-oral pathway exposure at country as well as global level have seldom analyzed the health risks of exposure to microorganisms from a microscopic perspective. The present study aimed to predict the long-term toxic effects of recombinant strains by conducting a subacute toxicity test on the chromium-removal recombinant strain 3458 and analyzing the gut microbiome. The available disinfection methods were also evaluated. The results showed that strain 3458 induced liver damage and affected renal function and lipid metabolism at 1.0 × 1011 CFU/mL, which may be induced by its carrier strain, pET-28a. Strain 3458 poses the risk of increasing the number of pathogenic bacteria under prolonged exposure. When 500 mg L-1 chlorine-containing disinfectant or 250 mg L-1 chlorine dioxide disinfectant was added for 30 min, the sterilization rate exceeded 99.9 %. These findings suggest that existing wastewater disinfection methods can effectively sterilize strain 3458, ensuring its application value. The present study can serve a reference for the biosafety evaluation of the recombinant strain through exposure to the digestive tract and its feasibility for application in environmental pollution remediation.


Subject(s)
Containment of Biohazards , Disinfectants , Mice , Animals , Biodegradation, Environmental , Chromium/analysis , Disinfectants/toxicity , Risk Assessment
5.
J Hazard Mater ; 460: 132369, 2023 10 15.
Article in English | MEDLINE | ID: mdl-37634382

ABSTRACT

The combined pollution of heavy metals and microplastics is common in natural soil environments. Here, we collected 790 data sets from 39 studies to investigate the effects of microplastics on heavy metal bioavailability. The results showed that microplastics could increase the bioavailability of Cu, Pb, Cd, Fe, and Mn. The heavy metal bioavailability was positively correlated with microplastic size, soil sand concentration, and exposure time, but negatively correlated with soil pH and organic matter. The bioavailability of heavy metals can be promoted by microplastics of all shapes. Hydrolysable microplastics, which contain N, might have less influence. Furthermore, the size of microplastics and soil organic matter were positively correlated with the acid-soluble and reducible fractions of heavy metals, while the microplastic concentration, soil pH, and exposure time were positively correlated with the oxidizable fractions of heavy metals. The interaction detector results indicated that there was an interaction between microplastic characteristics, especially polymer types, and soil physicochemical indexes on the bioavailability of heavy metals. These findings suggested that long-term combined pollution of microplastics and heavy metals might increase heavy metal bioavailability in soils, thereby extending their migratory and hazardous range and bringing further risks to the environment and public health safety.


Subject(s)
Metals, Heavy , Soil , Microplastics , Plastics , Biological Availability
6.
Microorganisms ; 10(7)2022 Jul 17.
Article in English | MEDLINE | ID: mdl-35889160

ABSTRACT

Decabromodiphenyl ether (BDE-209), a polybrominated diphenyl ether (PBDE) homolog, seriously threatens human health. In this study, a Rhodococcus ruber strain with high BDE-209 degradation activity, named TAW-CT127, was isolated from Tong'an Bay, Xiamen. Under laboratory conditions, the strain's optimal growth temperature, pH, and salinity are 45 °C, 7.0, and 0-2.5%, respectively. Scanning electron microscopy (SEM) analysis shows that TAW-CT127 is damaged when grown in manual marine culture (MMC) medium with BDE-209 as the sole carbon source instead of eutrophic conditions. In the dark, under the conditions of 28 °C, 160 rpm, and 3 g/L (wet weight) TAW-CT127, the degradation rate of 50 mg/L BDE-209 is 81.07%. The intermediate metabolites are hexabromo-, octabromo-, and nonabromo-diphenyl ethers. Through whole-genome sequencing, multiple dehalogenases were found in the genome of TAW-CT127; these may be involved in the production of lower-brominated diphenyl ethers. Additionally, biphenyl-2,3-dioxygenase (BDO) in TAW-CT127 may catalyze the debromination reaction of BDE-209. Our research provides a new high-efficiency strain for bioremediation of BDE-209 pollution, and lays the foundation for the preliminary exploration of genes associated with BDE-209 degradation.

7.
Front Microbiol ; 13: 820657, 2022.
Article in English | MEDLINE | ID: mdl-35308358

ABSTRACT

Hexavalent chromium [Cr(VI)], a recognized heavy metal pollutant, has attracted much attention because of its negative impact on the ecological environment and human health. A chromium-resistant strain, Sporosarcina saromensis M52, was discovered, and the functional genes orf2987, orf3015, orf0415, and orf3237 were identified in the strain by genomics. With the advancement of DNA recombination and gene-splicing technology, genetic engineering technology was used to produce recombinant strains 2987, 3015, 0415, and 3237. The study revealed Cr(VI) tolerance in the order of M52 ≈ 2987 > 3015 ≈ 0415 > 3237 and reduction abilities in the order of M52 ≈ 2987 > 3015 > 0415 ≈ 3237. SEM-EDS, XRD, FT-IR and XPS were utilized to examine the surface structure of the recombinant strains and analyze the surface components and main functional groups. A comprehensive review of the recombinant strains' capacity to tolerate and reduce Cr(VI) revealed that orf2987 and orf0415 were the main functional genes in Sporosarcina saromensis M52, which may play a key role in removing Cr(VI) and protecting the strain, respectively. The optimum pH for recombinant strains 2987 and 0415 was 7.5-8.5, and the optimum temperature was 37°C. Cu2+ had the greatest promotional effect when Cr(VI) was removed by them, while SDS had an inhibitory effect. This research provided the foundation for further study into the mechanism of Cr(VI) reduction in Sporosarcina saromensis M52, as well as a theoretical basis for the development of effective engineered strains to repair Cr(VI) contamination.

8.
Ecotoxicol Environ Saf ; 225: 112767, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34507039

ABSTRACT

Serious hexavalent chromium [Cr(VI)] pollution has continuously threatened ecological security and public health. Microorganism-assisted remediation technology has strong potential in the treatment of environmental Cr(VI) pollution due to its advantages of high efficiency, low cost, and low secondary pollution. Sporosarcina saromensis M52, a strain with strong Cr(VI) removal ability, isolated from coastal intertidal zone was used in this study. Scanning electron microscopy coupled with energy dispersive X-ray analysis indicated M52 was relatively stable under Cr(VI) stress and trace amount of Cr deposited on the cell surface. X-ray photoelectron spectroscopy and X-ray diffraction analyses exhibited M52 could reduce Cr(VI) into Cr(III). Fourier transform infrared spectroscopy showed the bacterial surface was mainly consisted of polysaccharides, phosphate groups, carboxyl groups, amide II (NH/CN) groups, alkyl groups, and hydroxyl groups, while functional groups involving in Cr(VI) bio-reduction were not detected. According to these characterization analyses, the removal of Cr(VI) was primarily depended on bio-reduction, instead of bio-adsorption by M52. Genome analyses further indicated the probable mechanisms of bio-reduction, including the active efflux of Cr(VI) by chromate transporter ChrA, enzymatic redox reactions mediated by reductases, DNA-repaired proteases ability to minimize the ROS damage, and the formation of specific cell components to minimize the biofilm injuries caused by Cr(VI). These studies provided a theoretical basis which was useful for Cr(VI) remediation, especially in terms of increasing its effectiveness. THE MAIN FINDING OF THE WORK: M52 realized the bioremediation of Cr(VI) majorly through bio-reduction, including Cr(VI) efflux, chromate reduction, DNA repair, and the formation of specific cell components, instead of bio-adsorption.


Subject(s)
Genomics , Sporosarcina , Chromium , Sporosarcina/genetics
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