Shengni Tian , Yufei Dong , Shouyang Pang , Guokai Yuan , Sisi Cai , Penghui Zhang , Yupeng Chen , Mingzhu Zhang
{"title":"Driving role of acid mine drainage on microbial community assembly and species coexistence in paddy soil profiles","authors":"Shengni Tian , Yufei Dong , Shouyang Pang , Guokai Yuan , Sisi Cai , Penghui Zhang , Yupeng Chen , Mingzhu Zhang","doi":"10.1016/j.jes.2024.12.034","DOIUrl":"10.1016/j.jes.2024.12.034","url":null,"abstract":"<div><div>The environmental impacts of acid mine drainage (AMD) from open-pit mining are profoundly detrimental, yet knowledge about its effects on paddy soil microbial communities, especially at greater depths, remains limited. In this investigation, we compared soils affected by AMD versus unaffected soil depth profiles in terms of bacterial diversity and community assembly. The profiles in AMD-polluted soils exhibited tight geochemical gradients, characterized by increased acidity, SO<sub>4</sub><sup>2-</sup>, NO<sub>3</sub><sup>-</sup>, and heavy metal content compared to unpolluted soils. Notably, AMD significantly diminished soil bacterial biodiversity. A depth-wise analysis showed distinct microbial stratification, with certain bacteria like <em>Candidatus_Solibacter</em> and <em>Candidatus_Koribacter</em> predominated in polluted soils, while others like <em>Haliangium</em> and <em>Nitrospira</em> were more prevalent in control soils. Interestingly, despite variable soil conditions, predicted metabolic pathways, particularly those involving carbon, nitrogen, and sulfur, showed relative stability. AMD pollution induced the upregulation of methyl-coenzyme M reductase and sulfate reductase genes. Bacterial communities were more responsive to pH and nutrient content rather than heavy metals, with pH and SO<sub>4</sub><sup>2-</sup> being the primary drivers of microbial diversity and distribution. Additionally, pH was identified as the most significant influence on the predicted methane, sulfur, and nitrogen metabolism. Furthermore, deterministic processes played a more significant role in community assembly of polluted soils, while heterogeneous selection gained importance with increasing depth in control soils. Additionally, microbial co-occurrences, particularly positive interactions, were more prevalent in the polluted soils with reduced network modularity and keystone taxa. These findings offer insights into sustaining microbial diversity in extreme environments.</div></div>","PeriodicalId":15788,"journal":{"name":"Journal of Environmental Sciences-china","volume":"156 ","pages":"Pages 771-783"},"PeriodicalIF":5.9,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yanshen Zhang , Bin Liu , Wanling Wu , Haopeng Liu , Wen Wang
{"title":"Propanol as electron donor for efficient odd-chain carboxylate production by chain elongation with reactor microbiomes","authors":"Yanshen Zhang , Bin Liu , Wanling Wu , Haopeng Liu , Wen Wang","doi":"10.1016/j.jes.2024.12.033","DOIUrl":"10.1016/j.jes.2024.12.033","url":null,"abstract":"<div><div>Microbial consortia that catalyze chain elongation processes have been enriched using different selection strategies, for which the electron donor is an essential one. Propanol is an extraordinarily promising electron donor because it can be generated from renewable resources, including lignocellulosic biomass and protein wastes. Here, propanol was proven in detail to be an efficient electron donor, enhancing the production of odd medium-chain carboxylates during chain elongation. By exploring various electron acceptors, reactor conditions, and electron donor/electron acceptor mol ratios, our study highlights that acetate is the most suitable electron acceptor for the production of both odd- and even-chain carboxylates. The optimal conditions for propanol-based chain elongation were 30 °C and pH 6, achieving 82.8 % selectivity for odd-chain carboxylates. Another critical insight from our work is that a propanol/acetate mol ratio of 1:1 can minimize the inhibitory effect of propanol and maximize the yield of medium-chain carboxylates, with the highest concentration of <em>n-</em>heptanoate reaching 124.5 mmol C/L. This was further illustrated by 16S rRNA amplicon sequencing, which elucidated that the community composition and keystone species in a propanol-based reactor closely resembled that of the ethanol one. The dominant phylum of the propanol-based reactor, Firmicutes showed a significant positive correlation with the concentrations of <em>n</em>-caproate and <em>n</em>-valerate. Additionally, the co-occurrence of <em>Clostridium sensu stricto</em> 12 and <em>Oscillibacter</em>, known as typical chain elongators, was identified within the propanol-based reactor. These findings enhance our understanding of propanol-based chain elongation, offer guiding principles for reactor microbiota assembly, and support efficient odd medium-chain carboxylate production.</div></div>","PeriodicalId":15788,"journal":{"name":"Journal of Environmental Sciences-china","volume":"156 ","pages":"Pages 849-858"},"PeriodicalIF":5.9,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Longfei Wang , Wentao Zhuo , Tao He , Zongyi Peng , You Mou , Minyue Wan , Xinnan Pan , Yi Li , Zhengjian Yang
{"title":"Insights into microbial actions on hydraulic concrete structures: Effects of ammonia and sulfate on community structure, function and biofilm morphology","authors":"Longfei Wang , Wentao Zhuo , Tao He , Zongyi Peng , You Mou , Minyue Wan , Xinnan Pan , Yi Li , Zhengjian Yang","doi":"10.1016/j.jes.2024.12.027","DOIUrl":"10.1016/j.jes.2024.12.027","url":null,"abstract":"<div><div>Microbial corrosion of hydraulic concrete structures (HCSs) has received increasing research concerns. However, knowledge on the morphology of attached biofilms, as well as the community structures and functions cultivated under variable nutrient levels is lacking. Here, biofilm colonization patterns and community structures responding to variable levels of ammonia and sulfate were explored. From field sampling, NH<sub>4</sub><sup>+</sup>-N was proven key factor governing community structure in attached biofilms, verifying the reliability of selecting target nutrient species in batch experiments. Biofilms exhibited significant compositional differences in field sampling and incubation experiments. As the nutrient increased in batch experiments, the growth of biofilms gradually slowed down and uneven distribution was detected. The proportions of proteins and β-<span>d</span>-glucose polysaccharides in biofilms experienced a decrease in response to elevated levels of nutrients. With the increased of nutrients, the mass losses of concretes exhibited an increase, reaching a highest value of 2.37 % in the presence of 20 mg/L of ammonia. Microbial communities underwent a significant transition in structure and metabolic functions to ammonia gradient. The highest activity of nitrification was observed in biofilms colonized in the presence of 20 mg/L of ammonia. While the communities and their functions remained relatively more stable responding to sulfate gradient. Our research provides novel insights into the structures of biofilms attached on HCSs and the metabolic functions in the presence of high level of nutrients, which is of significance for the operation and maintenance of hydraulic engineering structures.</div></div>","PeriodicalId":15788,"journal":{"name":"Journal of Environmental Sciences-china","volume":"157 ","pages":"Pages 430-442"},"PeriodicalIF":5.9,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144070804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tingting Lin , Siyu Chen , Yingyi Ren , Junyu Liang , Zhenghong Zuo , Zhiqiang Luo , Jian Yang , Chengyong He
{"title":"Developmental exposure to echimidine induces locomotor hyperactivity in zebrafish larvae via inhibiting acetylcholinesterase activity","authors":"Tingting Lin , Siyu Chen , Yingyi Ren , Junyu Liang , Zhenghong Zuo , Zhiqiang Luo , Jian Yang , Chengyong He","doi":"10.1016/j.jes.2024.12.036","DOIUrl":"10.1016/j.jes.2024.12.036","url":null,"abstract":"<div><div>Pyrrolizidine alkaloids (PAs) are natural toxins generated as secondary metabolites in plants, predominantly consisting of unsaturated PAs with diverse toxicities, such as hepatotoxicity. Echimidine, a prominent PA, is believed to exert various toxicological effects, including survival inhibition and induction of apoptosis of hepatocytes (<span><span>Gleńsk et al., 2022</span></span>). However, the effects of echimidine on development remain unclear. We selected three concentrations of 0.02, 0.2, and 2 mg/L to investigate the developmental toxicity of echimidine on zebrafish embryos. After a 7-day exposure, we observed hyperactivity and anxiety-like behavior in zebrafish larvae. Furthermore, we found that echimidine exposure significantly promoted embryonic motor neurodevelopment in genetically modified zebrafish. Next, we detected that echimidine exposure significantly increased the content of the excitatory neurotransmitter acetylcholine (ACh), accompanied by a significant decrease in acetylcholinesterase (AChE) activity. Conversely, echimidine led to a significant reduction in the content of the sedative neurotransmitter γ-aminobutyric acid (GABA), accompanied by abnormal gene expression of enzymes related to GABA synthesis. Moreover, we elucidated the strong direct binding of echimidine to zebrafish and human AChE protein through molecular docking. In summary, our study found that echimidine induced ACh accumulation possibly by inhibiting AChE activity, leading to motor neurodevelopmental abnormalities and hyperactivity in zebrafish larvae. This work provides important scientific knowledge on the effects and mechanisms of PAs on neural development, which is helpful for controlling the risk of PAs in food and protecting public health.</div></div>","PeriodicalId":15788,"journal":{"name":"Journal of Environmental Sciences-china","volume":"156 ","pages":"Pages 882-893"},"PeriodicalIF":5.9,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chunyan Xiao , Pengbo Li , Xiaoshu Chen , Tongqian Zhao , Xiaoming Guo , Yuxiao He , Guizhen Wang
{"title":"Water-soluble organic nitrogen in PM2.5 around the Danjiangkou Reservoir: Concentration, sources, and transport pathways","authors":"Chunyan Xiao , Pengbo Li , Xiaoshu Chen , Tongqian Zhao , Xiaoming Guo , Yuxiao He , Guizhen Wang","doi":"10.1016/j.jes.2024.12.030","DOIUrl":"10.1016/j.jes.2024.12.030","url":null,"abstract":"<div><div>Water-soluble organic nitrogen (WSON) affects the formation, hygroscopicity, acidity of organic aerosols, and nitrogen biogeochemical cycles. However, qualitative and quantitative characterizations of WSON remain limited due to its chemical complexity. In the study, 1-year field samples of particulate matter 2.5 (PM<sub>2.5</sub>) were collected from June 2022 to May 2023 to analyze the WSON concentration in PM<sub>2.5</sub>, and correlation analysis, positive matrix factor (PMF), and potential source contribution function (PSCF) models were employed to elucidate WSON source apportionment and transport pathways. The results revealed that the mean WSON concentrations reached 1.98 ± 2.64 µg/m³ with a mean WSON to water-soluble total nitrogen (WSTN) ratio of 21 %. Further, WSON concentration exhibited a seasonal variation trend, with higher values in winter and lower in summer. Five sources were identified as contributors to WSON in PM<sub>2.5</sub> within the reservoir area through a comprehensive analysis including correlation analysis, PSCF and concentration weighted trajectory (CWT), and PMF analyses. These sources were agricultural, dust, combustion, traffic, and industrial sources, of which agricultural source emerged as the primary contributor (76.69 %). The atmosphere in the reservoir area were primarily influenced by the transport of northeastern air masses, local agricultural activities, industrial cities along the trajectory, and coastal regions, exerting significant influences on the concentration of WSON in the reservoir area. The findings of this study addressed the research gap concerning organic nitrogen in PM<sub>2.5</sub> within the reservoir area, thereby offering a theoretical foundation and data support in controlling nitrogen pollution in the Danjiangkou Reservoir area.</div></div>","PeriodicalId":15788,"journal":{"name":"Journal of Environmental Sciences-china","volume":"156 ","pages":"Pages 757-770"},"PeriodicalIF":5.9,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jingjing Lyu , Rui Tian , Runhua Zhang , Peng Chen , Xinxin Jing , Runqin Zhang , Kang Zhao , Yi Liu , Chenhao Lyu , Zhiguo Li
{"title":"Millimeter-scale interactions of nitrogen and potassium on denitrification, anammox, and Feammox in soil fertilization zones","authors":"Jingjing Lyu , Rui Tian , Runhua Zhang , Peng Chen , Xinxin Jing , Runqin Zhang , Kang Zhao , Yi Liu , Chenhao Lyu , Zhiguo Li","doi":"10.1016/j.jes.2024.12.028","DOIUrl":"10.1016/j.jes.2024.12.028","url":null,"abstract":"<div><div>Soil denitrification, anammox, and Feammox are key for nitrogen (N) removal in agriculture. Despite potassium (K) fertilizer enhancing N efficiency, their role in regulation of these processes is unclear. A soil column incubation with <sup>15</sup>N isotope tracing was conducted to explore millimeter-scale interactions of N and K on these pathways in soil fertilization zones. After 28 days, individual applications of N and K reduced denitrification-nitrogen removal rate (DNRR), anammox-nitrogen removal rate (ANRR), and feammox-nitrogen removal rate (FNRR) compared to a non-fertilizer control. N fertilizer had a greater effect than K, likely due to the high consumption of dissolved organic carbon by N fertilizer or the increased soil organic matter decomposition by K fertilizer. Combing of N and K increased DNRR, ANRR and FNRR rates by 31 %, 3090 % and 244 % compared to single N, and by and by -53.7 %, 885 % and 222 % compared to single K. These effects diminished with depth and distance from fertilizer sites. The effects of N fertilizer on theses N removal process might be regulate abundance of key microbes (e.g., <em>Limnobacter and Clostridium</em>) and key gene (<em>nirK, hzsB, ACM</em> and <em>Geo</em>) by providing N substrates, while K enhances N metabolism efficiency through enzyme activation, indicated by the downregulation of certain genes (<em>hzsB, ACM</em> and <em>Geo</em>) and a negative correlation with N removal by simultaneously increasing gene expression and enzyme activity. These findings provide insights how N and K together enhance N removal, emphasizing their importance for optimizing this process.</div></div>","PeriodicalId":15788,"journal":{"name":"Journal of Environmental Sciences-china","volume":"157 ","pages":""},"PeriodicalIF":5.9,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hongbin Lu , Shaoyong Lu , Zequan Zeng , Zhanggen Huang , Fanhao Song
{"title":"Distinct performance and mechanism of microbial fuel cells-constructed wetland and direct-enchanced constructed wetland for levofloxacin removal","authors":"Hongbin Lu , Shaoyong Lu , Zequan Zeng , Zhanggen Huang , Fanhao Song","doi":"10.1016/j.jes.2024.12.020","DOIUrl":"10.1016/j.jes.2024.12.020","url":null,"abstract":"<div><div>There is an urgent need to investigate the distinct performance and mechanism of traditional constructed wetland (CW), microbial fuel cells-constructed wetland (MFC-CW) and direct-enchanced constructed wetland (EC<img>CW) for antibiotics removal. To address this issues, three kinds of CWs were bulit and distinct performance and mechanism for levofloxacin (LVFX) removal was expored in this study. MFC<img>CW, EC<img>CW achieved high LVFX removal efficiencies compared with traditional constructed wetland (96.0 % in MFC<img>CW, 95.0 % in EC<img>CW and 91.2 % in CW) and the biodegradation was the key contributor (90.7 %-95.3 %). MFC<img>CW is better capable to stimulate microbial activity and strengthen the removal effect of LVFX. MFC<img>CW performed well in reducing the effluent's ecotoxicity (dehydrogenase activity) and antibiotic resistance genes (ARGs). ARGs were mainly distributed in the anode region of MFC<img>CW while accumulating in the cathode region of EC<img>CW. Atribacteria, Chlorobi, Synergistetes and Firmicutes significicant effect on the efficiencies of TN, NH<sub>4</sub><sup>+</sup>, and LVFX. The core node for microbial community interaction in CW was only <em>Pseudomonas</em> in Proteobacteria (OTU4537). While MFC<img>CW included <em>Opitutae_vadinHA64</em> (OTU3153) in Verrucomicrobia, <em>Desulfomicrobium</em> (OTU3629) in Proteobacteria, and <em>Actinobacteria Gaiellales</em> (OTU4206), and EC<img>CW included <em>Mesotoga</em> (OTU1104) in Thermotogae, <em>Syntrophus</em> (OTU3207) in Proteobacteria and <em>Emticicia</em> (OTU3788) in Bacteroidetes. MFC<img>CW and EC<img>CW increased the abundance of critical microbial communities, and the microbial communities were more closely related. This study improved the understanding of the molecular mechanisms underlying the enhancement of CW by the two bioelectrochemical methods.</div></div>","PeriodicalId":15788,"journal":{"name":"Journal of Environmental Sciences-china","volume":"158 ","pages":"Pages 265-280"},"PeriodicalIF":5.9,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144320857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li-Zhi Huang , Jingjing Lin , Weiguo Chen , Wei Wang , Yitao Dai , Ivan P. Pozdnyakov , Bingbing Hu
{"title":"Generation of carbon dioxide anion radical by UV/small molecular monocarboxylic acid system for reductive dechlorination of chlorinated alkanes","authors":"Li-Zhi Huang , Jingjing Lin , Weiguo Chen , Wei Wang , Yitao Dai , Ivan P. Pozdnyakov , Bingbing Hu","doi":"10.1016/j.jes.2024.12.025","DOIUrl":"10.1016/j.jes.2024.12.025","url":null,"abstract":"<div><div>The persistence of chlorinated alkanes in aquatic environments poses significant health risks due to its biotoxicity and high volatility, which contributes to both water and air pollution. This study investigates the efficacy of carbon dioxide radical anion (CO<sub>2</sub>•<sup>−</sup>) mediated advanced reduction processes (ARPs) for the reductive dechlorination of chlorinated alkanes using small molecular monocarboxylic acids (SMAs) under UV irradiation. The study focused on formic acid (HCOOH), acetic acid (CH<sub>3</sub>COOH), and propionic acid (CH<sub>3</sub>CH<sub>2</sub>COOH) to generate CO<sub>2</sub>•<sup>−</sup>, revealing that UV/HCOOH system exhibits a notably high chloroform (CF) degradation efficiency of 97.8 % in 90 min. Kinetic studies indicated a linear relationship between the HCOOH concentrations and the observed reaction rate constants (<em>k</em><sub>obs</sub>), demonstrating that CO<sub>2</sub>•<sup>−</sup> production is crucial for CF degradation. Electron paramagnetic resonance spectroscopy identified CO<sub>2</sub>•<sup>−</sup> and hydroxyl radicals (HO•) as the active species, with the former playing a predominant role in CF degradation. The study also explored the influence of carbon chain length in SMAs on CF degradation, finding that longer chains decrease the degradation efficiency, potentially due to reduced UV activation. A higher reaction rate constant (<em>k</em><sub>obs</sub>) under acidic conditions, with a marked decrease in efficiency as the pH exceeds 3.7, where HCOO<sup>−</sup> becomes predominant. This study enhances our understanding of CO<sub>2</sub>•<sup>−</sup> mediated ARPs and explores potential applications in environmental remediation, providing insights into the pathways and mechanisms of CF degradation. The UV/SMAs systems offer advantages for practical applications, such as milder reaction conditions and higher efficiency compared to traditional methods.</div></div>","PeriodicalId":15788,"journal":{"name":"Journal of Environmental Sciences-china","volume":"158 ","pages":"Pages 50-59"},"PeriodicalIF":5.9,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144223203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yanyan Ge, Zhenyu Wen, Xuan Liu, Zhihui Xiong, Xiafang Sheng
{"title":"Sodium alginate-synthesizing regulatory gene algB in Pseudomonas putida XMS-1 decreases Cd uptake in Allium tuberosum in the Cd-polluted soil","authors":"Yanyan Ge, Zhenyu Wen, Xuan Liu, Zhihui Xiong, Xiafang Sheng","doi":"10.1016/j.jes.2024.12.023","DOIUrl":"10.1016/j.jes.2024.12.023","url":null,"abstract":"<div><div>The Cd-tolerant and sodium alginate (SA)-synthesizing <em>Pseudomonas putida</em> XMS-1 was characterized for Cd immobilization in solution. Additionally, the XMS-1 mutant constructed by deleting SA-synthesizing regulatory gene <em>algB</em> (∆<em>algB</em>) were characterized for their roles in Cd uptake in Chinese chive in the Cd-contaminated soil. Between 12 and 48 h of incubation, the XMS-1∆<em>algB</em> mutant significantly reduced solution Cd concentrations by 81 % compared with the control but increased the Cd concentrations by 36 % compared with XMS-1. After 48 h of incubation, the XMS-1∆<em>algB</em> mutant significantly increased the Cd concentration by 36 % and decreased the expolysaccharide (EPS) and SA concentrations by 30 %-32 % and cell surface-adsorbed Cd content by 24 % in the Cd-containing medium, compared with XMS-1. The XMS-1∆<em>algB</em> mutant significantly increased the root and leaf Cd contents of Chinese chive by 15 %-50 % and exchangeable Cd content by 17 % and decreased the Fe-Mn oxide- and organic matter-bound Cd contents by 17 %-23 %, compared with XMS-1. Furthermore, the XMS-1∆<em>algB</em> mutant significantly decreased the EPS content by 33 %, copies of <em>algD</em> gene involved in EPS production by 7.7-fold, and the interactions between the amino, hydroxyl, and carbonyl groups and Cd in the Cd-contaminated soil, compared with XMS-1. These results suggested that <em>algB</em> promoted XMS-1-mediated Cd-stabilizing related gene abundance and interactions between soil and Cd and decreased Cd uptake in Chinese chive. These findings may provide an effective and eco-friendly way using SA-producing bacteria for safe production of vegetables in the Cd-polluted soil.</div></div>","PeriodicalId":15788,"journal":{"name":"Journal of Environmental Sciences-china","volume":"157 ","pages":"Pages 52-64"},"PeriodicalIF":5.9,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zihan Zhao , Yan Chen , Chun Ye , Jing Wu , Zucong Cai , Yanhua Wang
{"title":"Linkage between nitrogen loss, river transport, lake accumulation and water quality properties in plain river network basin","authors":"Zihan Zhao , Yan Chen , Chun Ye , Jing Wu , Zucong Cai , Yanhua Wang","doi":"10.1016/j.jes.2024.12.022","DOIUrl":"10.1016/j.jes.2024.12.022","url":null,"abstract":"<div><div>Various forms of nitrogen (N) discharged by high-intensity human activities in the Yangtze River Delta are transported into the lake along the river channel, accelerating the lake's N cycle and increasing the eutrophication ecological risk. Taihu Lake is a typical eutrophic shallow lake, suffering from cyanobacteria blooms for decades due to excessive exogenous nutrient load. In this study, the coupling relationship between basin N loss and lake response was established by combining N flow and exogenous nutrient load. The results showed striking spatiotemporal differences and the large tributaries input the majority of N. Three evolution stages of the lake ecosystem were classified, i.e., Stage A (1980–1997) with slow increasing N load; Stage B (1998–2006) with high-level N load despite some controlling methods; Stage C (2007 to present) with the strengthening of N management in lake basin after the Water Crisis, the N load has gradually decreased, while the water flow is increasing by the year. Environmental N export in the basin was 581.46 kg/ha N in 2021, and a total of 32.06 Gg N was finally drawn into the lake. Over the recent two decades, the noticeable expansion of built-up land from 8.21 % to 21.04 % associated with its environmental impacts i.e., urban heat island effect, hard pavement, and ecological fragility deserves attention. Accordingly, the rapid climate change of the basin became the key factor driving the tributaries' hydrologic conditions (<em>r</em><sub>∂</sub> = 0.945). The developed social economy dominated the sewage discharge (<em>r</em><sub>∂</sub> = 0.857). The N inputs and losses to the environment in the basin can be further exacerbated without control. Meanwhile, the lake would respond to the exogenous input. In addition to the self-cleaning part of the lake, the N accumulation rate of the surface sediment ranged from 3.29 to 10.77 g N/(m<sup>2</sup>·yr) of Taihu Lake. To meet the pollutant control target, around 66.28 Gg anthropogenic N needs to be reduced in the upper stream area yearly. Clarifying the N flow and its environmental burden can mitigate its damage to the ecosystem and take on the refined management on the watershed scale.</div></div>","PeriodicalId":15788,"journal":{"name":"Journal of Environmental Sciences-china","volume":"157 ","pages":"Pages 65-76"},"PeriodicalIF":5.9,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}