Many reports have documented that the presence of SARS-CoV-2 RNA in the influents of municipal wastewater treatment plants (WWTP) correlates with the actual epidemic situation in a given city. However, few data have been reported thus far on measurements upstream of WWTPs, i.e. throughout the sewer network. In this study, the monitoring of the presence of SARS-CoV-2 RNA in Prague wastewater was carried out at selected locations of the Prague sewer network from August 2020 through May 2021. Various locations such as residential areas of various sizes, hospitals, city center areas, student dormitories, transportation hubs (airport, bus terminal), and commercial areas were monitored together with four of the main Prague sewers. The presence of SARS-CoV-2 RNA was determined by reverse transcription - multiplex quantitative polymerase chain reaction (RT-mqPCR) after the precipitation of nucleic acids with PEG 8,000 and RNA isolation with TRIzolTM Reagent. The number of copies of the gene encoding SARS-CoV-2 nucleocapsid (N1) per liter of wastewater was compared with the number of officially registered COVID-19 cases in Prague. Although the data obtained by sampling wastewater from the major Prague sewers were more consistent than those obtained from the small sewers, the correlation between wastewater-based and clinical-testing data was also good for the residential areas with more than 7,000 registered inhabitants. It was shown that monitoring SARS-CoV-2 RNA in wastewater sampled from small sewers could identify isolated occurrences of COVID-19-positive cases in local neighborhoods. This can be very valuable while tracking COVID-19 hotspots within large cities.
- MeSH
- čištění vody * MeSH
- COVID-19 * epidemiologie MeSH
- lidé MeSH
- odpadní voda MeSH
- RNA virová MeSH
- SARS-CoV-2 MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Diphyllin is a natural arylnaphtalide lignan extracted from tropical plants of particular importance in traditional Chinese medicine. This compound has been described as a potent inhibitor of vacuolar (H+)ATPases and hence of the endosomal acidification process that is required by numerous enveloped viruses to trigger their respective viral infection cascades after entering host cells by receptor-mediated endocytosis. Accordingly, we report here a revised, updated, and improved synthesis of diphyllin, and demonstrate its antiviral activities against a panel of enveloped viruses from Flaviviridae, Phenuiviridae, Rhabdoviridae, and Herpesviridae families. Diphyllin is not cytotoxic for Vero and BHK-21 cells up to 100 μM and exerts a sub-micromolar or low-micromolar antiviral activity against tick-borne encephalitis virus, West Nile virus, Zika virus, Rift Valley fever virus, rabies virus, and herpes-simplex virus type 1. Our study shows that diphyllin is a broad-spectrum host cell-targeting antiviral agent that blocks the replication of multiple phylogenetically unrelated enveloped RNA and DNA viruses. In support of this, we also demonstrate that diphyllin is more than just a vacuolar (H+)ATPase inhibitor but may employ other antiviral mechanisms of action to inhibit the replication cycles of those viruses that do not enter host cells by endocytosis followed by low pH-dependent membrane fusion.
- MeSH
- antigeny virové metabolismus MeSH
- antivirové látky chemická syntéza farmakologie MeSH
- buněčné linie MeSH
- glukosidy farmakologie MeSH
- lignany chemická syntéza farmakologie MeSH
- replikace viru účinky léků MeSH
- vakuolární protonové ATPasy antagonisté a inhibitory MeSH
- viabilita buněk účinky léků MeSH
- viry klasifikace účinky léků metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Sufficient mixing is crucial for the proper performance of anaerobic digestion (AD), creating a homogeneous distribution of soluble substrates, biomass, pH, and temperature. The opaqueness of the sludge and mode of operation make it challenging to study AD mixing experimentally. Therefore, hydrodynamics modelling employing computational fluid dynamics (CFD) is often used to investigate this mixing. However, CFD models mostly do not include biochemical reactions and, hence, ignore the effect of diffusion-induced transport on AD heterogeneity. The novelty of this work is the partial integration of Anaerobic Digestion Model no. 1 (ADM1) into the CFD model. The aim is to better understand the effect of advection-diffusion transport on the homogenization of soluble substrates and biomass. Furthermore, AD homogeneity analysis in terms of concentration distribution is proposed rather than the traditional velocity distributions. The computed results indicate that including diffusion-induced transport affects the homogeneity of AD.
- MeSH
- anaerobióza MeSH
- bioreaktory MeSH
- difuze MeSH
- hydrodynamika * MeSH
- odpadní vody MeSH
- teoretické modely * MeSH
- Publikační typ
- časopisecké články MeSH
One of the major obstacles that limits the use of magnetic nanoparticles in biomedical applications is their potential toxicity. In the present study, we evaluated the cytotoxic effects of thiol-functionalized silica-coated iron oxide (Fe3O4@SiO2-SH) nanoparticles using human lung epithelial cells A549. We investigated the effect of Fe3O4@SiO2-SH nanoparticles on the cell viability, proliferation, cell cycle distribution, adhesion, apoptosis, and the orientation of the cytoskeletal networks, as well as on expression of proteins involved in cell death, cell survival, and cell adhesion. We demonstrated that exposure of A549 cells to Fe3O4@SiO2-SH nanoparticles resulted in severe disruption of the actin microfilaments and microtubule cytoskeleton and reduced the size of focal adhesions. Furthermore, cell adhesion was significantly affected as well as the phosphorylation of focal adhesion kinase (FAK), extracellular-signal-regulated kinase (ERK), and p38. Our findings highlight the need for in-depth cytotoxic evaluation of nanoparticles supporting their safer use, especially in biomedical applications.
- MeSH
- buněčná adheze účinky léků MeSH
- buňky A549 MeSH
- cytoskelet účinky léků MeSH
- lidé MeSH
- magnetické nanočástice oxidů železa chemie toxicita MeSH
- oxid křemičitý chemie MeSH
- proliferace buněk účinky léků MeSH
- sulfhydrylové sloučeniny chemie MeSH
- železo chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Iron oxide nanoparticles (IONPs) have a great potential with regard to cell labelling, cell tracking, cell separation, magnetic resonance imaging, magnetic hyperthermia, targeted drug and gene delivery. However, a growing body of research has raised concerns about the possible unwanted adverse cytotoxic effects of IONPs. In the present study, the in vitro cellular uptake, antiproliferative activity, cytotoxicity, genotoxicity, prooxidant, microtubule-disrupting and apoptosis-inducing effect of Fe3O4@SiO2 and passivated Fe3O4@SiO2-NH2 nanoparticles on human renal proximal tubule epithelial cells (HK-2) have been studied. Both investigated silica coated IONPs were found to have cell growth-inhibitory activity in a time- and dose-dependent manner. Determination of cell cycle phase distribution by flow cytometry demonstrated a G1 and G2/M phase accumulation of HK-2 cells. A tetrazolium salt cytotoxicity assay at 24 h following treatment demonstrated that cell viability was reduced in a dose-dependent manner. Microscopy observations showed that both Fe3O4@SiO2 and Fe3O4@SiO2-NH2 nanoparticles accumulated in cells and appeared to have microtubule-disrupting activity. Our study also revealed that short term 1 h exposure to 25 and 100 μg/mL of silica coated IONPs causes genotoxicity. Compared with vehicle control cells, a significantly higher amount of γH2AX foci correlating with an increase in DNA double-strand breaks was observed in Fe3O4@SiO2 and Fe3O4@SiO2-NH2-treated and immunestained HK-2 cells. The investigated nanoparticles did not trigger significant ROS generation and apoptosis-mediated cell death. In conclusion, these findings provide new insights into the cytotoxicity of silica coated IONPs that may support their further safer use.
- MeSH
- apoptóza účinky léků MeSH
- buněčné linie MeSH
- buněčný cyklus účinky léků MeSH
- dvouřetězcové zlomy DNA MeSH
- epitelové buňky účinky léků MeSH
- geny p53 MeSH
- histony genetika MeSH
- lidé MeSH
- magnetické nanočástice toxicita MeSH
- mikrotubuly účinky léků MeSH
- oxid křemičitý toxicita MeSH
- oxid železnato-železitý toxicita MeSH
- poškození DNA * MeSH
- povrchové vlastnosti MeSH
- proximální tubuly ledvin cytologie MeSH
- reaktivní formy kyslíku MeSH
- testy genotoxicity MeSH
- virová transformace buněk MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A upflow anaerobic sludge blanket reactor was operated combined to a membrane aerated biofilm reactor for sulfate removal and for elemental sulfur reclamation. A commercial silicon tube was used as an oxygen delivery diffuser. The process achieved high rates of sulfide removal from the liquid phase (90%). The hydrogen sulfide removal was influenced by the pH value and at pH value of 7.5, 98% of the H2S was removed. The elemental sulfur was observed inside the membrane, with content in the biomass of 21%. Through the massive sequencing of the samples, the microbial community diversity and the stratification of biomass inside the silicon tube was demonstrated, confirming the presence of sulfide-oxidizing bacteria on the membrane wall. The most important genera found related to the sulfur cycle were Sulfuricurvum, Geovibrio, Flexispira and Sulforospirillum.
- MeSH
- biofilmy MeSH
- bioreaktory MeSH
- odpadní voda * MeSH
- odpadní vody MeSH
- sulfan * MeSH
- sulfidy MeSH
- Publikační typ
- časopisecké články MeSH
Hydrogen sulfide is a toxic and usually undesirable by-product of the anaerobic treatment of sulfate-containing wastewater. It can be removed through microaeration, a simple and cost-effective method involving the application of oxygen-limiting conditions (i.e., dissolved oxygen below 0.1 mg L-1). However, the exact transformation pathways of sulfide under microaerobic conditions are still unclear. In this paper, batch experiments were performed to study biochemical and chemical sulfide oxidation under microaerobic conditions. The biochemical experiments were conducted using a strain of Sulfuricurvum kujiense. Under microaerobic conditions, the biochemical sulfide oxidation rate (in mg S L-1 d-1) was approximately 2.5 times faster than the chemical sulfide oxidation rate. Elemental sulfur was the major end-product of both biochemical and chemical sulfide oxidation. During biochemical sulfide oxidation elemental sulfur was in the form of white flakes, while during chemical sulfide oxidation elemental sulfur created a white suspension. Moreover, a mathematical model describing biochemical and chemical sulfide oxidation was developed and calibrated by the experimental results.
Partial nitritation/anammox can provide energy-efficient nitrogen removal from the main stream of municipal wastewater. The main bottleneck is the growth of nitrite oxidizing bacteria (NOB) at low temperatures (<15 °C). To produce effluent suitable for anammox, real municipal wastewater after anaerobic pretreatment was treated by enriched ammonium oxidizing bacteria (AOB) in suspended sludge SBR at 12 °C. NOB were continually washed out using aerobic duration control strategy (ADCS). Solids retention time was set to 9-16 days. Using this approach, average ammonia conversion higher than 57% at high oxidation rate of 0.4 ± 0.1 kg-N kg-VSS-1 d-1 was achieved for more than 100 days. Nitrite accumulation (N-NO2-/N-NOX) of 92% was maintained. Thus, consistently small amounts of present NOB were efficiently suppressed. Our mathematical model explained how ADCS enhanced the inhibition of NOB growth via NH3 and HNO2. This approach will produce effluent suitable for anammox even under winter conditions in mild climates.
- MeSH
- bioreaktory * MeSH
- dusík MeSH
- dusitany MeSH
- odpad tekutý - odstraňování * MeSH
- odpadní voda * MeSH
- odpadní vody MeSH
- Publikační typ
- časopisecké články MeSH
In this study a completely stirred tank reactor was used to study the effect of sulfide to nitrate (S/N) ratio on sulfide removal while nitrate was used as electron acceptor. Several S/N ratios were studied for this purpose ranging from 0.3 to 2.4 mol/mol. The complete sulfide removal was achieved when S/N ratio 0.85 mol/mol was used with the autotrophic denitrification efficiency up to 80 %. No nitrite accumulation was observed, and the main product of sulfide oxidation was sulfate. Dissimilatory nitrogen reduction to ammonia occurred and subsequently, elemental sulfur accumulated while S/N ratio was higher than 1.3 mol/mol. The specific autotrophic denitrification rates under S/N ratios 0.8 and 1.2 were 5 and 26 mg g(-1) h(-1) (N-NO3 (-), VSS), respectively. Thiobacillus denitrificans and Thiomicrospira denitrificans were detected in the reactor by fluorescent in situ hybridization, but their overall representation was not more than 5 % of the entire microbial populations.
- MeSH
- amoniak metabolismus MeSH
- bioreaktory mikrobiologie MeSH
- denitrifikace * MeSH
- dusičnany metabolismus MeSH
- dusík analýza MeSH
- Epsilonproteobacteria genetika izolace a purifikace metabolismus MeSH
- hybridizace in situ fluorescenční MeSH
- oxidace-redukce MeSH
- síra analýza MeSH
- sírany metabolismus MeSH
- sulfidy metabolismus MeSH
- Thiobacillus genetika izolace a purifikace metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The removal of hydrogen sulfide from biogas by microaeration was studied in Up-flow Anaerobic Sludge Blanket (UASB) reactors treating synthetic brewery wastewater. A fully anaerobic UASB reactor served as a control while air was dosed into a microaerobic UASB reactor (UMSB). After a year of operation, sulfur balance was described in both reactors. In UASB, sulfur was mainly presented in the effluent as sulfide (49%) and in biogas as hydrogen sulfide (34%). In UMSB, 74% of sulfur was detected in the effluent (41% being sulfide and 33% being elemental sulfur), 10% accumulated in headspace as elemental sulfur and 9% escaped in biogas as hydrogen sulfide. The efficiency of hydrogen sulfide removal in UMSB was on average 73%. Microaeration did not cause any decrease in COD removal or methanogenic activity in UMSB and the elemental sulfur produced by microaeration did not accumulate in granular sludge.
- MeSH
- anaerobní bakterie fyziologie MeSH
- analýza selhání vybavení MeSH
- bioreaktory mikrobiologie MeSH
- chemické látky znečišťující vodu izolace a purifikace metabolismus MeSH
- čištění vody přístrojové vybavení MeSH
- design vybavení MeSH
- methan metabolismus MeSH
- odpadní voda mikrobiologie MeSH
- odpadní vody mikrobiologie MeSH
- sulfan izolace a purifikace metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
