Journal of Cleaner Production
·
2023
·
IF 11.1
Shu Wang,Nanqi Ren,Danhui Liang,Jifei Chang,Xin Wang,Jiaguo Yan,Xiang Cheng,Lili Dong,Nan Li
Vivianite is an important bio-induced product of dissimilated iron reduction (DIR), which exists widely in activated sludge and digested sludge of wastewater treatment plants (WWTPs). Extracellular polymeric substances (EPS) surrounding dissimilatory iron-reducing bacteria (DIRB) were reported to be transient media for microbial extracellular electron transfer (EET) and DIR. However, what happens when a layer of EPS envelops microbial cells during vivianite recovery? This study tried to assess the relationship between iron reduction and electron transfer by stripping EPS layer-by-layer, then clarified the delamination of different EPS layers on the performance of vivianite recovery. After stripping total EPS (PC-EPS batches) of DIRB, the Fe (III) reduction efficiencies ( R Fe ), Fe (III) reduction rate ( V Fe ), and vivianite formation efficiency ( R V ) decreased by 33%, 37%, and 30%, respectively. Tightly bound-EPS (TB-EPS) was confirmed to play a crucial role in vivianite formation, which contributed 28–51% to vivianite recovery and 34–55% to iron reduction. Electronic shuttle substances were contained in TB-EPS, which enhanced the EET rate and efficiency between cells and Fe (III). The polysaccharide content of TB-EPS was positively related to adhesiveness between cells and mineral, as well as the iron reduction efficiency. Furthermore, redox proteins (PpcA, OmcB) were embedded in EPS, which shortened the distance of electron hopping to across the EPS layer and further accelerated vivianite recovery from wastewater. Long-term operation of anaerobic reactors confirmed that TB-EPS played critical roles in bio-induced vivianite formation.
研究领域:
环境科学
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微生物学
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污水处理
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生物地球化学
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DOI
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Xueliang Zhang,Gisele LaPointe,Yang Liu,Xiaomeng Wang,Luyao Xiao,Xiaogan Zhao,Wei Li
In this study, we evaluated the impact of Lactiplantibacillus plantarum ( L. plantarum ) with ropy and non-ropy phenotypes on gel structure and protein conformation of fermented milk. Ropy L. plantarum (T1 & CL80) secreted EPS with high molecular weight (1.41 × 10 6 , 1.19 × 10 6 Da) and intrinsic viscosity (486.46, 316.32 mL/g), effectively enhances fermented milk viscosity and water holding capacity (WHC) (65.4%, 84.6%) by forming a dense gel structure. Non-ropy L. plantarum (CSK & S-1A) fermented milk gel’s high surface hydrophobicity and free sulfhydryl content caused high hardness and low WHC. Raman spectroscopy combined with circular dichroism analysis showed that high levels of α-helix (29.32–30.31%) and random roil (23.06–25.36%) protein structures are the intrinsic factors that contribute to the difference among fermented milk gels of ropy and non-ropy strains. This study provides a basis for understanding the structural variability of fermented milk gels using ropy or non-ropy lactic acid bacteria.
研究领域:
食品科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 55
·83211-83219
·
IF 5.19
Yin Li,Wang Juan,Shi Kaipian,Zhang Yong,Xu Ying,Kong Desheng,Ni Lixiao,Li Shiyin
The protective mechanism of extracellular polymeric substance (EPS) secreted by a harmful cyanobacteria against tannins allelochemicals was explored in this study. The binding properties of soluble EPS (SEPS) and bound EPS (BEPS) of Microcystis aeruginosa to tannic acid (TA) were investigated via fluorescence spectroscopy. The results suggested that TA interacted with the proteins in SEPS and BEPS mainly with binding constants of 5.26 and 7.93 L/mol, respectively; TA interacted with the humic acids in SEPS and BEPS mainly with binding constants of 5.12 and 5.24 L/mol, respectively. Thermodynamic experiments confirmed that the binding was mainly controlled by the hydrophobic force. Combined with Fourier transform infrared spectroscopy, it was found that the amine, carbonyl, carboxyl, and hydroxyl groups in EPS were the main functional groups contributing to the interaction of TA with EPS. The existence of EPS reduced the toxicity of TA to algal cells, with the 96 h inhibition rate of 40 mg L −1 TA on algal cells decreasing by 48.95%. The results of this study may improve our understanding of the protective mechanism of cyanobacteria against tannins allelochemicals.
研究领域:
环境科学
·
水生生物学
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生态学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yongze Li,Yazhou Tang,Yuchen Yang,Wenxiang Zhou,Chujie Qi,Kai Zhou,Bo Bian
Existing cyanobacteria thickening and dewatering processes in Taihu Lake commonly use conventional inorganic flocculants to condition the cyanobacteria, which poses certain environmental risks. In this study, three different types of typical flocculants, namely polymerized aluminum chloride (PAC), cationic polyacrylamide (CPAM) and starch-based flocculant (St-CTA), were selected to investigate their flocculant effects on cyanobacteria and the mechanism of action. The analysis showed that the dosage of St-CTA was low, the flocculation efficiency was high, and it could form flocs with large particle size and high strength. The adsorption and precipitation effect of St-CTA on protein and polysaccharide in flocculated EPS was stronger than that of CPAM and PAC, and it was able to act on the protein structure of EPS favorable for flocculation, improve the hydrophilic effect of S-EPS and LB-EPS, and reduce the content of bound water in EPS from 2.08 to 1.22 g/g DS, thus improving the efficiency of algae-water separation. The free energy and energy barrier of the EPS surface in each layer of the cyanobacterial floc after flocculation by St-CTA were significantly reduced, which resulted in the tendency of the cyanobacterial particles to aggregate and thus flocculate and settle. The pilot validation of St-CTA for cyanobacteria dewatering showed that the water content of algal residue could be reduced to 93.48 %, and the removal efficiencies of total nitrogen (TN), total phosphorus (TP), ammoniacal nitrogen (NH 3 -N), and chemical oxygen demand (COD) in the air-floated water could be up to 27.3 %, 76.6 %, 27.4 %, and 56.4 %, respectively. In conclusion, this study provides scientific knowledge and demonstration for promoting the use of St-CTA to condition cyanobacterial thickening and dewatering, which is a new idea to solve the problem of cyanobacterial resourcefulness and safe utilization.
研究领域:
环境科学
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生物学
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产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2026
·
IF 8.2
Jiaji Ye,Taolve Chi,Meijin Xu,Zhendi Yu,Chifei Dong,Lingtao Sun,Lanping Wei,Haiyun Zhou,Zhongyi Qi,Baolan Hu,Dongqing Cheng
NoV persisted in swine compost and throughout the WWTS treatment train. • NoV annual infection risk up to 2.5% (splash) after swine wastewater treatment. • NoV persistence may be correlated with Sphingobacterium abundance. • Sphingobacterium enhances NoV tolerance to heat, UV and chlorine disinfection. • EPS binds NoV P-domain by hydrogen bonding for adhesion and shielding. Norovirus (NoV) is a major cause of epidemic acute gastroenteritis worldwide, and contaminated food and water are important routes of NoV transmission. However, the environmental fate of NoV and the factors contributing to its persistence remain poorly understood. This study investigated NoV occurrence in small-scale swine farm compost and intensive swine wastewater treatment systems (WWTSs), and explored the potential bacterial factors associated with viral persistence. NoV was detected in swine compost, with Sphingobacterium co-occurring in NoV-positive samples but not in NoV-negative samples. In an intensive swine WWTS, NoV remained detectable throughout all treatment units, with 10 7.3 copies L −1 in the influent and 10 2.4 copies L −1 still present in the final effluent. Scenario-based QMRA indicated that splash ingestion represented the dominant exposure pathway, with an estimated annual potential infection risk of 2.5%. Sphingobacterium abundance was positively associated with NoV loads across treatment units. Under heat, ultraviolet, and chlorine stress, Sphingobacterium -associated NoV showed up to 6.6-, 5.6-, and 2.5-fold higher RNA retention, respectively, and stronger infectivity than bacteria-free controls. Adhesion assays, transmission electron microscopy observation, and molecular docking suggested that Sphingobacterium extracellular polysaccharides (EPS) may interact with the NoV capsid P domain via hydrogen bonding, supporting a putative EPS-associated protective pathway. These findings suggest that Sphingobacterium -mediated EPS shielding may contribute to NoV persistence and disinfection tolerance in swine-farm waste systems, highlighting the need to integrate microbial control and routine NoV monitoring into viral-risk management strategies. Download: Download high-res image (327KB) Download: Download full-size image
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DOI
高影响因子
PROCESS BIOCHEMISTRY
·
2017
·
IF 2.497
Li Liu,Qingyuan Hu,Yang Le,Guowei Chen,Zilin Tong,Qiao Xu,Gang Wang
Microbial surface adhesion to surfaces and subsequent biofilm establishment are ubiquitous in drinking water systems, which often contribute to deteriorated water quality. Disinfectants are common agents applied to drinking water controlling microbial propagation, yet the underlying mechanisms of how disinfectants function to regulate microbial activity and thereby biofilm development remains elusive. We experimentally studied the effects of chlorination on extracellular polymeric substance (EPS) production, and its impacts on early-stage biofilm formation in a model drinking water system. Results showed that low-level chlorine (≤ 1.0 mg/L) stimulated microbial EPS (especially of proteins) excretion that favored early-stage biofilm formation. Microbes experiencing higher chlorination (>1.0 mg/L) exhibited clearly suppressed growth associated with reduced EPS release, consequently yielding less biofilm formation. Removal of cell-attached proteins and polysaccharides diminished biofilm formation, which highlighted the critical role of EPS (especially protein components) in biofilm development. A negative correlation between chlorination-mediated microbial protein production and cell surface charge suggested that chlorine disinfection may modify cell surface properties through regulation of microbial EPS excretion and thereby mediate biofilm formation. With these quantitative estimations, this study provides novel insights into how chlorination-mediated EPS excretion shapes early-stage biofilm formation, which is essential for practical functioning of drinking water systems.
研究领域:
微生物学
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环境科学
·
水处理工程
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Yu Cheng,Quanbo Yu,Weihua Zhang,Zhiqiang Liu,Jue Ding,Hongzhe Pan,Yiping Li,Dan Wu,Minghua Zhu,Xianchuan Xie,Ningyuan Zhu
Multispecies biofilm exhibited high resistance to nanotoxicity by secreting extracellular polymeric substances (EPS) and undergoing alterations in the community composition. Scarce information was available to assess how these changes could further influence the transfer of nanoparticles (NPs) through the biofilm-based food chain. Photic biofilm was exposed to two distinct NPs (ZnO and TiO 2 ) and subsequently grazed by snails. Exposure to different NPs led to variations in biomass, chlorophyll content, EPS productivity, alpha diversity, and community composition of the photic biofilm. The presence of ZnO NPs facilitated the growth of phylum Cyanobacteria while TiO 2 promoted EPS productivity of photic biofilm. EPS were capable of embedding NPs (TiO 2 and ZnO) within its matrix, thereby mitigating their aggregation within the biofilm matrix. These alterations were subsequently confirmed to have an impact on the trophic transfer factors (TTF) of NPs through the constructed biofilm-snail food chain. The TTF of ZnO was lower than that of TiO 2 in feeding scenario 1 (only fed on TiO 2 or ZnO biofilm) but higher than that of TiO 2 in feeding scenario 2 (fed on TiO 2 and ZnO biofilm simultaneously), which was attributed to the shifts in the algae composition and a smaller size of ZnO NPs in EPS. This study demonstrated that the response of photic biofilm to NPs further affected the TTFs of NPs through the food chain.
研究领域:
生态学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FIRE SAFETY JOURNAL
·
2023
·
IF 3.1
Liang Zhou,Zhicheng Xu,Wenjie Xu,Huiling Jiang,Wenting Xu
A novel approach was used to prepare a new expanded polystyrene (EPS) composite based on calcium sulphate hemihydrate that significantly improves its fire performance. Negative pressure was applied to open cavities between the EPS beads and promoted the absorption of flame retardant slurry. Three fire retardant EPS (FR-EPS) composites with different densities were obtained. Although, a large number of inorganic additives were added, causing the increase in thermal conductivity to 0.043–0.045 W/(m∙K) and water absorption to 4.7–5.8%, the properties remained within an acceptable range. The results of limiting oxygen index (LOI), UL-94 vertical burning and Cone Calorimeter tests revealed that the FR-EPS1 increased LOI from 18.1% to 35.8%, achieved UL94 V-0 grade, decreased PHRR from 384.12 to 81.39 kW/m 2 , and reduced PSPR from 0.159 to 0.014 m 2 /s. With the continued increase of sample density, the measured LOI was further improved, while heat release and smoke production were better suppressed. TG results, and carbon residue after burning indicate that the endothermic dehydration reaction of calcium sulphate dihydrate and the physical barrier effect of the carbonaceous layer contribute to the extraordinary flame retardancy and smoke suppression of the FR-EPS composites.
研究领域:
材料科学
·
防火工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Dian Dai,Mingxiang Qv,Dongyang Liu,Chunming Tang,Wei Wang,Qirui Wu,Zhihong Yin,Liandong Zhu
Magnetic harvesting of microalgae depends on the interface interactions between microalgal cells and flocculants, and thus it is important to find a reasonable evaluation method understand these interface interactions. In this effort, we discussed the formation mechanism and pH regulation of microalgae magnetic harvesting via magnetic chitosan (Fe 3 O 4 @SiO 2 -CS) synthesized by a micro-emulsion method. The flocculation performances and mechanisms during the harvesting of microalgae by the novel flocculant were evaluated. The synthesis process and structure were determined by XRD, FT-IR, SEM and XPS, and the results indicated that Fe 3 O 4 @SiO 2 -CS was successfully prepared. The collection efficiency of 96.52 % was achieved for Chlorella vulgaris within 3 min using Fe 3 O 4 @SiO 2 -CS with the Fe 3 O 4 @SiO 2 and CS mass ratio of 1:3 under pH 1.0. Moreover, this study introduced the two-dimension fractal dimension and extended Derjaguin-Landau-Verwey-Overbeek (E-DLVO) model to evaluate the harvesting performances and mechanisms of Fe 3 O 4 @SiO 2 -CS. Experimental results showed that a strong electrostatic interaction was formed under acidic conditions between Fe 3 O 4 @SiO 2 -CS and microalgae cells with D 2 = 1.82 (fractal dimension value). The hydrophobic tryptophan-like amino acid was observed in the slime-extracellular polymeric substances (S-EPS) secreted by microalgae. S-EPS was found to be a significant substance to promote harvesting performance when the system was neutral or alkaline. This work provides deeper insights into microalgae harvesting by Fe 3 O 4 @SiO 2 -CS as well as reasonable mechanisms to illustrate the interaction of Fe 3 O 4 @SiO 2 -CS and microalgae under different pH values.
研究领域:
环境科学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2023
·Vol. 13
·期 1
·1-16
·
IF 4.6
Shen Shaohang,Wei Hua,Pan Yu,Hu Pan,Yang Hu
Coagulation/flocculation is one of the most widely used and cost-effective pretreatment methods for improving the dewaterability of sludge. In this study, a cationic modified starch-based flocculant (St-CTA) in conjunction with a popular clay, attapulgite (ATP), was used for the conditioning of waste-activated sludge. The dewatering properties, including the filter cake moisture content, filtration specific resistance, capillary suction time, filtration rate and compressibility coefficient, were measured and compared by varying the doses of St-CTA and ATP. By combination of the apparent dewatering performance and the changes in the contents and distributions of the extracellular polymeric substance (EPS) fractions and components, sludge flocs, and microstructures of sludge cakes, the dewatering mechanisms were discussed in detail. St-CTA in conjunction with ATP can exhibit an enhanced dewaterability of sludge and the water content in final sludge cake can be stably reduced below 80% owing to the synergistic effects of St-CTA and ATP. In addition to the efficient charge neutralization of St-CTA, ATP not only acts as a skeleton builder in the sludge dewatering process which makes the sludge flocs more compact and improves the filterability and permeability, but also tightly interacts with the proteins in EPS of the sludge which reduces the protein content and further enhances the dewatering effect. This study provides an economical, green, and effective way to further improve the dewaterability of sludge.
研究领域:
环境科学
·
污水处理
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Huimin Tian,Yachun Gu,Zili Lv,Liang Wang
Yoghurt fermented by Leuconostoc mesenteroides XR1 from Kefir grains was found to produce a unique silk drawing phenomenon. This property was found to be associated with the exopolysaccharides (EPS), X-EPS, produced by strain XR1. In order to better understand the mechanism that produced this phenomenon, the X-EPS was extracted, purified and characterized. The molecular weight and monosaccharide composition were determined by size exclusion chromatography coupled with multi-angle laser light scattering (SEC-MALLS) and ion chromatography (IC) analysis, respectively. The results showed that its molecular weight was 4.183 × 10 6 g/mol and its monosaccharide composition was glucose, and glucuronic acid , with the contents of 567.6148 and 0.2096 μg/mg, respectively. FT-IR and NMR analyses showed that X-EPS was an α-pyranose polysaccharide and was composed of 92.22 % α-(1 → 6) linked d -glucopyranose units and 7.77 % α-(1 → 3) branching. Furthermore, it showed a chain-like microstructure with branches in atomic force microscopy (AFM) and scanning electron microscopy (SEM) experiments. These results suggested that the unique structure of X-EPS, gave the yoghurt a strong viscosity and cohesiveness, which resulted in the silk drawing phenomenon. This work suggested that X-EPS holds the potential for food and industrial applications.
研究领域:
食品科学
·
微生物学
·
聚合物化学
·
生物技术
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产品关联
DOI
PubMed
高影响因子
PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY
·
2025
·
IF 1.9
Shuhan Yang,Shouqi Zhao,Yingying Ning,Dan Zhao
Previous studies have shown that co-culture methods can enhance exopolysaccharide production, no studies have reported this enhancement in co-cultures between Weissella confusa and Candida shehatae. This study developed an efficient co-culture system combining W. confusa XG-3 and C. shehatae (1:1 ratio), and employed response surface methodology to optimize both exopolysaccharide yield and properties. The initial co-culture produced 56.82 ± 0.12 g/L exopolysaccharide, a 1.63-fold increase over single culture. Optimization (sucrose: 105.97 g/L; yeast extract: 5.81 g/L; peptone: 6.24 g/L) further increased the yield to 115.66 g/L, a 2.04-fold improvement. The co-cultured exopolysaccharide had high water solubility (60.45 ± 0.70%) and water holding capacity (614.74 ± 9.26%). The co-cultured EPS showed significant antioxidant activity. At 5 mg/mL, the scavenging rates of ABTS, DPPH, hydroxyl, superoxide, H2O2 and total reducing power reached the highest 52.22 ± 0.47%, 50.79 ± 2.86%, 55.80 ± 2.56%, 36.05 ± 2.07%, 66.85 ± 0.30%, and 0.39 ± 0.01. It also had a superior effect on the proliferation of several probiotics compared with commercial prebiotics and exhibited high thermostability with a degradation threshold at 292.5 °C. These results demonstrate a novel, scalable strategy for producing multifunctional EPS with broad applications in the food industry.
研究领域:
微生物学
·
食品科学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）