Effects and mechanisms of aquatic landscape plants on the removal of veterinary antibiotics from hydroponic solutions.

Four aquatic landscape plants and three veterinary antibiotics were selected to construct a hydroponic test system to analyze the tolerance, removal effect and mechanism of antibiotics. The results indicated that antibiotic concentrations from 0 to 100 µg·L-1 promoted plant heights and leaf chlorophyll contents, while antibiotics at concentrations > 100 µg·L-1 had inhibitory effects. The ability of different plants to remove antibiotics was Acorus calamus L. > Ceratophyllum demersum L. > Thalia dealbata Fraser > Nuphar pumila (Timm) DC. The plants with the best removal of norfloxacin, sulfadimethoxine and chlortetracycline were Ceratophyllum demersum L., Acorus calamus L. and Acorus calamus L. after 12 d of hydroponic cultivation using 100 µg·L-1 antibiotics, with removal rates of 66.6%, 63.0% and 63.2%, respectively. The accumulation of antibiotics in different plant tissues was root > stem > leaf and the accumulation increased with incubation time. The diversity of plant root biofilm microorganisms decreased with increasing treatment concentrations of antibiotics, while the abundance of dominant genera (Aeromonas, Bacillus, Lysinibacillus, Providencia, and Staphylococcus) showed an increasing trend. The findings imply that the antibiotic uptake by plants and the dynamics of the rhizosphere microbial community combine to promote antibiotic removal.

Different plants have different removal capacities for pollutants, and optimal plant selection is critical for antibiotic removal in phytoremediation and constructed wetland projects. Currently, although there are a small number of preliminary studies on the effect and mechanism of plant removal of antibiotics from wastewater, there is a lack of systematic understanding of the antibiotic removal capacity, uptake and accumulation characteristics, and possible coupling of microbial communities in the root zone of common aquatic landscape plants. In this study, common veterinary antibiotics (chlortetracycline, sulfadimethoxine, and norfloxacin) were selected as pollutants based on the use of veterinary medicines in farms, and common aquatic landscape plants (Acorus calamus L., Thalia dealbata Fraser, Ceratophyllum demersum L., and Nuphar pumila (Timm) DC.) were selected for hydroponic tests under different concentration treatments of antibiotics. We analyzed the tolerance, removal effect, uptake and accumulation characteristics of these plants to antibiotics in hydroponic solution and the evolutionary pattern of the microbial community in the root zone, in order to improve the understanding of the phytoremediation mechanism of antibiotics in aquatic environments. Meanwhile, this study searched for aquatic landscape plants with superior removal capacity for antibiotics, which was expected to provide a reference for phytoremediation and constructed wetland projects.

Measuring small displacements of an optical point source with digital holography.

The image of an optical point source is blurred due to light diffraction so that estimating small displacements of the point source with direct imaging demands elaborate processing on the observation data of a camera. Using quantum parameter estimation, we show that for the imaging systems with a real point spread function, any measurement basis constituted by a complete set of real-valued spatial-mode functions is optimal for estimating the displacement. For small displacements, we can concentrate the information about the value of displacement to the measurement of a few spatial modes, which can be selected in terms of the Fisher information distribution. We use digital holography with a phase-only spatial light modulator to implement two simple estimation strategies that are mainly based on the projection measurement of two spatial modes and the readout of a single pixel of a camera.

Quantum routings for single photons with different frequencies.

Controllable single-photon routing takes the central roles in optical quantum networks for quantum information processing. Given that most of the schemes previously proposed are specifically designed for the photons with selected frequencies, here we investigate how to implement the routings of single photons with different frequencies. We show that the routing capabilities of the photons with different frequencies are manipulatable by properly designing the configuration of the scatters such as the cavity with embedded atoms and the channel boundaries. This is particularly important to implement the bandwidth routings of photons in future.

Incorporating Heisenberg's Uncertainty Principle into Quantum Multiparameter Estimation.

The quantum multiparameter estimation is very different from the classical multiparameter estimation due to Heisenberg's uncertainty principle in quantum mechanics. When the optimal measurements for different parameters are incompatible, they cannot be jointly performed. We find a correspondence relationship between the inaccuracy of a measurement for estimating the unknown parameter with the measurement error in the context of measurement uncertainty relations. Taking this correspondence relationship as a bridge, we incorporate Heisenberg's uncertainty principle into quantum multiparameter estimation by giving a trade-off relation between the measurement inaccuracies for estimating different parameters. For pure quantum states, this trade-off relation is tight, so it can reveal the true quantum limits on individual estimation errors in such cases. We apply our approach to derive the trade-off between attainable errors of estimating the real and imaginary parts of a complex signal encoded in coherent states and obtain the joint measurements attaining the trade-off relation. We also show that our approach can be readily used to derive the trade-off between the errors of jointly estimating the phase shift and phase diffusion without explicitly parametrizing quantum measurements.

Distribution of Metal Resistance Genes in Estuarine Sediments and Associated Key Impact Factors.

Currently, little is known about the distribution of metal resistance genes (MRGs) in estuarine sediments. In this study, we used the high-throughput quantitative real-time polymerase chain reaction (HT-qPCR) to determine the distribution of MRGs in the sediments of an estuary system and the associated key impact factors. The relative abundance of the detected MRGs showed a decreasing trend from the river inlet toward the sea and a decrease from the middle area of the estuary to the near-shore areas on both sides; these decreases were higher in the summer than in the winter. In the estuary system during the summer, the abundance of Zn- and Cu-MRGs from the river inlet to the sea decreased by 99.5% and 93.6%, whereas those of Hg- and Cd-Zn-Co-MRGs increased by 51.5% and 16.7%, respectively. Moreover, the abundance of Zn- and Cu-MRGs in the winter decreased by 88.6% and 97.7%, respectively, whereas that of Cd-Bi-Zn-Pb-MRGs increased by 729.6%. Furthermore, the abundances of MRGs and mobile genetic elements (MGEs) were significantly positively correlated with the levels of antibiotic residues and heavy metals as well as with the particle size and total organic carbon content of the sediment; however, they were significantly negatively correlated with seawater salinity and the oxidation and reduction potential (Eh) and pH of the sediment. The abundance of MGEs was significantly positively correlated with the abundance of MRGs in the sediment. Our findings suggest that antibiotic residues facilitated the proliferation and propagation of MRGs by promoting MGEs in estuarine sediments.

One-sided device-independent quantum key distribution for two independent parties.

Remote distribution of secret keys is a challenging task in quantum cryptography. A significant step in this direction is the measurement-device independence quantum key distribution (MDI-QKD). For two remote (or independent) parties Alice and Bob who initially no share secret information, the MDI-QKD enables them to share a secret key by the measurement of an untrusted relay. Unfortunately, the MDI-QKD yields the assumption that the devices of both Alice and Bob have to be trusted. Here, we show that QKD between two independent parties can also be realized even if the device of either Alice or Bob is untrusted. We tackle the problem by resorting to the recently developed one-sided device-independent QKD protocol. We derive conditions on the extracted secret key to be unconditionally secure against arbitary attacks in the limit of asymptotic keys. In the presence of Gaussian states and measurements, we theoretically demonstrate our scheme is feasible, which could be an attractive candidate for long distance secret communication.

The mesopancreas and pancreatic head plexus: morphological, developmental, and clinical perspectives.

PURPOSE: Total mesopancreas excision has been found to be helpful for increasing no residual tumor resection rate and improving the prognosis of pancreatic cancer. This study analyzed the relationships among the mesopancreas and pancreatic head plexus from the morphological, developmental, and clinical perspectives. METHODS: Twenty-four cadavers were employed. The upper abdominal viscera were resected en-bloc with the hepatoduodenal ligament, abdominal aorta, and nerve plexuses, and the innervation of the pancreas was dissected. Ten additional cadavers were used for histological examination of the pancreatic head and neck, part of the duodenum, the superior mesenteric artery (SMA) and its surrounding tissues, and the related arteries and veins. RESULTS: As results, cross-sections of the SMA revealed 6-9 layers of membranous structures resembling the layers of an onion, and the nerve fibers of the superior mesenteric plexus ran between the layers. Loose areolar tissue, adipose tissue, and lymphatics existed between the SMA and the pancreatic head/uncinate process, along with abundant thin blood vessels and capillaries, but very few nerves were found approaching the pancreas. Several parallel layers of collagen fibers (so-called Treitz's fusion fascia) existed between the dorsal aspect of the pancreatic head and the aortocaval plane. CONCLUSION: The mesopancreas was continuous and connected with the para-aortic area. It may be better termed the mesopancreatoduodenum than the mesopancreas, as the duodenum-pancreas-SMA forms a complex morphological, developmental, functional, and pathological structure.

Response of microbial communities to pesticide residues in soil restored with Azolla imbricata.

Under conditions of Azolla imbricata restoration, the high-throughput sequencing technology was employed to determine change trends of microbial community structures in the soil that had undergone long-term application of pesticides. The relationship between the content of pesticide residues in the soil and the microbial community structure was analyzed. The results indicated that the microbial diversity was strongly negatively correlated with the contents of pesticide residues in the soil. At a suitable dosage of 5 kg fresh A. imbricata per square meter of soil area, the soil microbial diversity increased by 12.0%, and the contents of pesticide residues decreased by 26.8-72.1%. Sphingobacterium, Sphingopyxis, Thermincola, Sphingobium, Acaryochloris, Megasphaera, Ralstonia, Pseudobutyrivibrio, Desulfitobacterium, Nostoc, Oscillochloris, and Aciditerrimonas may play major roles in the degradation of pesticide residues. Thauera, Levilinea, Geothrix, Thiobacillus, Thioalkalispira, Desulfobulbus, Polycyclovorans, Fluviicola, Deferrisoma, Erysipelothrix, Desulfovibrio, Cytophaga, Vogesella, Zoogloea, Azovibrio, Halomonas, Paludibacter, Crocinitomix, Haliscomenobacter, Hirschia, Silanimonas, Alkalibacter, Woodsholea, Peredibacter, Leptolinea, Chitinivorax, Candidatus_Lumbricincola, Anaerovorax, Propionivibrio, Parasegetibacter, Byssovorax, Runella, Leptospira, and Nitrosomonas may be indicators to evaluate the contents of pesticide residues.

Metagenomic Insights into Effects of Chemical Pollutants on Microbial Community Composition and Function in Estuarine Sediments Receiving Polluted River Water.

Pyrosequencing and metagenomic profiling were used to assess the phylogenetic and functional characteristics of microbial communities residing in sediments collected from the estuaries of Rivers Oujiang (OS) and Jiaojiang (JS) in the western region of the East China Sea. Another sediment sample was obtained from near the shore far from estuaries, used for contrast (CS). Characterization of estuary sediment bacterial communities showed that toxic chemicals potentially reduced the natural variability in microbial communities, while they increased the microbial metabolic enzymes and pathways. Polycyclic aromatic hydrocarbons (PAHs) and nitrobenzene were negatively correlated with the bacterial community variation. The dominant class in the sediments was Gammaproteobacteria. According to Kyoto Encyclopedia of Genes and Genomes (KEGG) enzyme profiles, dominant enzymes were found in estuarine sediments, which increased greatly, such as 2-oxoglutarate synthase, acetolactate synthase, inorganic diphosphatase, and aconitate hydratase. In KEGG pathway profiles, most of the pathways were also dominated by specific metabolism in these sediments and showed a marked increase, for instance alanine, aspartate, and glutamate metabolism, carbon fixation pathways in prokaryotes, and aminoacyl-tRNA biosynthesis. The estuarine sediment bacterial diversity varied with the polluted river water inputs. In the estuary receiving river water from the more seriously polluted River Oujiang, the sediment bacterial community function was more severely affected.

Restoration using Azolla imbricata increases nitrogen functional bacterial groups and genes in soil.

Microbial groups are major factors that influence soil function. Currently, there is a lack of studies on microbial functional groups. Although soil microorganisms play an important role in the nitrogen cycle, systematic studies of the effects of environmental factors on microbial populations in relation to key metabolic processes in the nitrogen cycle are seldom reported. In this study, we conducted a systematic analysis of the changes in nitrogen functional groups in mandarin orange garden soil treated with Azolla imbricata. The structures of the major functional bacterial groups and the functional gene abundances involved in key processes of the soil nitrogen cycle were analyzed using high-throughput sequencing (HTS) and quantitative real-time PCR, respectively. The results indicated that returning A. imbricata had an important influence on the composition of soil nitrogen functional bacterial communities. Treatment with A. imbricata increased the diversity of the nitrogen functional bacteria. The abundances of nitrogen functional genes were significantly higher in the treated soil compared with the control soil. Both the diversity of the major nitrogen functional bacteria (nifH bacteria, nirK bacteria, and narG bacteria) and the abundances of nitrogen functional genes in the soil showed significant positive correlations with the soil pH, the organic carbon content, available nitrogen, available phosphorus, and NH4+-N and NO3--N contents. Treatment with 12.5 kg fresh A. imbricata per mandarin orange tree was effective to improve the quality of the mandarin orange garden soil. This study analyzed the mechanism of the changes in functional bacterial groups and genes involved in key metabolic processes of the nitrogen cycle in soil treated by A. imbricata.

Temporal-spatial variation of bacterial diversity in estuary sediments in the south of Zhejiang Province, China.

The winter and summer microbial community structure in sediment samples obtained from the estuaries of the wastewater-polluted River Ou (DO and XO), River Feiyun (DF and XF), and River Ao (DA and XA) in the south of Zhejiang Province in China was determined using 454 pyrosequencing. Sediment samples (DD and XD) were also correspondingly collected near the shore far from the estuaries for comparison. For the above sediments, 294,870 effective sequences were obtained to do the bacterial diversity and abundance determination. In total, 1924, 1517, 2071, 1956, 1995, 1800, 2261, and 2097 operational taxonomic units were obtained at 3 % distance cutoff in the DO, XO, DF, XF, DA, XA, DD, and XD sediments, respectively. Bacterial phylotype richness in DD was higher than the other sediments, and XO had the least richness. The most dominant class in the DA, DD, DF, DO, and XA sediments is Gammaproteobacteria. Deltaproteobacteria is the most dominant one in XD, XO, and XF. Circa 14.4 % sequences in XD were found to be affiliated with the Flavobacteriales order. Characterization of the estuarine sediment bacterial communities indicated that chemical pollution has the potential to decrease the natural variability that exists among estuary ecosystems. However, chemical pollutants did not cause clear bio-homogenization in these estuaries.

Time Course of Carbendazim Stimulation on Pathogenicity of Sclerotinia sclerotiorum Indicates a Direct Stimulation Mechanism.

Previous studies have demonstrated that subtoxic doses of carbendazim have a stimulatory effect on pathogenicity of Sclerotinia sclerotiorum on rapeseed plants. The present study focused on the time-course profile of the stimulatory effect and its relevance to stimulation mechanisms. At 12 h postinoculation (HPI), initial necrotic lesions were visible only for rapeseed leaves treated with carbendazim at 0.2 and 1 µg/ml, whereas no disease symptoms were observed for the nontreated control. At 18 HPI, carbendazim stimulation on pathogenicity was more obvious than at 12 HPI. Study with scanning electron microscopy demonstrated that no discernable differences in the development of disease symptoms could be detected at 8 HPI. However, at 12 HPI, necrotic symptoms of the epidermal cells were apparent only for leaves sprayed with carbendazim. These results indicated that stimulations on pathogenicity occurred in the first 12 h, implying that direct stimulation rather than overcompensation to the disruption of homeostasis was likely to be the underlying mechanism for pathogenicity stimulation. Greenhouse experiments showed that spraying carbendazim at 400 µg/ml on potted rapeseed plants had statistically significant (P < 0.05) stimulations on pathogenicity for inoculations at 1, 3, 5, and 7 days after application (DAA). The stimulation action eventually disappeared for inoculations at 14 DAA. Mycelia grown on potato dextrose agar (PDA) supplemented with carbendazim at 400 µg/ml were more pathogenic than the nontreated control. However, after additional growth of the mycelia on fungicide-free PDA for 2 days, the stimulatory effect disappeared completely, indicating that carbendazim was indispensable for pathogenicity stimulations. Studies on biochemical mechanisms indicated that cell-wall-degrading enzymes such as cellulase, pectinase, and polygalacturonase were not involved in pathogenicity stimulations. These results will advance our understanding of the nature and mechanisms of fungicide stimulation on fungal pathogenicity and, thus, are valuable for judicious applications of fungicides.

Pathogenicity Stimulation of Sclerotinia sclerotiorum by Subtoxic Doses of Carbendazim.

Sclerotinia sclerotiorum is a devastating ascomycete fungus capable of infecting more than 400 species of plants worldwide. Carbendazim has been a principal fungicide for control of this pathogen and high levels of carbendazim resistance have been reported in eastern China. In this study, stimulatory effect of subtoxic doses of carbendazim on pathogenicity of S. sclerotiorum was investigated. All seven field resistant isolates with EC50 values greater than 1,000 µg/ml exhibited stimulated pathogenicity toward detached leaves of rapeseed at subtoxic concentrations of carbendazim. Detailed studies on pathogenicity of two resistant isolates AH-17 and LJ-86 toward potted rapeseed plants and detached leaves demonstrated that carbendazim at 0.2 to 5 µg/ml could consistently stimulate significantly higher (P < 0.05) pathogenicity than the control. On potted rapeseed plants, the percent stimulations on pathogenicity ranged from 18.8 to 22.0% for isolate AH-17 and from 15.1 to 23.2% for isolate LJ-86. On detached leaves of rapeseed, the percent stimulations ranged from 18.7 to 31.29% for isolate AH-17 and from 16.7 to 24.3% for isolate LJ-86. Studies on stimulation mechanism indicated that secretion of oxalic acid and tolerance to oxidative stresses H2O2 and paraquat after exposed to subtoxic doses of carbendazim did not change significantly. These results have profound implications for judicious application of fungicides and sustainable management of fungicide resistance.

Characterization of bacterial communities in sediments receiving various wastewater effluents with high-throughput sequencing analysis.

454 Pyrosequencing was applied to examine bacterial communities in sediment samples collected from a river receiving effluent discharge from rural domestic sewage (RDS) and various factories, including a tannery (TNS), clothing plant (CTS), and button factory (BTS), respectively. For each sample, 4,510 effective sequences were selected and utilized to do the bacterial diversity and abundance analysis, respectively. In total, 1,288, 2,036, 1,800, and 2,150 operational taxonomic units were obtained at 3% distance cutoff in TNS, CTS, BTS, and RDS, respectively. Bacterial phylotype richness in RDS was higher than the other samples, and TNS had the least richness. The most predominant class in the TNS, CTS, and BTS samples is Betaproteobacteria. Cyanobacteria (no_rank) is the most predominant one in the RDS sample. Circa 31% sequences in TNS were affiliated with the Rhodocyclales order. In the four samples, Aeromonas, Arcobacter, Clostridium, Legionella, Leptospira, Mycobacterium, Pseudomonas, and Treponema genera containing pathogenic bacteria were detected. Characterization of bacterial communities in sediments from various downstream branches indicated that distinct wastewater effluents have similar potential to reduce the natural variability in river ecosystems and contribute to the river biotic homogenization.

Effects of farmhouse hotel and paper mill effluents on bacterial community structures in sediment and surface water of Nanxi River, China.

The pyrosequencing technique was used to evaluate bacterial community structures in sediment and surface water samples taken from Nanxi River receiving effluents from a paper mill and a farmhouse hotel, respectively. For each sample, 4,610 effective bacterial sequences were selected and used to do the analysis of diversity and abundance, respectively. Bacterial phylotype richness in the sediment sample without effluent input was higher than the other samples, and the surface water sample with addition of effluent from the paper mill contained the least richness. Effluents from both the paper mill and farmhouse hotel have a potential to reduce the bacterial diversity and abundance in the sediment and surface water, especially it is more significant in the sediment. The effect of the paper mill effluent on the sediment and surface water bacterial communities was more serious than that of the farmhouse hotel effluent. Characterization of microbial community structures in the sediment and surface water from two tributaries of the downstream river indicated that various effluents from the paper mill and farmhouse hotel have the similar potential to decrease the natural variability in riverine microbial ecosystems.

Diversity, abundance, and spatial distribution of riverine microbial communities response to effluents from swine farm versus farmhouse restaurant.

The 454 pyrosequencing technique was applied to evaluate microbial community composition in sediment and water samples collected from the river receiving effluents from a swine farm and a farmhouse restaurant, respectively. For each sample, 4,600 effective sequences were selected and used to do the bacterial diversity and abundance analysis, respectively. Bacterial phylotype richness in the river sediment sample without effluent input was higher than the other samples, and the river water sample with addition of effluent from the swine farm had the least richness. Effluents from both the swine farm and the farmhouse restaurant have the potential to decrease the bacterial diversity and abundance in the river sediment and water, especially it is more significant in the river sediment. Effect of effluent from the swine farm on riverine bacterial communities was more significant than that from the farmhouse restaurant. Characterization of bacterial community composition in sediments from two tributaries of the downstream river showed that various effluents from the swine farm and the farmhouse restaurant have the similar potential to reduce the natural variability in riverine ecosystems, and contribute to the biotic homogenization in the river sediment.

Bacterial communities in manures of piglets and adult pigs bred with different feeds revealed by 16S rDNA 454 pyrosequencing.

Pyrosequencing-based analysis was used to characterize and compare bacterial communities in manure samples of piglets (GSPM) and adult pigs (GBPM) bred with green feeds without additives, and piglets (ASPM) and adult pigs (ABPM) bred with synthetic feeds containing additives. For each sample, 5,010 effective sequences were selected and utilized to do the bacterial composition analysis, respectively. In total, 1,489, 1,327, 941, and 883 operational taxonomic units were obtained at 5 % distance cutoff in GBPM, GSPM, ABPM, and ASPM, respectively. Bacterial phylotype richness in GBPM was higher than the other samples, and ASPM had the least richness. The most dominant class in the four samples is Bacteroidia. Approximately 41 % sequences in GBPM were affiliated with the Clostridiales order. Campylobacter, Clostridium and Streptococcus genera containing pathogenic bacteria were detected in the four samples. Bacterial diversity and abundance in swine manures varied with piglets, adult pigs, and feeds. In the four samples, higher bacterial diversity but less potentially pathogenic bacterial genera in manures of adult pigs bred with green feeds were found, which indicated that those manures were more suitable for resource utilization. This study also provides evidence for the reasonableness of pig farming with green feeds.

Changes in visual performance after implantation of different intraocular lenses.

AIM: To evaluate the trending visual performance of different intraocular lenses (IOLs) over time after implantation. METHODS: Ninety-one patients received cataract surgery with implantations of monofocal (Mon) IOLs, segmental refractive (SegRef) IOLs, diffractive (Dif) IOLs, and extended-depth-of-focus (EDoF) IOLs were included. The aberrations and optical quality collected with iTrace and OQAS within postoperative 6mo were followed and compared. RESULTS: Most of the visual parameters improved over the postoperative 6mo. The postoperative visual acuity (POVA) of the Mon IOL, SegRef IOL, and EDoF IOL groups achieved relative stability in earlier states compared with the Dif IOL group. Nevertheless, the overall visual performance of the 3 IOLs continued to upturn in small extents within the postoperative 6mo. The optical quality initially improved in the EDoF IOL group, then in the Mon IOL, SegRef IOL, and Dif IOL groups. POVA and objective visual performance of the Mon IOL and EDoF IOL groups, as well as POVA and visual quality of the Dif IOL group, improved in the postoperative 1mo and stabilized. Within the postoperative 6mo, gradual improvements were observed in the visual acuity and objective visual performance of the SegRef IOL group, as well as in the postoperative optical quality of the Dif IOL group. CONCLUSION: The visual performance is different among eyes implanted with different IOLs. The findings of the current study provide a potential reference for ophthalmologists to choose suitable IOLs for cataract patients in a personalized solution.

Response process and adaptation mechanism of estuarine benthic microbiota to polyvinyl chloride microplastics with and without phthalates.

This study aimed to explore the response mechanisms of the microbiota in estuarine sediments amended with polyvinyl chloride (PVC) microplastics (MPs) with and without phthalates (PAEs) through a 60-day microcosm experiment. The results indicated that addition of MPs increased the porosity of the sediment. However, the sediment porosity decreased with the length of the amendment period. Following amendment with MPs containing PAEs, the sediment PAE content increased over time. The addition of MPs without PAEs increased the relative abundance of the dominant phyla of bacteria (Actinobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Gemmatimonadetes, and Planctomycetes) and eukaryotes (Ascomycota, Bacillariophyta, Chordata, and Streptophyta), whereas the relative abundance decreased over time following the addition of MPs containing PAEs. The PAEs released from MPs had greater effects on these phyla than the MPs themselves. The dominant bacteria were more sensitive to MPs than the dominant eukaryotes. After a 60-day amendment with MPs containing PAEs, the bacterial and eukaryotic species numbers were lower by 5.4% and 3.4%, respectively, the relative abundance of certain genes involved in metabolism was lower, and the relative abundance of stress-related genes was higher. These findings provide insight into the microbial response and adaptation mechanisms in estuarine environments polluted with MPs.

Varying characteristics and driving mechanisms of antibiotic resistance genes in farmland soil amended with high-density polyethylene microplastics.

The differential effects of microplastics and phthalates released from microplastics on antibiotic resistance genes in soil remain unknown. This study aims to analyze the varying characteristics and driving mechanisms of antibiotic resistance genes in soils amended with high-density polyethylene microplastics (with and without phthalates) through a 60-day microcosm experiment. The results indicate that the amended high-density polyethylene microplastics (containing phthalates) enhanced the abundance of antibiotic resistance genes in the soil, a phenomenon that markedly increased with the amendment period. Nevertheless, the addition of high-density polyethylene microplastics (without phthalates) mitigated the abundance of antibiotic resistance genes, which was less significant with increasing amendment period. Furthermore, addition of high-density polyethylene microplastics altered the soil properties, especially porosity. The phthalates released from high-density polyethylene microplastics and the changes in the soil properties transformed soil bacterial communities, resulting in increased abundance of bacterial hosts harboring antibiotic resistance genes (Calditrichaeota, Candidate division CPR1, Candidatus Delongbacteria, Candidatus Kapabacteria, Candidatus Spechtbacteria, Candidatus Wildermuthbacteria, and Ignavibacteriae), thereby enhancing the abundance of antibiotic resistance genes. These findings suggest that compared to microplastics, the phthalates released from microplastics considerably affect the antibiotic resistance genes in soils, thereby promoting the propagation of antibiotic resistance genes in agricultural environments.