Journal of Environmental Sciences
·
2020
·
IF 4.302
Xiaoyang Fan,Yili Wang,Daxin Zhang,Yajie Guo,Shihui Gao,Enrui Li,Huaili Zheng
The effects of four conditioning approaches: Acid, Acid-zero-valent iron (ZVI)/peroxydisulfate (PMS), Fe(II)/PMS and ZVI/PMS, on wastewater activated sludge (WAS) dewatering and organics distribution in supernatant and extracellular polymeric substances (EPS) layers were investigated. The highest reduction in bound water and the most WAS destruction was achieved by Acid-ZVI/PMS, and the optimum conditions were pH 3, ZVI dosage 0.15 g/g dry solid (DS), oxone dosage 0.07 g/g DS and reaction time 10.6 min with the reductions in capillary suction time (CST) and water content (Wc) as 19.67% and 8.49%, respectively. Four conditioning approaches could result in TOC increase in EPS layers and supernatant, and protein (PN) content in tightly bound EPS (TB-EPS). After conditioning, organics in EPS layers could migrate to supernatant. Polysaccharide (PS) was easier to migrate to supernatant than PN. In addition, Acid, Acid-ZVI/PMS or Fe(II)/PMS conditioning promoted the release of some polysaccharides containing ring vibrations v P O, v C-O-C, v C-O-P functional groups from TB-EPS. ESR spectra proved that both radicals of SO 4 - · and ·OH contributed to dewatering and organics transformation and migration. CST value of WAS positively correlated with the ratios of PN/PS in LB-EPS and total EPS, while it negatively correlated with TOC, PN content and PS content in TB-EPS, as well as PS content in supernatant and LB-EPS. BWC negatively correlated to zeta potential and TOC value, PN content, and HA content in supernatant.
研究领域:
环境科学
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污水处理
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DOI
PubMed
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Zhaobin Liu,Shiliang Heng,Qicai Dai,Yijing Gao,Yule Han,Lingtian Hu,Yisheng Liu,Xueqin Lu,Guangyin Zhen
Waste activated sludge properties vary widely with different regions due to the difference in living standards and geographical distribution, making a big challenge to developing a universally effective sludge dewatering technique. The Fe(II)-activated persulfate (S 2 O 8 2− ) oxidation process shows excellent ability to disrupt sludge cells and extracellular polymeric substances (EPS), and release bound water from sludge flocs. In this study, the discrepancies in the physicochemical characteristics of sludge samples from seven representative cities in China (e.g., dewaterability, EPS composition, surface charge, microbial community, relative abundance of antibiotic resistance genes (ARGs), etc.) were investigated, and the role of Fe(II)-S 2 O 8 2− oxidation in enhancing removal of antibiotic resistance genes and dewatering ability were explored. The results showed significant differences between the EPS distribution and chemical composition of sludge samples due to different treatment processes, effluent sources, and regions. The Fe(II)-S 2 O 8 2− oxidation pretreatment had a good enhancement of sludge dewatering capacity (up to 76 %). Microbial analysis showed that the microbial community in each sludge varied significantly depending on the types of wastewater, the wastewater treatment processes, and the regions, but Fe(II)-S 2 O 8 2− oxidation was able to attack and rupture the sludge zoogloea indiscriminately. Genetic analysis further showed that a considerable number of ARGs were detected in all of these sludge samples and that Fe(II)-S 2 O 8 2− oxidation was effective in removing ARGs by higher than 90 %. The highly active radicals (e.g., SO 4 − ·, ·OH) produced in this process caused drastic damage to sludge microbial cells and DNA stability while liberating the EPS/cell-bound water. Co-occurrence network analysis highlighted a positive correlation between population distribution and ARGs abundance, while variations in microbial communities were linked to regional differences in living standards and level of economic development. Despite these variations, the Fe(II)-S 2 O 8 2− oxidation consistently achieved excellent performance in both ARGs removal and sludge dewatering. The significant modularity of associations between different microbial communities also confirms its ability to reduce horizontal gene transfer (HGT) by scavenging microbes.
研究领域:
环境工程
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微生物学
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污水处理
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DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2025
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IF 6.7
Gongxu Zhang,Zheng Yao,Chenxi Zhang,Shuai Zhang,Helai Cheng
The removal of bound water remains one of the most significant challenges in sludge reduction. As classic predatory microorganisms, myxobacteria, exhibit broad-spectrum predatory activity against various organisms. However, it remains unclear whether myxobacteria can prey on sludge microorganisms and subsequently induce bound water release. This study demonstrates that the application of myxobacteria at different concentrations significantly reduced water content, total suspended solids (TSS), and volatile suspended solids (VSS) in sludge. Notably, the addition of Myxococcus xanthus DK1622 at 200 mg/L achieved a 0.85 % reduction in water content. At this optimal concentration, TSS and VSS decreased by up to 4.58 g/L and 2.29 g/L, respectively. The predation process induced significant changes in extracellular polymeric substances (EPS), with protein and polysaccharide concentrations increasing by 2.3-fold and 1.2-fold, respectively. These alterations were attributed to cellular material leakage during predation, which in turn contributed to EPS accumulation. Furthermore, the disruption of microbial aggregates via predatory activity facilitated the release of bound water from the sludge. These findings provide valuable insights for potential applications of myxobacteria in biological sludge dewatering processes.
研究领域:
环境微生物学
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污水处理
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生物污泥减量
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DOI
高影响因子
JOURNAL OF APPLIED MICROBIOLOGY
·
2019
·Vol. 127
·期 6
·1716-1726
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IF 2.683
Cheng R.,Wang L.,Li J.,Fu R.,Wang S.,Zhang J.
AimsTo purify and characterize an exopolysaccharide (EPS) from an Agrobacterium strain ZCC3656 with high EPS‐secreting performance and investigate its anti‐inflammatory activity using lipopolysaccharide (LPS)‐induced macrophage cells in an acute liver injury mouse model.Methods and ResultsTwelve rhizobial strains were compared for EPS fermentation production in modified M9 salts supplemented with mannitol or sucrose as the sole carbon source. Agrobacterium sp. ZCC3656 exhibited the highest EPS yield (21·1 g l−1) and was characterized for EPS production by carbon source utilization, time course fermentation and serial subcultivation assays. The EPS, designated Riclin, was purified by deproteinization using the Sevag method. The combined results of gel permeation chromatography, monosaccharide composition, methylation analysis and nuclear magnetic resonance analyses indicated that Riclin is a succinoglycan‐like polysaccharide comprised of glucose, galactose, succinate and pyruvate at a ratio of 7·8. : 1·0 : 0·9 : 1·1 and has an molecular weight of approximately 2·5 × 106 Da. Riclin inhibited TNF‐α, IL‐1β and IL‐6 expression in LPS‐stimulated RAW 264.7 macrophage cells in a dose‐dependent manner. In addition, Riclin pretreatment increased the survival rate of D‐Gal/LPS treated mice, inhibited serum ALT and AST activities and reduced the production of the inflammatory mediators TNF‐α, IL‐1β and IL‐6.ConclusionsAgrobacterium sp. ZCC3656 is a highly stable EPS‐producing strain. The EPS Riclin from ZCC3656 is a succinoglycan‐type polysaccharide that is noncytotoxic and exhibits remarkable anti‐inflammatory effects in vivo and in vitro.Significance and Impact of the StudySuccinoglycans are well known for good rheological properties and their physiological interactions with plants. However, their potential activity towards mammals has received little attention. Our study revealed that the succinoglycan Riclin exhibited excellent anti‐inflammatory activities and could be considered as a promising reagent in anti‐inflammatory treatment.
研究领域:
微生物学
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免疫学
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药理学
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DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Tong Wang,Dan Li,Xin Tian,Guolin Huang,Meilin He,Changhai Wang,Ali Nawaz Kumbhar,Abeselom Ghirmai Woldemicael
Salinity stress in estuarine environments poses a significant challenge for microalgal survival and proliferation. The interaction between microalgae and bacteria shows promise in alleviating the detrimental impacts of salinity stress on microalgae. Our study investigates this interaction by co-cultivating Chlorella sorokiniana , a freshwater microalga, with a marine growth-promoting bacterium Pseudomonas gessardii , both of which were isolated from estuary. In this study, bacteria were encapsulated using sodium alginate microspheres to establish an isolated co-culture system, preventing direct exposure between microalgae and bacteria. We evaluated microalgal responses to different salinities (5 PSU, 15 PSU) and interaction modes (free-living, gel-encapsulated), focusing on growth, photosynthesis, cellular metabolism, and extracellular polymeric substances (EPS) properties. High salinity inhibited microalgal proliferation, while gel-fixed interaction boosted Chlorella growth rate by 50.7 %. Both attached and free-living bacteria restored Chlorella 's NPQ to normal levels under salt stress. Microalgae in the free-living interaction group exhibited a significantly lower respiratory rate compared to the pure algae group (−17.2 %). Increased salinity led to enhanced EPS polysaccharide secretion by microalgae, particularly in interaction groups (19.7 %). Both salt stress and interaction increased the proportion of aromatic proteins in microalgae's EPS, enhancing its stability by modulating EPS glycosidic bond C-O-C and protein vibrations. This alteration caused microalgal cells to aggregate, free-living bacteria co-culture group, and fixed co-culture group increasing by 427.5 %, 567.1 %, and 704.1 %, respectively. In gel-fixed bacteria groups, reduced neutral lipids don't accumulate starch instead, carbon redirects to cellular growth, aiding salt stress mitigation. These synergistic activities between salinity and bacterial interactions are vital in mitigating salinity stress, improving the resilience and growth of microalgae in saline conditions. Our research sheds light on the mechanisms of microalgal-bacterial interactions in coping with salt stress, offering insights into the response of estuarine microorganisms to global environmental changes and their ecological stability.
研究领域:
微生物学
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环境科学
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海洋生物学
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植物生理学
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生物技术
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产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2023
·
IF 5.9
Song Li,Feng Zhao,Xueya Wang,Zhihua Liu,Jingze Guo,Yutong Li,Shuangmei Tan,Zhenxiang Xin,Shuai Zhao,Lin Li
Green flame retardants have drawn much attention because of their environmental friendliness. But for the high flame retardancy of flammable polymers, most existing green flame retardants are unsatisfactory, even the flame-retardant process can not achieve high efficiency and environmental protection. In this work, flame retardants and flame-retardant process are addressed in a two-pronged approach. An eco-friendly bio-based synergistic flame retardant (PAU) was synthesized based on phytic acid (PA) and urea (U) through simple complexation assembly in water. The designed flame retardant coating can be directly coated on the surface of any topological shape with polydopamine as an adhesive. Flame retardant expandable polystyrene (EPS-PAU) with light weight and high toughness is prepared with the designed PAU flame-retardant coating. The coated EPS plates exhibit V-0 UL-94 rating and 42.0 % of limited oxygen index and excellent smoke suppression. Moreover, the density of EPS-PAU is slightly increased only by 2.27 % on the basis of the neat EPS, and the hard shell formed using PDA as an adhesive layer is beneficial for the improvement of impact strength. This novel biomass-based PAU system provides a promising strategy for manufacturing polymer products with excellent flame retardancy, smoke inhibition and light weight.
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Wangbei Cao,Shiyu Fang,Qian Wu,Yang Wu,Leiyu Feng,Zhihuai Xie,Qian Feng,Fang Fang,Zhixiang Xu,Jingyang Luo,Yingqun Ma
Slow solubilization/hydrolysis efficiency has been widely recognized as a limiting factor for volatile fatty acids (VFAs) production from waste activated sludge (WAS) via anaerobic fermentation. This study developed an innovative choline chloride (ChCl)-based approach for WAS treatment. Accordingly, the VFAs yield was increased by 2.5–623.3%, which was attributed to the concurrent acceleration of WAS solubilization, hydrolysis, and acidification. Fourier transform infrared spectrometer (FTIR) and molecular docking analysis showed that ChCl can attack and disrupt extracellular polymeric substances (EPS) by forming hydrogen bonds with organics occurred in WAS ( i.e. proteins). More importantly, the generated VFAs in turn interacted with ChCl for in-situ deep eutectic solvents (DES)-like formation to significantly improve the organics dissolution of WAS for more bioavailable substrates associated with VFAs biosynthesis, and such effects were intensified with the VFAs level. Besides, ChCl exhibited “screening-effects” to enrich the hydrolytic and acidogenic anaerobes in WAS fermentation systems, while reduced VFAs-consumers. Meanwhile, the microbial metabolic profiles shift to favor the protein metabolism, and the genetic traits associated with extracellular and intracellular substrates metabolism, membrane transport, and fatty acid biosynthesis were all upregulated. Noteworthily, the functional hydrolytic and acidogenic species maintained their microbial activity for efficient VFAs production via quorum sensing (QS) and two-component systems (TCS) to counteract ChCl stress. The ranking efficiency product (REP) indices revealed that ChCl pretreatment showed a higher sustainable footprint (84.0%) over other traditional pretreatment approaches for WAS fermentation in view of both economic and environmental benefits. This work provides an innovative niche for efficient VFAs production from WAS with the sustainable application.
研究领域:
环境科学
·
微生物学
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DOI
高影响因子
Algal Research-Biomass Biofuels and Bioproducts
·
2017
·
IF 3.994
Yangyang Yang,Jun Hou,Peifang Wang,Chao Wang,Lingzhan Miao,Yanhui Ao,Yi Xu,Xun Wang,Bowen Lv,Guoxiang You,Zijun Yang
Heteroaggregation between magnetic nanoparticles (MNPs) and cells is a crucial precondition for the harvesting and separation of algae from the aquatic environment . However, separation mechanisms have not been fully elaborated in previous studies, especially regarding cyanobacteria coated with extracellular polymeric substances (EPS). The present study was conducted to investigate the interaction between PEI-coated iron-oxide nanoparticles (IONPs) and M. aeruginosa as a function of cell type (FACHB-1343 and FACHB-905) and cells with/without extracellular polymeric substances (EPS). The results demonstrated that harvesting efficiency (HE) varied with the different cell types with/without EPS surrounding the cyanobacteria. The PEI-coated IONPs showed higher HE for M9 than for M1 with the same mass ratio of NPs/cyanobacteria. Furthermore, EPS significantly affected the HE because of their heterogeneous composition, which was interpreted by spectral analysis and the DLVO theory. Overall, this study provides guidance on cyanobacteria harvesting with different environmental conditions when employing magnetic separation technology.
研究领域:
环境科学
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纳米技术
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水生生物学
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化学工程
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DOI
高影响因子
Food & Function
·
2021
·Vol. 13
·期 3
·1393-1407
·
IF 5.396
Liuming Xie,Zhibing Huang,Hui Meng,Zhibing Fan,Xiaoyi Shi,Jianhua Xie
Manipulating the structures, physicochemical properties, and monosaccharide compositions of exopolysaccharides (EPS) isolated from microorganisms has been reported to enhance their biological activities. Hence, the aim of this work was to examine the effects of genistein addition during fermentation on the amount, physicochemical properties, and immunomodulatory activity of EPS secreted by M. purpureus. Results showed that genistein addition significantly increased M. purpureus biomass and EPS yield to 2.42 g L−1 and 6.08 g L−1, respectively, and affected the physicochemical properties and structures of EPS. Furthermore, EPS produced by genistein-treated M. purpureus (G-EMP) improved the immunomodulatory activity of RAW264.7 macrophages by increasing the secretion of nitric oxide and cytokines. Moreover, phospho-Jun N-terminal kinase (p-JNK), phospho-extracellular regulated protein kinase (p-ERK), phospho-p38 (p-p38) mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) phospho-p65 (p65) proteins were remarkably upregulated by G-EMP stimulation, blocking Toll-like receptor 4 (TLR4) that dramatically reduced the pinocytic and phagocytic capacities. Overall, these findings provide potential rationales for the application of genistein in improving the EPS yield of M. purpureus.
研究领域:
微生物学
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免疫学
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生物技术
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Yimin Xie,Yihuai Huang,Zhiwei Liang,Hojae Shim
Waste scrap tyre as microbial immobilization matrix enhanced degradation of phthalate esters (PAEs), di (2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and diethyl phthalate (DEP). The hybrid (physical adsorption and microbial immobilization) degradation process performance of scrap tyres was examined for the PAEs degradation. The scrap tyre was shown with competitive adsorption capacity toward PAEs, influenced by pH, temperature, dosage of adsorbent (scrap tyre), and concentration of PAE. The primary adsorption mechanism for tyres toward PAEs was considered hydrophobic. The immobilization of previously isolated Bacillus sp. MY156 on tyre surface significantly enhanced PAEs degradation as well as bacterial growth. The enzymatic activity results implied immobilization promoted dehydrogenase activity and decreased esterase activity. The cell surface response during PAEs degradation, in terms of morphological observation, FTIR and XRD analyses, and extracellular polymeric substance (EPS) release, was further assessed to better understand the interactions between microorganisms and tyre surface. Waste scrap tyres could be a promising potential candidate to be reused for sustainable environmental management, including contaminants removal.
研究领域:
环境科学
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水处理
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微生物学
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材料科学
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可持续发展
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Zhao Wang,Junfeng Su,Amjad Ali,Ruijie Zhang,Wenshuo Yang,Liang Xu,Tingbao Zhao
A simultaneous denitrifying and mineralizing bacterium, Pseudomonas sp. WZ39 was isolated for fluoride (F − ), nitrate (NO 3 − -N), and calcium (Ca 2+ ) removal. Strain WZ39 exhibited a remarkable defluoridation efficiency of 87.49% under a pH of 6.90, F − and Ca 2+ concentration of 1.99 and 201.88 mg L −1 , respectively. EEM, SEM–EDS, XRD, and FTIR analyses elucidated the chemical adsorption and co-precipitation with calcium salt contributed to the removal of F − . The mechanisms of biomineralization were also investigated by determining the role of bound and unbound extracellular polymeric substances (EPS), cell wall, and calcium channel in nucleation. The results showed that bacteria can promote nucleation on the templates of cell walls or EPS through the electrostatic effect. The presence of the calcium channel blocker inhibited the transport of intracellular Ca 2+ to the extracellular environment. The outcome of the present research can provide a theoretical basis for the understanding of MICP phenomenon and the efficient treatment of F − containing groundwater.
研究领域:
环境微生物学
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水处理工程
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生物地球化学
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DOI
PubMed
高影响因子
ACS ES&T Water
·
2025
·
IF 4.3
Xin-Run Sun,Wan-Song Zong,Lingqiang Kong,Xiang Chen,Mei-Yan Liu,Su-Chun Wang,Peng-Fei Xia,Xian-Zheng Yuan,Li-Juan Feng
Bisphenol A (BPA) is a pervasive environmental contaminant known for its detrimental effects on human health. However, its impact on multiple generations of microorganisms and the biogeochemical cycles they mediate, particularly at environmentally relevant concentrations, remains poorly understood. This study explores the effects of BPA on Roseovarius nubinhibens, a crucial bacterium in the global sulfur cycle, under both short-term (F0 generation) exposure at the observed-effect concentration (26 mg/L) and long-term (F20 generation) exposure at an environmentally relevant concentration (0.06 mg/L). Short-term exposure to the observed-effect concentration significantly inhibited bacterial growth by 12.9%, while long-term exposure at the environmentally relevant concentration induced notable morphological changes without affecting growth. BPA at the observed-effect concentration also disrupted extracellular polymeric substance (EPS) production and protein structures, particularly in the soluble-EPS (S-EPS) fraction, leading to impaired bacterial flocculation. Additionally, BPA at both exposure levels decelerated the conversion of dimethylsulfoniopropionate (DMSP), with the observed-effect concentration particularly affecting the cleavage pathway, reducing dimethyl sulfide (DMS) production. This study provides the first direct experimental evidence that BPA disrupts the metabolic equilibrium of sulfur cycling. These findings underscore the need for deeper exploration of BPA’s environmental risks, especially at environmentally relevant concentrations, and its potential to interfere with microbial-driven sulfur biogeochemistry.
研究领域:
环境微生物学
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生物地球化学
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海洋微生物学
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毒理学
·
微生物生态学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）