scispace - formally typeset
Journal ArticleDOI: 10.1016/J.JHAZMAT.2020.124206

Addition of nanoparticles increases the abundance of mobile genetic elements and changes microbial community in the sludge anaerobic digestion system.

05 Mar 2021-Journal of Hazardous Materials (Elsevier)-Vol. 405, pp 124206-124206
Abstract: This study explored the fate of mobile genetic elements (MGEs) in anaerobic digestion (AD) system with four nanoparticles (NPs) added, including carbon NPs, Al2O3 NPs, ZnO NPs, and CuO NPs. 16S rRNA amplicon sequencing and quantitative PCR to investigate the microbial community, MGEs abundance and the potential host in the AD process. The results of high-throughput sequencing showed that ZnO NPs and CuO NPs significantly reduced the microbial diversity and significantly changed the microbial community structure. Simultaneously, the absolute abundance of MGEs increased by 145.01%, 159.67%, 354.70%, and 132.80% on the carbon NPs, Al2O3 NPs, ZnO NPs, and CuO NPs. The enrichment rate of tnpA-03 in ZnO NPs group was the highest, which could reach up to 2854.80%. Co-occurrence analysis revealed that Proteobacteria harbored the vast majority of MGEs followed by Firmicutes. Redundancy analysis and variation partitioning analysis showed that metabolites were the main factors that shifted the succession of bacterial communities. Moreover, there were significant positive correlations between metabolites and part MGEs (such as tnpA-01, tnpA-02, tnpA-03, tnpA-04, tnpA-05, tnpA-07 and ISCR1). This study provides a new perspective that NPs increase the risk of antibiotic resistance through MGEs during AD process.

... read more


7 results found

Journal ArticleDOI: 10.1016/J.JHAZMAT.2021.126602
Guanqun Feng1, Haining Huang1, Yinguang Chen1Institutions (1)
Abstract: The emergence and spread of antibiotic resistance genes (ARGs) have become major concerns for both public health and environmental ecosystems. Emerging pollutants (EPs) that accumulate in environmental compartments also pose a potential risk for the enrichment of ARGs in indigenous microorganisms. This paper presents a comprehensive review of the effects and intrinsic mechanisms of EPs, including microplastics, engineered nanomaterials, disinfection byproducts, pharmaceuticals, and personal care products, on the occurrence and dissemination of ARGs. State-of-the-art methods for identifying culture-independent ARG-host interactions and monitoring horizontal gene transfer (HGT) processes in real-time are first reviewed. The contributions of EPs to the abundance and diversity of ARGs are then summarized. Finally, we discussed the underlying mechanisms related to the regulation of HGT, increased mutagenesis, and the evolution of microbial communities. Further details of three HGT (i.e., conjugation, transformation, and transduction) frequency patterns in response to various EPs are also examined. This review contemplates and reassesses the risks of ARG evolution posed by the manufacture and application of EPs.

... read more

6 Citations

Journal ArticleDOI: 10.1016/J.SCITOTENV.2021.145969
Abstract: The effects of adding zero-valent iron nanoparticles (nZVI) on the physicochemical, biological and biochemical responses of a semi-continuous anaerobic digestion of sewage sludge have been assessed. Two sets of consecutive experiments of 103 and 116 days, respectively, were carried out in triplicate. nZVI were magnetically retained in the reactors, and the effect of punctual doses (from 0.27 to 4.33 g L−1) over time was studied. Among the different parameters monitored, only methane content in the biogas was significantly higher when nZVI was added. However, this effect was progressively lost after the addition, and in 5–7 days, the methane content returned to initial values. The increase in the oxidation state of nanoparticles seems to be related to the loss of effect over time. Higher dose (4.33 g L−1) sustained positive effects for a longer time along with higher methane content, but this fact seems to be related to microbiome acclimation. Changes in microbial community structure could also play a role in the mechanisms involved in methane enhancement. In this sense, the microbial consortium analysis reported a shift in the balance among acetogenic eubacterial communities, and a marked increase in the relative abundance of members assigned to Methanothrix genus, recognized as acetoclastic species showing high affinity for acetate, which explain the rise in methane content in the biogas. This research demonstrates that biogas methane enrichment in semicontinuous anaerobic digesters can be achieved by using nZVI nanoparticles, thus increasing energy production or reducing costs of a later biogas upgrading process.

... read more

Topics: Anaerobic digestion (58%), Biogas (57%), Sludge (53%) ... show more

4 Citations

Journal ArticleDOI: 10.1016/J.CEJ.2021.131407
Xuran Liu1, Qizi Fu2, Zongyao Liu, Tianjing Zeng  +5 moreInstitutions (3)
Abstract: The residual Polyacrylamide (PAM) in sewage sludge might cause severe disturbance in anaerobic digestion, and appropriate solutions to alleviate such situation are urgently required. In present study, alkaline pre-fermentation was proposed for PAM-flocculated sewage sludge (PFS) pretreatment, by which both PFS methane production and PAM degradation were remarkably enhanced. Under the optimal alkaline pre-fermentation condition (pH 10 for 12 d), the biochemical methane potential of PFS (12 g PAM/kg TS) increased from 107.2 to 246.6 mL/g VS, the hydrolysis rate increased from 0.109 to 0.197 d−1, and the degradation efficiency of PAM increased from 30.6% to 80.1%. Mechanism analysis indicated that the alkaline pre-fermentation broke the large “PAM-sludge” floccules, decreased the molecular weight of PAM, which alleviated the disturbance situation of PAM-present digester and made PAM more available for microbes to be biodegraded. Moreover, PFS hydrolysis and acidification were simultaneously accelerated by alkaline pre-fermentation, thereby providing more bioavailable carbon substrates for subsequent methane producing and PAM co-metabolism. Microbial community analysis demonstrated syntrophic bacteria such as Petrimonas and Sedimentibacter, which had ability to degrade an extensive range of various types of organics including carbohydrates and PAM, were enriched in alkaline pre-fermenter, and the acetotrophic methanogen Methanosaeta, were elevated in anaerobic digester. This work provides an effective microbial based strategy to improve the efficiency of anaerobic digestion of PFS.

... read more

Topics: Anaerobic digestion (56%), Sludge (53%), Methanogen (52%)

1 Citations

Journal ArticleDOI: 10.1016/J.CHEMOSPHERE.2021.131744
Xiyan Ji1, Yunchao Tang1, Jing Ye1, Shichao Wu1  +3 moreInstitutions (1)
01 Jan 2022-Chemosphere
Abstract: The presence of Microcystis aeruginosa (M. aeruginosa) can affect the transference of antibiotic resistance genes (ARGs), and the presence of carbon-based copper nanocomposites (CCN) can affect the growth of M. aeruginosa. However, the effect of CCN on M. aeruginosa and ARGs is not fully understood. In this study, metagenomic sequencing was employed to analyze the movability of ARGs, their potential transfer, and possible hosts in photobioreactor treating urban water. The results uggested that 20 mg/L of CCN changed the composition and abundance of microorganisms in urban water, significantly promoted the flocculation of M aeruginosa, and decreased the composing proportion of Cyanophyta sp. and M aeruginosa. The results indicated that 20 mg/L of CCN significantly decreased the absolute abundance and ARGs proportions which mediated by plasmids (32.7 %). Furthermore, the lower co-occurrence probability of ARGs and mobile genetic elements (MGEs) suggested that 20 mg/L of CCN weakened the movability potential of ARGs mediated by MGEs such as plasmids. Among the 452 metagenome-assembled genomes (MAGs), 95 MAGs belonging to 41 bacterial categories were identified as possible ARG hosts. These results will provide insights into the control of harmful cyanobacteria and the management of ARGs in urban water.

... read more

Topics: Microcystis aeruginosa (52%)

Journal ArticleDOI: 10.1016/J.SCITOTENV.2021.150822
Jingyang Luo1, Xiaoshi Cheng1, Yinglong Su2, Le Zhang1  +6 moreInstitutions (3)
Abstract: Waste activated sludge (WAS) is an important reservoir of antibiotic resistance genes (ARGs). However, the interactive effects of co-existed substances in WAS on ARGs fates have yet to be disclosed. This study demonstrated the type-dependent effects of surfactants (potentially effective chemicals for WAS disposal) on the reduction of ARGs during WAS fermentation, which followed the order of linear alkylbenzene sulphonates (LAS) > alkyl polyglucoside (APG) > hexadecyl trimethyl ammonium bromide (HTAB). Interestingly, the ratio of ARGs affiliated to efflux pump showed an upward trend in the surfactant-treated reactor. Mechanistic investigations revealed that the extracellular polymeric substances (EPS) destruction induced by surfactants increased the permeability of bacterial cells and caused the ARGs being released and susceptible for subsequent elimination. Besides, the surfactants significantly altered the microbial community, resulting in the ARGs reduction via changing the potential hosts. Also, the metabolic pathways participated in the dissemination of ARGs were remarkably down-regulated, thereby resulting in the reduction of ARGs abundances. This work broadened the understanding of ARGs fates during WAS fermentation and provided insights on the interactive functions of exogenous chemicals in multiple matrics.

... read more


57 results found

Open accessJournal ArticleDOI: 10.1021/NN800511K
Tian Xia1, Michael Kovochich, Monty Liong1, Lutz Mädler1  +6 moreInstitutions (4)
01 Oct 2008-ACS Nano
Abstract: Nanomaterials (NM) exhibit novel physicochemical properties that determine their interaction with biological substrates and processes. Three metal oxide nanoparticles that are currently being produced in high tonnage, TiO2, ZnO, and CeO2, were synthesized by flame spray pyrolysis process and compared in a mechanistic study to elucidate the physicochemical characteristics that determine cellular uptake, subcellular localization, and toxic effects based on a test paradigm that was originally developed for oxidative stress and cytotoxicity in RAW 264.7 and BEAS-2B cell lines. ZnO induced toxicity in both cells, leading to the generation of reactive oxygen species (ROS), oxidant injury, excitation of inflammation, and cell death. Using ICP-MS and fluorescent-labeled ZnO, it is found that ZnO dissolution could happen in culture medium and endosomes. Nondissolved ZnO nanoparticles enter caveolae in BEAS-2B but enter lysosomes in RAW 264.7 cells in which smaller particle remnants dissolve. In contrast, fluoresce...

... read more

Topics: Nanotoxicology (57%), Cerium oxide (50%)

1,993 Citations

Open accessJournal ArticleDOI: 10.1016/J.SCITOTENV.2013.01.032
Abstract: Urban wastewater treatment plants (UWTPs) are among the main sources of antibiotics' release into the environment. The occurrence of antibiotics may promote the selection of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB), which shade health risks to humans and animals. In this paper the fate of ARB and ARGs in UWTPs, focusing on different processes/technologies (i.e., biological processes, advanced treatment technologies and disinfection), was critically reviewed. The mechanisms by which biological processes influence the development/selection of ARB and ARGs transfer are still poorly understood. Advanced treatment technologies and disinfection process are regarded as a major tool to control the spread of ARB into the environment. In spite of intense efforts made over the last years to bring solutions to control antibiotic resistance spread in the environment, there are still important gaps to fill in. In particular, it is important to: (i) improve risk assessment studies in order to allow accurate estimates about the maximal abundance of ARB in UWTPs effluents that would not pose risks for human and environmental health; (ii) understand the factors and mechanisms that drive antibiotic resistance maintenance and selection in wastewater habitats. The final objective is to implement wastewater treatment technologies capable of assuring the production of UWTPs effluents with an acceptable level of ARB.

... read more

1,417 Citations

Journal ArticleDOI: 10.1146/ANNUREV.MICRO.57.030502.091014
Abstract: When free-living bacteria colonize biotic or abiotic surfaces, the resultant changes in physiology and morphology have important consequences on their growth, development, and survival. Surface motility, biofilm formation, fruiting body development, and host invasion are some of the manifestations of functional responses to surface colonization. Bacteria may sense the growth surface either directly through physical contact or indirectly by sensing the proximity of fellow bacteria. Extracellular signals that elicit new gene expression include autoinducers, amino acids, peptides, proteins, and carbohydrates. This review focuses mainly on surface motility and makes comparisons to features shared by other surface phenomenon.

... read more

Topics: Autoinducer (57%), Swarming motility (52%), Biofilm (51%)

838 Citations

Journal ArticleDOI: 10.1002/ADFM.200801081
Guy Applerot1, Anat Lipovsky1, Rachel Dror2, Nina Perkas1  +3 moreInstitutions (2)
Abstract: An innovative study aimed at understanding the influence of the particle size of ZnO (from the microscale down to the nanoscale) on its antibacterial effect is reported herein. The antibacterial activity of ZnO has been found to be due to a reaction of the ZnO surface with water. Electron-spin resonance measurements reveal that aqueous suspensions of small nanoparticles of ZnO produce increased levels of reactive oxygen species, namely hydroxyl radicals. Interestingly, a remarkable enhancement of the oxidative stress, beyond the level yielded by the ZnO itself, is detected following the antibacterial treatment. Likewise, an exposure of bacteria to the small ZnO nanoparticles results in an increased cellular internalization of the nanoparticles and bacterial cell damage. An examination of the antibacterial effect is performed on two bacterial species: Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive). The nanocrystalline particles of ZnO are synthesized using ultrasonic irradiation, and the particle sizes are controlled using different solvents during the sonication process. Taken as a whole, it is apparent that the unique properties (i.e., small size and corresponding large specific surface area) of small nanometer-scale ZnO particles impose several effects that govern its antibacterial action. These effects are size dependent and do not exist in the range of microscale particles.

... read more

Topics: Antibacterial activity (52%), Nanoparticle (52%), Sonication (50%)

740 Citations

Open accessJournal ArticleDOI: 10.1093/NAR/GKX295
Achal Dhariwal1, Jasmine Chong1, Salam Habib1, Irah L. King1  +2 moreInstitutions (1)
Abstract: The widespread application of next-generation sequencing technologies has revolutionized microbiome research by enabling high-throughput profiling of the genetic contents of microbial communities. How to analyze the resulting large complex datasets remains a key challenge in current microbiome studies. Over the past decade, powerful computational pipelines and robust protocols have been established to enable efficient raw data processing and annotation. The focus has shifted toward downstream statistical analysis and functional interpretation. Here, we introduce MicrobiomeAnalyst, a user-friendly tool that integrates recent progress in statistics and visualization techniques, coupled with novel knowledge bases, to enable comprehensive analysis of common data outputs produced from microbiome studies. MicrobiomeAnalyst contains four modules - the Marker Data Profiling module offers various options for community profiling, comparative analysis and functional prediction based on 16S rRNA marker gene data; the Shotgun Data Profiling module supports exploratory data analysis, functional profiling and metabolic network visualization of shotgun metagenomics or metatranscriptomics data; the Taxon Set Enrichment Analysis module helps interpret taxonomic signatures via enrichment analysis against >300 taxon sets manually curated from literature and public databases; finally, the Projection with Public Data module allows users to visually explore their data with a public reference data for pattern discovery and biological insights. MicrobiomeAnalyst is freely available at

... read more

Topics: Data profiling (64%), Exploratory data analysis (54%), Profiling (information science) (51%) ... show more

660 Citations