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1.
Food Chem ; 366: 130613, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34304136

RESUMO

A colorimetric and fluorescence dual-signal method based on sulfur quantum dots (SQDs) was established for determination of iron (II) (Fe2+) and H2O2 in foods. Due to the complexation of Fe2+ with SQD, Fe2+ can cause fluorescence quenching of SQDs, and the color of the mixed solution changed from light yellow to deep green. By use of Fenton reaction, H2O2 can restore the quenched fluorescence of SQDs, and the color of the mixture changed from green to colorless. The concentration of Fe2+ and H2O2 has a good linear relationship with the fluorescence intensity and absorbance in the range of 2.5-55 µM and 1.25-500 µM, and the detection limits were 1.41 µM and 0.54 µM, respectively. For determination of H2O2, the linear ranges were 1.17-1.97 mM and 0.867-1.50 mM, and the detection limits were 0.03 µM and 0.06 µM, respectively.


Assuntos
Pontos Quânticos , Colorimetria , Peróxido de Hidrogênio , Ferro , Enxofre
2.
Food Chem ; 367: 130741, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34399272

RESUMO

Volatile sulfur-containing compounds (VSCs) provide an important contribution to foods due to their special odors. In this study, VSCs in 21 cold-pressed rapeseed oils (CROs) from 9 regions in China were extracted and separated by headspace solid-phase microextraction combined with gas chromatography coupled with sulfur chemiluminescence detection. 19 VSCs were identified by authentic standards, and the total concentration of VSCs in all CROs ranged from 49.0 to 18129 µg/kg. Dimethyl sulfide (DMS), with its high odor activity value (7-14574), was the most significant aroma contributor to the CROs. Furthermore, S-methylmethionine (SMM) in rapeseed was first affirmed by ultra-performance liquid chromatography-tandem mass spectrometry and isotope quantitation. The positive correlation coefficient between DMS and SMM was 0.793 (p < 0.05), which confirmed SMM as a crucial precursor of DMS in CROs. This study provided a theoretical basis for selecting rapeseed materials by the distribution of essential VSCs and the source of DMS.


Assuntos
Compostos de Enxofre , Compostos Orgânicos Voláteis , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Cromatografia Gasosa-Espectrometria de Massas , Odorantes/análise , Óleo de Brassica napus , Sulfetos , Enxofre , Compostos de Enxofre/análise , Espectrometria de Massas em Tandem , Compostos Orgânicos Voláteis/análise
3.
Anal Chim Acta ; 1178: 338805, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482864

RESUMO

The development of real-time monitoring sensors for pyro-metallurgical processes is an analytical challenge, mainly due to adverse environmental conditions, high spectral interferences and multiphase (molten and gas) reactions. This work demonstrates the suitability of stand-off LIBS (ST-LIBS) for real time monitoring of the desulfurization of blister copper which is carried out in molten phase. Here sulfur is removed by the formation of SO2 by supplying oxygen in molten phase. Using ST-LIBS the relative emission intensities of Cu(I) at 351.06 nm, O at 777.34 nm and S at 921.29 nm in both molten and gaseous phase were considered simultaneously during the process. This was possible only by the use high energy laser pulse over up to 270 mJ per pulse. In the case of copper, the selection of emission lines was assessed considering non-linear behavior, which is caused by self-absorption. For the first time, real time determination of sulfur in ppm range is reported by ST-LIBS using low sensitive lines from the NIR region. These results were validated with differential optical absorption spectroscopy (DOAS) as gold standard method. The analytical information obtained by LIBS can precisely determine the critical end-point of the desulfurization where the removal of sulfur is finished, and copper started to oxidize.


Assuntos
Vesícula , Cobre , Humanos , Lasers , Análise Espectral , Enxofre
4.
Mar Pollut Bull ; 171: 112917, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34488148

RESUMO

Very Low Sulfur Fuel Oils (VSLFO, <0.5% S) are a new class of marine fuel oils, introduced to meet recent International Maritime Organization regulations. The MV Wakashio was reported to have released 1000 t of VLSFO when it grounded on a reef in Mauritius on 25th July 2020. A field sample of oily residue contaminating the Mauritian coast was collected on 16th August 2020 and compared with the Wakashio fuel oil. Both oils were analyzed for organic and elemental content, and stable isotope ratios δ13C and δ2H measured. Comprehensive two-dimensional gas chromatography with high-resolution mass spectrometry was used to identify and compare biomarkers resistant to weathering. The aromatic content in the VLSFO was relatively low suggesting that the potential for ecosystem harm arising from exposure to toxic components may be less than with traditional fuel oil spills. The Wakashio oil spill is, to our knowledge, the first documented spill involving VLSFO.


Assuntos
Óleos Combustíveis , Poluição por Petróleo , Ecossistema , Maurício , Enxofre
5.
Anal Chim Acta ; 1181: 338893, 2021 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-34556227

RESUMO

Development of selective, ultra-sensitive, rapid and facile methods for the detection of chemical residues of toxic pesticides and hazardous chemicals are quite important in food safety, environmental monitoring and safeguarding public health. Herein, we presented a fluorescent turn-on aptasensor based on sulphur-doped graphene quantum dot (S-GQD) utilizing specific recognition and binding property of aptamer for the ultra-sensitive and selective detection of omethoate (OM) which is a systemic organophosphorus pesticide. The detection method is based on tuning aggregation-disaggregation mechanism of S-GQD by way of conformational alteration of the recognition probe. Fluorescence 'turn-on' process includes aggregation-induced quenching of S-GQD with aptamer via S-GQD-aptamer complex formation and its subsequent fluorescence recovery with the addition of OM by structural switching of S-GQD-aptamer complex to aptamer-omethoate complex. The reported 'switch-on' aptasensor has exhibited a low limit of detection of 0.001 ppm with high selectivity for OM over other pesticides.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Grafite , Praguicidas , Pontos Quânticos , Dimetoato/análogos & derivados , Limite de Detecção , Compostos Organofosforados , Enxofre
6.
Nat Commun ; 12(1): 5308, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489463

RESUMO

Climate change is altering the frequency and severity of drought events. Recent evidence indicates that drought may produce legacy effects on soil microbial communities. However, it is unclear whether precedent drought events lead to ecological memory formation, i.e., the capacity of past events to influence current ecosystem response trajectories. Here, we utilize a long-term field experiment in a mountain grassland in central Austria with an experimental layout comparing 10 years of recurrent drought events to a single drought event and ambient conditions. We show that recurrent droughts increase the dissimilarity of microbial communities compared to control and single drought events, and enhance soil multifunctionality during drought (calculated via measurements of potential enzymatic activities, soil nutrients, microbial biomass stoichiometry and belowground net primary productivity). Our results indicate that soil microbial community composition changes in concert with its functioning, with consequences for soil processes. The formation of ecological memory in soil under recurrent drought may enhance the resilience of ecosystem functioning against future drought events.


Assuntos
Secas/estatística & dados numéricos , Microbiota/fisiologia , Microbiologia do Solo , Solo/química , Água/análise , Acidobacteria/classificação , Acidobacteria/genética , Acidobacteria/isolamento & purificação , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Altitude , Áustria , Bacteroidetes/classificação , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Biomassa , Carbono/análise , Chloroflexi/classificação , Chloroflexi/genética , Chloroflexi/isolamento & purificação , Pradaria , Humanos , Nitrogênio/análise , Fósforo/análise , Planctomycetales/classificação , Planctomycetales/genética , Planctomycetales/isolamento & purificação , Proteobactérias/classificação , Proteobactérias/genética , Proteobactérias/isolamento & purificação , Enxofre/análise , Verrucomicrobia/classificação , Verrucomicrobia/genética , Verrucomicrobia/isolamento & purificação
7.
Water Res ; 204: 117628, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34507021

RESUMO

Both biological sulfate reduction process and sulfur reduction process are attractive technologies for metal-laden wastewater treatment. However, the acidity stress of metal-laden wastewater could affect the sulfidogenic performance and the microbial community, weaken the stability, efficiency and cost-effectiveness of the biological sulfidogenic processes (BSP). In this study, long-term lab-scale trials were conducted with a sulfate-reducing bioreactor and a sulfur-reducing bioreactor to evaluate the effects of acidity on sulfidogenic activities and the microbial community of the BSP. In the 300-day trial, the sulfate-reducing bacteria (SRB)-driven BSP was stable in terms of sulfidogenic performance and microbial community with the decline of pH, while the sulfur-reducing bacteria (S0RB)-driven BSP achieved high-rate and low-cost sulfide production under neutral conditions but unstable under acidic conditions. With the decline of pH, the sulfide production rate (SPR) of the SRB-driven BSP stably increased from 30 to 83 mg S/L-h; while it decreased from 56 to 37 mg S/L-h in the S0RB-driven BSP with high fluctuation. The results of estimation were consistent with the thermodynamical calculations, in which the sulfur reduction process showed a better performance at pH 5-7, while the sulfate reduction process might gain more energy when pH<5. The stable sulfidogenic performance and microbial community diversity of the SRB-driven BSP could be attributed to the alkalinity produced in sulfate reduction to buffer the acidic stress. In comparison, the microbial community in the S0RB-driven BSP was significantly re-shaped by acidity stress, and the predominant sulfidogenic bacterium changed from Desulfovibrio at neutral condition, to Desulfurella at pH≤5.4. The stability of the microbial community significantly affected the SPR and the operational cost. Nevertheless, the organic consumption for sulfide production of the S0RB-driven BSP was still less than the SRB-driven BSP even in acidic conditions. Collectively, the S0RB-driven BSP was recommended under neutral or mild acid conditions, while the SRB-driven BSP was more suitable under fluctuating pH conditions, especially at low pH. Overall, this study presented the long-term performance of SRB- and S0RB-driven BSP under varying pH conditions, and provided guidance to determine the suitable BSP and operational cost for different metal-laden wastewater.


Assuntos
Enxofre , Águas Residuárias , Concentração de Íons de Hidrogênio , Metais , Sulfatos
8.
Ecotoxicol Environ Saf ; 225: 112765, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34530260

RESUMO

We aimed to investigate how sulfur (S) application prior to oilseed rape cultivation influences the uptake of cadmium (Cd) by rice grown in low- and high-Cd soils. A pot experiment involving four S levels (0, 30, 60, 120 mg S kg-1) combined with two Cd rates (low and high-0.35 and 10.35 mg Cd kg-1, respectively) was conducted. Soil pore water during rice growth and plant tissues at maturity were analyzed. The soil pore water results indicated that S application decreased Cd solubility under submergence due to the S-induced increase of soil pH and the enhancement of sulfide formation in soil micropores. When S was applied at rates of 30, 60 and 120 mg S kg-1, brown rice Cd concentrations decreased by 18%, 18%, and 55% (p < 0.05) in the low-Cd soil but increased by 20%, 40%, and 40% in the high-Cd soil compared with those in the non-S treatment. The different effects of S on Cd accumulation in brown rice were related to Cd-induced oxidative stress in the rice plants. In low-Cd soils, a S-induced increase in phytochelatins in rice roots restricted and inhibited Cd translocation in brown rice. In high-Cd soils, the Cd-induced oxidative stress in rice plants weakened the protective effects of S, while highlighted the promotion of Cd uptake by S. Overall, S fertilizer is recommended for oilseed rape-rice rotations in low-Cd paddy fields. In high Cd-contaminated fields, oilseed rape-rice rotations are suitable for the simultaneous remediation by oilseed rape and production of rice without S fertilization.


Assuntos
Brassica napus , Oryza , Poluentes do Solo , Cádmio/toxicidade , Solo , Poluentes do Solo/toxicidade , Enxofre
9.
Ecotoxicol Environ Saf ; 225: 112787, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34544020

RESUMO

Cadmium (Cd) contamination of croplands has become a threat to crop food safety and human health. In this study, we investigated the effect of sulfur on the growth of water spinach under Cd stress and the amount of Cd accumulation by increasing the soil sulfate content. We found that the biomass of water spinach significantly increased after the application of sulfur while the shoot Cd concentration was considerably reduced (by 31%). The results revealed that sulfur could promote the expression of PME and LAC genes, accompanied by an increase in PME activity and lignin content. Also, the cell wall Cd content of water spinach roots was significantly increased under sulfur treatment. This finding suggests that sulfur could enhance the adsorption capacity of Cd by promoting the generation of cell wall components, thereby inhibiting the transportation of Cd via the apoplastic pathway. In addition, the higher expression of Nramp5 under the Cd1S0 (concentration of Cd and sulfur are 2.58 and 101.31 mg/kg respectively) treatment led to increased Cd uptake. The CAX3 and ABC transporters and GST were expressed at higher levels along with a higher cysteine content and GSH/GSSR value under Cd1S1 (concentration of Cd and sulfur are 2.60 and 198.36 mg/kg respectively) treatment, which contribute to the Cd detoxification and promotion of Cd compartmentalization in root vacuoles, thereby reducing the translocation of Cd to the shoot via the symplastic pathway.


Assuntos
Ipomoea , Cádmio/toxicidade , Perfilação da Expressão Gênica , Humanos , Enxofre , Transportes
10.
J Environ Sci (China) ; 108: 96-106, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34465441

RESUMO

Hydrodechlorination is a promising technology for the remediation of water body contaminated with trichloroethylene (TCE). In this work, the liquid-phase hydrogenation of TCE by Raney Ni (R-Ni) and Pd/C under an open system have been studied, in which nascent H2 (Nas-H2) generated in situ from the cathode acted as a hydrogen source. Experimental results showed that TCE was completely eliminate from the solution through the synergistic effects of hydrodechlorination and air flotation due to the formation of continuous micro/nano-sized Nas-H2 bubbles from the cathode. Furthermore, the effects of inorganic anions and organic solvents on R-Ni and Pd/C hydrogenation activity were investigated, respectively. The results showed that NO3- and acetonitrile can form a competitive reaction with TCE; Sulfur with lone-pair electrons will cause irreversible poisoning to these two catalysts, and have a stronger inhibitory effect on Pd/C. This work helps to realize the separation of volatile halogenated compounds from water environment and provides certain data support for the choice of catalyst in the actual liquid-phase hydrogenation system.


Assuntos
Tricloroetileno , Catálise , Hidrogenação , Solventes , Enxofre
11.
J Biomed Nanotechnol ; 17(8): 1598-1611, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34544537

RESUMO

Multifunctional carbon dots have drawn considerable attention due to their potential biomedical application value. We report the preparation of blue-green fluorescence-emitting, multifunctional, nitrogen-and-sulfur co-doped carbon dots (N, S-CDs) synthesized via a one-step process using 1-thioglycerol as a sulfur source, glucose and citric acid as carbon sources, and polyethyleneimine as a nitrogen source. Because of abundant amino and sulfur content, the CDs exhibited high sensibility and selectivity for detecting Cu2+ (detection limit: 0.01 µM, linear range: 0.025 to 50 µM). Fast and sensitive detection of tiopronin was also achieved on the basis of the fluorescence "off-on" mode considering the strong affinity between tiopronin and Cu2+. The N, S-CDs exhibited good biocompatibility as determined by fluorescence imaging using onion epidermal cells and gram-positive bacteria. The CDs also exhibited excellent antimicrobial ability against the gram-positive bacteria. Our results indicate that these novel N, S-CDs could be ideal candidates for several biochemical applications such as antibacterial treatment and detection of small biomolecules.


Assuntos
Carbono , Pontos Quânticos , Corantes Fluorescentes , Nitrogênio , Espectrometria de Fluorescência , Enxofre
12.
Talanta ; 235: 122708, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517581

RESUMO

Conventional sulfur isotope measurements in complex natural liquid or solid samples via GS-IRMS are complicated, time consuming and relatively expensive. Here we assessed a novel 'collision cell' based ICP-MS/MS approach which can determine the sulfur isotope abundances (i.e., 34S/32S ratios, expressed as δ34S) in complex coastal waters rapidly, accurately and with minimal sample preparation. The approach was validated via repeated ICP-MS/MS measurement of S isotope certified reference materials (CRM) providing accurate and reproducible results, with a typical uncertainty on δ34S of around 1.1-1.5‰ (1SD). This novel approach is suitable for water samples with sulfur concentrations at or above 2 µg/mL (ppm). Matrix matching between samples and the CRM was necessary when seawater-like solutions were analysed addressing common matrix related errors. The ICP-MS/MS approach was used to investigate δ34S signature of porewaters from a variety of coastal systems in South Australia (including acid sulfate soils), and how they responded to progressive seawater inundation. Importantly, inundation induced a shift in S isotope ratio in affected porewaters in which δ34S approached that of seawater. The simple sample preparation, with rapid and accurate δ34S determination of complex natural waters using the ICP MS/MS approach, greatly increases the applicability of sulfur isotope tracing studies to identify and monitor sources and bio-geochemical pathways of S in coastal and near-surface environments.


Assuntos
Água do Mar , Espectrometria de Massas em Tandem , Isótopos , Enxofre , Isótopos de Enxofre/análise
13.
ACS Appl Mater Interfaces ; 13(33): 39135-39141, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34374274

RESUMO

Many physiochemical properties of the extracellular matrix (ECM) of muscle tissues, such as nanometer scale dimension, nanotopography, negative charge, and elasticity, must be carefully reproduced to fabricate scaffold materials mimicking muscle tissues. Hence, we developed a muscle tissue ECM-mimicking scaffold using Mo6S3I6 inorganic molecular wires (IMWs). Composed of bio-essential elements and having a nanofibrous structure with a diameter of ∼1 nm and a negative surface charge with high stability, Mo6S3I6 IMWs are ideal for mimicking natural ECM molecules. Once Mo6S3I6 IMWs were patterned on a polydimethylsiloxane surface with an elasticity of 1877.1 ± 22.2 kPa, that is, comparable to that of muscle tissues, the proliferation and α-tubulin expression of myoblasts enhanced significantly. Additionally, the repetitive one-dimensional patterns of Mo6S3I6 IMWs induced the alignment and stretching of myoblasts with enhanced α-tubulin expression and differentiation into myocytes. This study demonstrates that Mo6S3I6 IMWs are promising for mimicking the ECM of muscle tissues.


Assuntos
Materiais Biomiméticos/química , Dimetilpolisiloxanos/química , Matriz Extracelular/metabolismo , Nanofios/química , Tecidos Suporte/química , Materiais Biomiméticos/metabolismo , Diferenciação Celular , Proliferação de Células/efeitos dos fármacos , Humanos , Iodo/química , Molibdênio/química , Músculos/citologia , Mioblastos/citologia , Mioblastos/metabolismo , Enxofre/química , Propriedades de Superfície , Engenharia Tecidual , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo
14.
Analyst ; 146(17): 5287-5293, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34338251

RESUMO

A facile one-pot hydrothermal approach for synthesizing water-dispersed nitrogen and sulfur doped carbon dots (NS-CDs) with high luminescence quantum yield was explored, using cysteine and tryptophan as precursors. The NS-CDs were characterized by means of FT-IR spectroscopy, XRD, TEM, etc. It was found that the absolute photoluminescence quantum yield (QY) of the NS-CDs determined with an integrating sphere can reach up to 73%, with an average decay time of 17.06 ns. Electrochemiluminescence (ECL) behaviors and mechanisms of the NS-CDs/K2S2O8 coreactant system were investigated. When the working electrode was modified with the prepared NS-CDs, the ECL efficiency of the NS-CDs with K2S2O8 was 24%, relative to Ru(bpy)3Cl2/K2S2O8. This work shows great potential for the NS-CDs to be used in bioanalytical applications.


Assuntos
Carbono , Pontos Quânticos , Aminoácidos , Nitrogênio , Espectroscopia de Infravermelho com Transformada de Fourier , Enxofre , Água
15.
Huan Jing Ke Xue ; 42(9): 4267-4274, 2021 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-34414724

RESUMO

Karst water, which provides approximately 25% of the world's drinking water, is especially vulnerable to anthropogenic pollutants. To determine the variations between high and low flow periods and the sources of dissolved sulfate (SO42-) in small karst basins, SO42- concentrations, stable sulfur and oxygen isotopes (δ34S-SO4 and δ18O-SO4), and oxygen isotopes of water (δ18O-H2O) were investigated in surface and groundwaters, during the high and low flow seasons, within the Babu subterranean stream basin. Analysis showed that: ① the water samples that were directly impacted by acid mine drainage exhibited high SO42- concentrations (≥250 mg·L-1) and significant seasonal variation, while the seasonal variation of non-AMD-impacted water with low SO42- concentrations was not significant. ② During the high flow season, the mean δ34S-SO4 and δ18O-SO4 values of surface water were -10.5‰ and 4.7‰, respectively, and -11.5‰ and 1.3‰ during the low flow period; the mean values of δ34S-SO4 and δ18O-SO4 in groundwater samples were -2.9‰ and 7.1‰ during the high flow period, respectively, and -3.2‰ and 6.2‰ during the low flow period. Both surface and groundwater samples exhibited higher δ34S-SO4 and δ18O-SO4 values during the high flow period than during the low flow period. ③ The values of δ34S-SO4 in the surface and groundwater samples were relatively stable, indicating that the sources of SO42- at specific sampling sites were stable.④ The main sources of SO42- in surface and groundwaters were rain, sulfide, and gypsum, accounting for 13%, 40%, and 47%, respectively, of SO42- in samples taken from the basin outlet during the high flow season, and 18%, 39%, and 43%, respectively, in samples obtained during the low flow season.


Assuntos
Monitoramento Ambiental , Rios , Isótopos de Oxigênio/análise , Estações do Ano , Sulfatos/análise , Enxofre
16.
Ecotoxicol Environ Saf ; 223: 112606, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34365211

RESUMO

Heavy metal(loid) contamination represents an immense challenge in sustainable agriculture. Arsenic, in particular, poses a great risk to the quality of agricultural products (e.g., rice grain). The sulfur amendment is recommended as an effective practice to remediate heavy metal(loid)-polluted soil, given its function in enhancing crop production and alleviating heavy metal(loid) accumulation in the plant. This study aims to investigate the roles of sulfur fertilizer on arsenic accumulation in rice and to explore the key mechanisms. In this study, Elemental sulfur (ES) and gypsum sulfur (GS) were chosen as sulfur fertilizers, with different application rates (0, 0.15, and 0.30 g S kg-1 soil). The results showed that ES and GS treatment significantly increased rice grain yield by 46.6-59.7% and significantly reduced the rice grain arsenic content by more than 39.1%. The sulfur treatment decreased soil pe + pH values. ES treatment increased the availability of arsenic in the bulk soil, whereas GS showed little effect. Sulfur application promoted the formation of iron and manganese plaques, which could suppress the migration of arsenic from soil to rice root. In addition, the sulfur treatment decreased the arsenic that migrating from rice roots to grains by 33.3-66.7%. This study indicates that sulfur application could increase arsenic availability in paddy soil; however, it can inhibit arsenic accumulation in rice grains via increasing the root plaques content and inhibiting the translocation of arsenic from roots to grains.


Assuntos
Arsênio , Oryza , Poluentes do Solo , Arsênio/análise , Cádmio/análise , Sulfato de Cálcio , Fertilizantes , Solo , Poluentes do Solo/análise , Enxofre
17.
Commun Biol ; 4(1): 945, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362999

RESUMO

Two challenges that the global wheat industry is facing are a lowering nitrogen-use efficiency (NUE) and an increase in the reporting of wheat-protein related health issues. Sulphur deficiencies in soil has also been reported as a global issue. The current study used large-scale field and glasshouse experiments to investigate the sulphur fertilization impacts on sulphur deficient soil. Here we show that sulphur addition increased NUE by more than 20% through regulating glutamine synthetase. Alleviating the soil sulphur deficiency highly significantly reduced the amount of gliadin proteins indicating that soil sulphur levels may be related to the biosynthesis of proteins involved in wheat-induced human pathologies. The sulphur-dependent wheat gluten biosynthesis network was studied using transcriptome analysis and amino acid metabolomic pathway studies. The study concluded that sulphur deficiency in modern farming systems is not only having a profound negative impact on productivity but is also impacting on population health.


Assuntos
Agricultura/métodos , Fertilizantes/análise , Gliadina/metabolismo , Nitrogênio/metabolismo , Solo/química , Enxofre/administração & dosagem , Triticum/efeitos dos fármacos , Avaliação de Programas e Projetos de Saúde , Triticum/crescimento & desenvolvimento
18.
Bioresour Technol ; 340: 125699, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34391190

RESUMO

Sulfur autotrophic denitrification (SAD) is a promising technology due to its low cost and low sludge production. Based on previous studies on SAD materials as well as the denitrification mechanism of SAD technology, this study constructed two biofilters with a sulfur autotrophic denitrification composite filler (SADCF) to investigate the application potential of SAD technology. The feasibility of a SADCF-based biofilter was demonstrated, with a maximum nitrate volume load of 0.75 kg N/(m3·d) and low accumulation of nitrite and ammonium. In addition, an improved backwashing method (air-water backwashing) was obtained by comparing two different backwashing methods. Furthermore, some iron reducing bacteria (0.4% Geothrix) along with a rapid proliferation of the main sulfur-oxidizing bacteria (23.0% Thiobacillus and 27.7% Ferritrophicum) were found under real-world operating conditions. Overall, the results of this study provide a case reference for the operation of SADCF-based biofilters and the application of SAD technology in engineering.


Assuntos
Reatores Biológicos , Desnitrificação , Processos Autotróficos , Nitratos , Nitrogênio , Enxofre
19.
Sci Total Environ ; 798: 149186, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34375243

RESUMO

Re-inoculation was an effective way to improve bioleaching efficiency by enhancing the synergetic effects of biogenic Fe3+ coupling with S0 oxidation. However, the complex microbial interactions after re-inoculation have received far less attention, which was crucial to the bioleaching performances. Herein, the enriched ferrous oxidizers (FeO) or sulfur oxidizers (SO) were inoculated to chalcopyrite microcosm, then they were crossly re-inoculated again to characterize the interspecific interaction patterns. The results showed that the dominant species in Fe groups were Acidithiobacillus ferrooxidans, while A. thiooxidans predominated in S groups. Introducing FeO resulted in a great disturbance by shifting the community diversity and evenness significantly (p < 0.05). In comparison, the communities intensified by SO maintained the original composition and structures. Microbial networks were constructed positively and modularly. The networks intensified by FeO were less connected and complex with less nodes and edges, but showed faster responses to the re-inoculation disturbance reflected by shorter average path length. Interestingly, the genus Leptospirillum were identified as keystones in S groups, playing critical roles in iron-oxidizing with lots of sulfur oxidizers. The introduced sulfur oxidizers enhanced microbial cooperation, formed robust community with strong bio-dissolution capability, and harbored the highest bioleaching efficiency. These findings improved our understanding about the acidophiles interactions, which drive community functional responses to the re-inoculated bioleaching process.


Assuntos
Acidithiobacillus , Cobre , Oxirredução , Enxofre
20.
Biosens Bioelectron ; 193: 113540, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34403935

RESUMO

Synergistic dual-mode optical platforms are up-and-coming detection tools in the diagnosis and management of infectious diseases. Here, novel dual-modality fluorescence (FL) and surface-enhanced Raman scattering (SERS) techniques have been integrated into a single probe for the rapid and ultrasensitive detection of norovirus (NoV). The developed FL-SER-based biosensor relies on the dual-signal enhancements of newly synthesized sulfur-doped agar-derived carbon dots (S-agCDs). The antigen-antibody immunoreaction results in forming a core-satellite immunocomplex between anti-NoV antibody-conjugated S-agCDs and polydopamine-functionalized magnetic silver nanocubes [poly (dop)-MNPs-Ag NCs]. By deploying an immunomagnetic enrichment protocol and performing the SERS modality on a single-layer graphene substrate, norovirus-like particles (NoV-LPs) were detected across a wide range of 1 fg mL-1 - 10 ng mL-1 with an excellent limit of detection of 0.1 fg mL-1. The combined advantage of the dual-signaling properties of the biosensor was demonstrated using FL confocal imaging for "hotspots" tracking prior to SERS detection of clinical NoV in fecal specimen down to ⁓10 RNA copies mL-1. The proposed dual-modality biosensor's performance increases the prospect of a rapid and low-cost sensitive NoV detection and surveillance option for public health.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Norovirus , Carbono , Indóis , Limite de Detecção , Fenômenos Magnéticos , Polímeros , Prata , Análise Espectral Raman , Enxofre
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