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Xu RK, Nkoh JN. Differential immobilization of cadmium and changes in soil surface charge in acidic Ultisol by chitosan and citric acid: effect of their functional groups. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2024; 46:275. [PMID: 38958819 DOI: 10.1007/s10653-024-02051-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 05/22/2024] [Indexed: 07/04/2024]
Abstract
Soil organic matter plays an important role in cadmium adsorption and immobilization. Since different organic matter components affect cadmium adsorption processes differently, selecting the right organic substrate and knowing how to apply it could improve cadmium remediation. This study compares the effects of two contrasting organic molecules; chitosan and citric acid, on cadmium adsorption and speciation in acidic Ultisol. The adsorption of chitosan to Ultisol significantly increased the soil positive charge while adsorption of citric acid increased the soil negative charge. At pH 5.0, the maximum amount of cadmium adsorbed in excess chitosan was 341% greater than that in excess citric acid. About 73-89% and 60-62% of adsorbed cadmium were bound to Fe/Mn oxides and organic matter/sulfide at pH 4.0 while this fraction was 77-100% and 57-58% for citric acid and chitosan at pH 5.0, respectively. This decrease in the complexing ability of chitosan was related to the destabilizing effect of high pH on chitosan's structure. Also, the sequence through which chitosan, citric acid, and cadmium were added into the adsorption system influenced the adsorption profile and this was different along a pH gradient. Specifically, adding chitosan and cadmium together increased adsorption compared to when chitosan was pre-adsorbed within pH 3.0-6.5. However, for citric acid, the addition sequence had no significant effect on cadmium adsorption between pH 3.0-4.0 compared to pH 6.5 and 7.5, with excess citric acid generally inhibiting adsorption. Given that the action of citric acid is short-lived in soil, chitosan could be a good soil amendment material for immobilizing cadmium.
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Affiliation(s)
- Ren-Kou Xu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China
| | - Jackson Nkoh Nkoh
- Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China.
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China.
- Department of Chemistry, University of Buea, P.O. Box 63, Buea, Cameroon.
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Shang C, Chen J, Nkoh JN, Wang J, Chen S, Hu Z, Hussain Q. Biochemical and multi-omics analyses of response mechanisms of rhizobacteria to long-term copper and salt stress: Effect on soil physicochemical properties and growth of Avicennia marina. JOURNAL OF HAZARDOUS MATERIALS 2024; 466:133601. [PMID: 38309159 DOI: 10.1016/j.jhazmat.2024.133601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 01/18/2024] [Accepted: 01/21/2024] [Indexed: 02/05/2024]
Abstract
Mangroves are of important economic and environmental value and research suggests that their carbon sequestration and climate change mitigation potential is significantly larger than other forests. However, increasing salinity and heavy metal pollution significantly affect mangrove ecosystem function and productivity. This study investigates the tolerance mechanisms of rhizobacteria in the rhizosphere of Avicennia marina under salinity and copper (Cu) stress during a 4-y stress period. The results exhibited significant differences in antioxidant levels, transcripts, and secondary metabolites. Under salt stress, the differentially expressed metabolites consisted of 30% organic acids, 26.78% nucleotides, 16.67% organic heterocyclic compounds, and 10% organic oxides as opposed to 27.27% organic acids, 24.24% nucleotides, 15.15% organic heterocyclic compounds, and 12.12% phenyl propane and polyketides under Cu stress. This resulted in differential regulation of metabolic pathways, with phenylpropanoid biosynthesis being unique to Cu stress and alanine/aspartate/glutamate metabolism and α-linolenic acid metabolism being unique to salt stress. The regulation of metabolic pathways enhanced antioxidant defenses, nutrient recycling, accumulation of osmoprotectants, stability of plasma membrane, and chelation of Cu, thereby improving the stress tolerance of rhizobacteria and A. marina. Even though the abundance and community structure of rhizobacteria were significantly changed, all the samples were dominated by Proteobacteria, Chloroflexi, Actinobacteriota, and Firmicutes. Since the response mechanisms were unbalanced between treatments, this led to differential growth trends for A. marina. Our study provides valuable inside on variations in diversity and composition of bacterial community structure from mangrove rhizosphere subjected to long-term salt and Cu stress. It also clarifies rhizobacterial adaptive mechanisms to these stresses and how they are important for mitigating abiotic stress and promoting plant growth. Therefore, this study can serve as a reference for future research aimed at developing long-term management practices for mangrove forests.
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Affiliation(s)
- Chenjing Shang
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Shenzhen Public Service Platform for Collaborative Innovation of Marine Algae Industry, Guangdong Engineering Research Center for Marine Algal Biotechnology, College of Life Science and Oceanography, Shenzhen University, Shenzhen 518060, PR China; Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, PR China
| | - Jiawen Chen
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Shenzhen Public Service Platform for Collaborative Innovation of Marine Algae Industry, Guangdong Engineering Research Center for Marine Algal Biotechnology, College of Life Science and Oceanography, Shenzhen University, Shenzhen 518060, PR China
| | - Jackson Nkoh Nkoh
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Shenzhen Public Service Platform for Collaborative Innovation of Marine Algae Industry, Guangdong Engineering Research Center for Marine Algal Biotechnology, College of Life Science and Oceanography, Shenzhen University, Shenzhen 518060, PR China; College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, PR China; Department of Chemistry, University of Buea, P.O. Box 63, Buea, Cameroon.
| | - Junjie Wang
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Shenzhen Public Service Platform for Collaborative Innovation of Marine Algae Industry, Guangdong Engineering Research Center for Marine Algal Biotechnology, College of Life Science and Oceanography, Shenzhen University, Shenzhen 518060, PR China
| | - Si Chen
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Shenzhen Public Service Platform for Collaborative Innovation of Marine Algae Industry, Guangdong Engineering Research Center for Marine Algal Biotechnology, College of Life Science and Oceanography, Shenzhen University, Shenzhen 518060, PR China
| | - Zhangli Hu
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Shenzhen Public Service Platform for Collaborative Innovation of Marine Algae Industry, Guangdong Engineering Research Center for Marine Algal Biotechnology, College of Life Science and Oceanography, Shenzhen University, Shenzhen 518060, PR China
| | - Quaid Hussain
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Shenzhen Public Service Platform for Collaborative Innovation of Marine Algae Industry, Guangdong Engineering Research Center for Marine Algal Biotechnology, College of Life Science and Oceanography, Shenzhen University, Shenzhen 518060, PR China; College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, PR China
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Nkoh JN, Shi RY, Li JY, Xu RK. Combined application of Pseudomonas fluorescens and urea can mitigate rapid acidification of cropland Ultisol. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167652. [PMID: 37813255 DOI: 10.1016/j.scitotenv.2023.167652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/03/2023] [Accepted: 10/05/2023] [Indexed: 10/11/2023]
Abstract
Rhizobacteria maintain a healthy soil required for crop growth. This has led to increased interest in the use of bacteria-based biofertilizers in agriculture as they improve soil nutrient content and protect plants against pathogens. However, the effect of bacteria inoculum on N transformation and soil physicochemical properties during urea fertilization remains unexploited. Thus, this study investigated the effect of Pseudomonas fluorescens on urea N transformation in an acidic Ultisol within a 70-d incubation period. The results revealed that (1) soil pH peaked on d 5 (pH 5.58) and 20 (pH 6.23) and rapidly decreased till d 62 (pH 4.10) and 50 (pH 4.93) for urea and urea + bacteria treatments, respectively, and remained constant thereafter. After 70 d, the pH of the bacteria-treated Ultisol remained higher (0.78 pH units) than that of urea-treated Ultisol; (2) the change in soil pH was in agreement with the mineralization trend of N, as the concentration of NH4+-N peaked on d 5 (134.2 mg N kg-1) and 20 (423 mg N kg-1) before decreasing to 62.1 and 276.1 mg N kg-1 on d 70 in urea-treated and bacteria-treated Ultisol, respectively; and (3) P. fluorescens consumed protons produced during nitrification to retard rapid decrease in soil pH, decreased soil exchangeable acidity (33.3 %), increased soil effective cation exchange capacity (32.8 %), and increased the solubility of soil exchangeable base cations (68.4 %, Ca2+ + Mg2+ + K+ + Na+). Thus, bacterial inoculum could promote N mineralization, enhance nutrient solubility, and retard soil acidification during N transformation in soils.
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Affiliation(s)
- Jackson Nkoh Nkoh
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China; College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China; Department of Chemistry, University of Buea, P.O. Box 63, Buea, Cameroon.
| | - Ren-Yong Shi
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China.
| | - Jiu-Yu Li
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China.
| | - Ren-Kou Xu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China.
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Zhang L, Hu Y, Chen Y, Qi D, Cai B, Zhao Y, Li Z, Wang Y, Nie Z, Xie J, Wang W. Cadmium-tolerant Bacillus cereus 2-7 alleviates the phytotoxicity of cadmium exposure in banana plantlets. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166645. [PMID: 37657542 DOI: 10.1016/j.scitotenv.2023.166645] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 08/05/2023] [Accepted: 08/26/2023] [Indexed: 09/03/2023]
Abstract
Bananas are the world's important fruit and staple crop in the developing countries. Cadmium (Cd) contamination in soils results in the decrease of crop yield and food safety. Bioremediation is an environmental-friendly and effective measure using Cd-tolerant plant growth promoting rhizobacteria (PGPR). In our study, a Cd-resistant PGPR Bacillus cereus 2-7 was isolated and identified from a discarded gold mine. It could produce multiple plant growth promoting biomolecules such as siderophores, indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylate (ACC)-deaminase and phosphatase. The extracellular accumulation was a main manner of Cd removal. Surplus Cd induced the expression of Cd resistance/transport genes of B. cereus 2-7 to maintain the intracellular Cd homeostasis. The pot experiment showed that Cd contents decreased by 50.31 % in soil, 45.43 % in roots, 56.42 % in stems and 79.69 % in leaves after the strain 2-7 inoculation for 40 d. Bacterial inoculation alleviated the Cd-induced oxidative stress to banana plantlets, supporting by the increase of chlorophyll contents, plant height and total protein contents. The Cd remediation mechanism revealed that B. cereus 2-7 could remodel the rhizosphere bacterial community structure and improve soil enzyme activities to enhance the immobilization of Cd. Our study provides a Cd-bioremediation strategy using Cd-resistant PGPR in tropical and subtropical area.
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Affiliation(s)
- Lu Zhang
- National Key Laboratory of Tropical Crop Breeding, Hainan Institute for Tropical Agricultural Resources, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, China; Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158, China
| | - Yulin Hu
- South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, Guangzhou 524091, China
| | - Yufeng Chen
- National Key Laboratory of Tropical Crop Breeding, Hainan Institute for Tropical Agricultural Resources, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, China
| | - Dengfeng Qi
- National Key Laboratory of Tropical Crop Breeding, Hainan Institute for Tropical Agricultural Resources, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, China
| | - Bingyu Cai
- National Key Laboratory of Tropical Crop Breeding, Hainan Institute for Tropical Agricultural Resources, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, China
| | - Yankun Zhao
- National Key Laboratory of Tropical Crop Breeding, Hainan Institute for Tropical Agricultural Resources, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, China
| | - Zhuoyang Li
- National Key Laboratory of Tropical Crop Breeding, Hainan Institute for Tropical Agricultural Resources, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, China
| | - Yong Wang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158, China
| | - Zongyu Nie
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158, China
| | - Jianghui Xie
- National Key Laboratory of Tropical Crop Breeding, Hainan Institute for Tropical Agricultural Resources, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, China
| | - Wei Wang
- National Key Laboratory of Tropical Crop Breeding, Hainan Institute for Tropical Agricultural Resources, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, China.
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Wu JY, Hua ZL, Gu L. Iron-Nitrogen Amendment Reduced Perfluoroalkyl Acids' Phyto-Uptake in the Wheat-Soil Ecosystem: Contributions of Dissolved Organic Matters in Soil Solution and Root Extracellular Polymeric Substances. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:16065-16074. [PMID: 37843047 DOI: 10.1021/acs.est.3c04788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Understanding the mechanisms underlying perfluoroalkyl acids (PFAAs) translocation, distribution, and accumulation in wheat-soil ecosystems is essential for agricultural soil pollution control and crop ecological risk assessment. This study systematically investigated the translocation of 13 PFAAs under different iron and nitrogen fertilization conditions in a wheat-soil ecosystem. Short-chain PFAAs including PFBA, PFPeA, PFHxA, and PFBS mostly accumulated in soil solution (10.43-55.33%) and soluble extracellular polymeric substances (S-EPS) (11.39-14.77%) by the adsorption to amino- (-NH2) and hydroxyl (-OH) groups in dissolved organic matter (DOM). Other PFAAs with longer carbon chain lengths were mostly distributed on the soil particle surface by hydrophobic actions (74.63-94.24%). Iron-nitrogen amendments triggered (p < 0.05) soil iron-nitrogen cycling, rhizospheric reactive oxygen species fluctuations, and the concentration increases of -NH2 and -OH in the DOM structure. Thus, the accumulation capacity of PFAAs in soil solution and root EPS was increased. In sum, PFAAs' translocation from soil particles to wheat root was synergistically reduced by iron and nitrogen fertilization through increased adsorption of soil particles (p < 0.05) and the retention of soil solution and root EPSs. This study highlights the potential of iron-nitrogen amendments in decreasing the crop ecological risks to PFAAs' pollution.
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Affiliation(s)
- Jian-Yi Wu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
- Yangtze Institute for Conservation and Development, Hohai University, Nanjing, Jiangsu 210098, China
| | - Zu-Lin Hua
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
- Yangtze Institute for Conservation and Development, Hohai University, Nanjing, Jiangsu 210098, China
| | - Li Gu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
- Yangtze Institute for Conservation and Development, Hohai University, Nanjing, Jiangsu 210098, China
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Wu J, Song Q, Wu Y, Liu J, Wu Z, Zhou J, Wang Y, Wu W. Application of phosphorus amendments reduces metal uptake and increases yield of Oryza saliva L. (rice) in Cd/Cu-contaminated paddy field. CHEMOSPHERE 2023; 318:137875. [PMID: 36646182 DOI: 10.1016/j.chemosphere.2023.137875] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 12/30/2022] [Accepted: 01/12/2023] [Indexed: 06/17/2023]
Abstract
To alleviate worldwide food safety issues caused by metal contamination, an easily available material is urgently needed for extensive application. In this study, calcium magnesium phosphate fertiliser (Pcm) was applied to a Cd/Cu co-contaminated paddy field in comparison with limestone and organic fertiliser. The results showed that only Pcm is effective in simultaneously reducing Cd uptake by 56.7% and Cu uptake by 36.2% in Oryza saliva L. (rice). The rice yield, reduced mainly by Cu, also increased by 30.1% with respect to the enhancement of soil pH, cation exchange capacity and availability of phosphorus, as well as the reduction in availabilities of Cd and Cu. Additionally, Pcm dramatically shaped the bacterial community structure, with Proteobacteria and Firmicutes predominant in the soils. The beneficial genera Exiguobacterium, Citrobacter, and Acinetobacter, which are vital for phosphate dissolution and Cd/Cu immobilisation, were also enriched. The results demonstrated that the application of Pcm at 0.4% (w:w) was able to enhance both crop quantity and quality in Cd/Cu co-contaminated paddy fields by reducing Cu/Cd availability, promoting rice yield, and reshaping bacterial community structures.
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Affiliation(s)
- Jiahui Wu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, 7 West Street, Yuancun, Guangzhou, 510655, PR China
| | - Qingmei Song
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, 7 West Street, Yuancun, Guangzhou, 510655, PR China
| | - Yingxin Wu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, 7 West Street, Yuancun, Guangzhou, 510655, PR China.
| | - Junjun Liu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, 7 West Street, Yuancun, Guangzhou, 510655, PR China
| | - Zhuohao Wu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, 7 West Street, Yuancun, Guangzhou, 510655, PR China
| | - Jingyan Zhou
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, 7 West Street, Yuancun, Guangzhou, 510655, PR China
| | - Yuntao Wang
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, 7 West Street, Yuancun, Guangzhou, 510655, PR China
| | - Wencheng Wu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, 7 West Street, Yuancun, Guangzhou, 510655, PR China.
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Li M, Liu D, Wang S, Guo H, Losic D, Deng L, Wu S, Yuan P. Efficient removal of Cd 2+ by diatom frustules self-modified in situ with intercellular organic components. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 319:121005. [PMID: 36608731 DOI: 10.1016/j.envpol.2023.121005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/28/2022] [Accepted: 01/02/2023] [Indexed: 06/17/2023]
Abstract
The organic modification of three-dimensional porous diatom frustules (biosilica) and their fossils (diatomite) is promising in heavy metal adsorption. However, the preparation of such materials involves complex processes, high costs, and environmental hazards. In this study, organic-biosilica composites based on in situ self-modification of diatoms were prepared by freeze-drying pretreatment. Freeze-drying resulted in the release of the intercellular organic components of diatoms, followed by loading on the surface of their diatom frustules. The bio-adsorbent exhibits outstanding Cd2+ adsorption capacity (up to 220.3 mg/g). The adsorption isotherms fitted the Langmuir model and the maximum adsorption capacity was 4 times greater than that of diatom biosilica (54.1 mg/g). The adsorption kinetics of Cd2+ was adequately described by a pseudo-second-order model and reached equilibrium within 30 min. By combining focused ion beam thinning with transmission electron microscopy-energy dispersive X-ray spectroscopy, the internal structure of the composite and the Cd2+ distribution were investigated. The results showed that the organic matter of the composite adsorbed approximately 10 times more Cd2+ than inorganic biosilica. The adsorption mechanism was dominated by complexation between the abundant organic functional groups (amide, carboxyl, and amino groups) on the surfaces of composite and Cd2+. The bio-adsorbent was demonstrated to have wide applicability in the presence of competitive cations (Na+, K+, Ca2+, and Mg2+) and under a wide range of pH (3-10) conditions. Thus, the self-modification of diatoms offers a promising organic-inorganic composite for heavy metal remediation.
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Affiliation(s)
- Mengyuan Li
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, CAS Center for Excellence in Deep Earth Science, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Dong Liu
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, CAS Center for Excellence in Deep Earth Science, Chinese Academy of Sciences, Guangzhou, 510640, China; State Key Laboratory of Marine Environmental Science (MEL), Xiamen University, Xiamen, 361012, China.
| | - Shun Wang
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, CAS Center for Excellence in Deep Earth Science, Chinese Academy of Sciences, Guangzhou, 510640, China; Neutron Science Platform, Songshan Lake Materials Laboratory, Dongguan, 523808, China
| | - Haozhe Guo
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, CAS Center for Excellence in Deep Earth Science, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Dusan Losic
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - Liangliang Deng
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, CAS Center for Excellence in Deep Earth Science, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Shijun Wu
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, CAS Center for Excellence in Deep Earth Science, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Peng Yuan
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, CAS Center for Excellence in Deep Earth Science, Chinese Academy of Sciences, Guangzhou, 510640, China; School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China
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Liu Y, Zhang B, Han YH, Yao Y, Guo P. Involvement of exogenous arsenic-reducing bacteria in root surface biofilm formation promoted phytoextraction of arsenic. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:160158. [PMID: 36379332 DOI: 10.1016/j.scitotenv.2022.160158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 11/09/2022] [Indexed: 06/16/2023]
Abstract
Root surface biofilm (RSB) is the last window for pollutants entering plant roots and thus plays a critical role in the phytoextraction of pollutants. Exogenous arsenic-reducing bacteria (EARB) have been adopted to enhance the phytoextraction of arsenic (As). However, whether EARB would be involved in RSB formation together with indigenous bacteria and the role of EARB involvement in As phytoextraction are still unknown. Herein, two EARB strains and two phytoextractors (wheat and maize) were selected to investigate the involvement of EARB in RSB formation and its role in As phytoextraction. Results showed that EARB successfully participated in RSB formation together with indigenous bacteria, attributing to their strong chemotaxis and biofilm formation abilities induced by root exudates. The involvement of EARB in RSB formation significantly enhanced As accumulation in plant roots, since more arsenite (As(III)) caused by arsenate (As(V)) reduction in RSB was absorbed by roots. Its underlying mechanism was further elucidated. EARB involvement increased phylum Proteobacteria to produce more siderophores in RSB. Siderophores then improved photosynthesis by increasing catalase and peroxidase activities and decreasing the malondialdehyde of plants. These actions further raised the shoot fresh weight to enhance As accumulation in plant roots. Moreover, mesophyll cell in wheat has a stronger As(V) reduction ability than that in maize, resulting in opposite distribution patterns of As(III) and As(V) in wheat and maize shoots. This study provides a new understanding of phytoextraction enhanced by exogenous bacteria and fills the gap in the role of EARB in As phytoextraction from the perspective of the RSB microregion.
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Affiliation(s)
- Yibo Liu
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun 130012, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130012, PR China
| | - Baiyu Zhang
- Department of Civil Engineering, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL A1B 3X5, Canada
| | - Yong-He Han
- College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, P R, China; Fujian Key Laboratory of Pollution Control and Resource Reuse, Fuzhou 350007, PR China
| | - Ye Yao
- College of Physics, Jilin university, Changchun 130012, PR China
| | - Ping Guo
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun 130012, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130012, PR China.
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Nkoh JN, Li KW, Shi YXX, Li JY, Xu RK. The mechanism for enhancing phosphate immobilization on colloids of oxisol, ultisol, hematite, and gibbsite by chitosan. CHEMOSPHERE 2022; 309:136749. [PMID: 36209864 DOI: 10.1016/j.chemosphere.2022.136749] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/26/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Phosphorus (P) availability in highly weathered soils is significantly influenced by the contents of iron (Fe)/aluminum (Al) oxides, clay minerals, and organic matter. With the increasing interest in biofertilizers (e.g. chitosan), it is important to understand how they affect P adsorption profiles on colloids of weathered soils rich in Fe/Al oxides. Thus, the effect of chitosan on the adsorption of P to colloids of hematite, gibbsite, Oxisol, and Ultisol was studied through electrokinetic measurements, spectroscopic analysis, and adsorption edge/isotherm profiles. The presence of chitosan significantly improved the surface positive charge and the decreasing trend of surface positive charge was slower for chitosan-treated colloids compared to the control with increasing pH. At pH 5.0, all the colloids were positively charged, with the oxides containing more positve charges than the soil colloids. At this pH value, the surface coverage capacity of P was 99.1, 61.6, 50.5, and 37.5 mmol kg⁻1 for Oxisol, Ultisol, hematite, and gibbsite, respectively. This suggests that clay minerals in soil colloids were vital in enhancing P adsorption. In the presence of chitosan, the surface coverage capacity of P was increased by 111%, 173%, 647%, and 488% for Oxisol, Ultisol, gibbsite, and hematite, respectively. Drawing inferences from spectroscopic analysis, citric acid desorption profile, and zeta potential analysis, we suggest that chitosan (CH) enhanced P adsorption by promoting the formation of (i) citric acid "undisplaceable" inner-sphere P complexes such as [Colloid-OP-O-CH] and [Colloid-OP-N-CH], (ii) citric acid "displaceable" outer-sphere P complexes such as {[Colloid-O-CH]-OP} and {[Colloid-N-CH]-OP}, and (iii) water "leachable or soluble" P complexes such as {[Colloid-CH]+PO4³⁻} and {[Colloid-OP]⁻CH+}. Thus, applying chitosan as a biofertilizer (source of N) along with P in highly weathered soils could improve P availability while reducing P leaching.
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Affiliation(s)
- Jackson Nkoh Nkoh
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; Department of Chemistry, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Ke-Wei Li
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yang-Xiao-Xiao Shi
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiu-Yu Li
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China
| | - Ren-Kou Xu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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10
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Tian Q, Wang J, Cui L, Zeng W, Qiu G, Hu Q, Peng A, Zhang D, Shen L. Longitudinal physiological and transcriptomic analyses reveal the short term and long term response of Synechocystis sp. PCC6803 to cadmium stress. CHEMOSPHERE 2022; 303:134727. [PMID: 35513082 DOI: 10.1016/j.chemosphere.2022.134727] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 06/14/2023]
Abstract
Due to the bioaccumulation and non-biodegradability of cadmium, Cd can pose a serious threat to ecosystem even at low concentration. Microalgae is widely distributed photosynthetic organisms in nature, which is a promising heavy metal remover and an effective industrial sewage cleaner. However, there are few detailed reports on the short-term and long-term molecular mechanisms of microalgae under Cd stress. In this study, the adsorption behavior (growth curve, Cd removal efficiency, scanning electron microscope, Fourier transform infrared spectroscopy, and dynamic change of extracellular polymeric substances), cytotoxicity (photosynthetic pigment, MDA, GSH, H2O2, O2-) and stress response mechanism of microalgae were discussed under EC50. RNA-seq detected 1413 DEGs in 4 treatment groups. These genes were related to ribosome, nitrogen metabolism, sulfur transporter, and photosynthesis, and which been proved to be Cd-responsive DEGs. WGCNA (weighted gene co-expression network analysis) revealed two main gene expression patterns, short-term stress (381 genes) and long-term stress (364 genes). The enrichment analysis of DEGs showed that the expression of genes involved in N metabolism, sulfur transporter, and aminoacyl-tRNA biosynthesis were significantly up-regulated. This provided raw material for the synthesis of the important component (cysteine) of metal chelate protein, resistant metalloprotein and transporter (ABC transporter) in the initial stage, which was also the short-term response mechanism. Cd adsorption of the first 15 min was primary dependent on membrane transporter and beforehand accumulated EPS. Simultaneously, the up-regulated glutathione S-transferase (GSTs) family proteins played a role in the initial resistance to exogenous Cd. The damaged photosynthetic system was repaired at the later stage, the expressions of glycolysis and gluconeogenesis were up-regulated, to meet the energy and substances of physiological metabolic activities. The study is the first to provide detailed short-term and long-term genomic information on microalgae responding to Cd stress. Meanwhile, the key genes in this study can be used as potential targets for algae-mediated genetic engineering.
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Affiliation(s)
- Qinghua Tian
- School of Metallurgy and Environment, Central South University, Changsha, Hunan, 410083, China
| | - Junjun Wang
- School of Metallurgy and Environment, Central South University, Changsha, Hunan, 410083, China
| | - Linlin Cui
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China
| | - Guanzhou Qiu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China
| | - Qi Hu
- Department of Bioinformatics Center, NEOMICS Institute, Shenzhen, Guangdong, 518118, China
| | - Anan Peng
- School of Environmental and Chemical Engineering, Foshan University, Foshan, 528000, China
| | - Du Zhang
- Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China.
| | - Li Shen
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China.
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11
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Wu X, Gao B, Lyu X, Zeng X, Wu J, Sun Y. Insight into the mechanism of phosphate and cadmium co-transport in natural soils. JOURNAL OF HAZARDOUS MATERIALS 2022; 435:129095. [PMID: 35650735 DOI: 10.1016/j.jhazmat.2022.129095] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/04/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Phosphate is ubiquitous in the environment and can affect the transport of heavy metals in the subsurface systems. In this study, column experiments were conducted to systematically evaluate the effects of phosphate on the transport of Cd in natural soils (RS, BS) under different ionic strength (IS) conditions. The presence of phosphate significantly retarded the transport of Cd in the soils. The extent of retardation was closely associated with phosphate concentrations, IS and soil properties. Increasing phosphate adsorption induced more negative surface charges on soils, thereby contributing to greater retention of Cd through electrostatic attraction. In contrast, higher IS not only promoted mobility of Cd, but also reduced the retardation effect of phosphate on Cd transport in soils. Moreover, higher Fe/Al oxides contents in RS exhibited a more pronounced effect of phosphate on Cd retardation. Our results indicated that electrostatic interaction was the predominant mechanism controlling co-transport of Cd with phosphate, but no ternary surface complexes was observed in the Cd LIII-edge XANES spectra. Our findings highlight the critical role of phosphate in retarding Cd transport in natural soils, which should be considered in assessing environmental risks of heavy metals in the subsurface.
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Affiliation(s)
- Xiaoli Wu
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Surficial Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Hydrosciences Department, Nanjing University, Nanjing 210023, China
| | - Bin Gao
- Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Xueyan Lyu
- School of Hydrology and Water Resources, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Xiankui Zeng
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Surficial Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Hydrosciences Department, Nanjing University, Nanjing 210023, China
| | - Jichun Wu
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Surficial Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Hydrosciences Department, Nanjing University, Nanjing 210023, China
| | - Yuanyuan Sun
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Surficial Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Hydrosciences Department, Nanjing University, Nanjing 210023, China.
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12
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Xiang Y, Liu G, Yin Y, Cai Y. Binding characteristics of Hg(II) with extracellular polymeric substances: implications for Hg(II) reactivity within periphyton. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:60459-60471. [PMID: 35426017 DOI: 10.1007/s11356-022-19875-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 03/19/2022] [Indexed: 06/14/2023]
Abstract
Periphyton contains extracellular polymeric substances (EPS), yet little is known about how periphyton EPS affect the speciation and mobility of mercury (Hg(II)) in aquatic systems. This study extracted and characterized EPS from periphyton in Florida Everglades, and explored its role in Hg(II) binding and speciation using multiple approaches. Results from Fourier transform infrared spectroscopy (FTIR) revealed that colloidal and capsular EPS were primarily comprised of proteins, polysaccharides, phospholipids, and nucleic acids. Ultrafiltration experiments demonstrated that 77 ± 7.7% and 65 ± 5.5% of Hg(II) in EPS solution could be transformed into colloidal and capsular EPS-bound forms. Three-dimensional excitation emission fluorescence spectra (3D-EEMs) showed that the binding constants (Kb) between colloidal/capsular EPS and Hg(II) were 3.47×103 and 2.62×103 L·mol-1. Together with 3D-EEMs and FTIR, it was found that the protein-like and polysaccharide-like substances in EPS contributed to Hg(II) binding. For colloidal EPS, COO- was the most preferred Hg(II) binding group, while C-N, C-O-C, and C-OH were the most preferred ones in capsular EPS. Using the stannous-reducible Hg approach, it was found that EPS significantly decreased the reactive Hg(II). Overall, this study demonstrated that EPS from periphyton are important organic ligands for Hg(II) complexation, which may further affect the migration and reactivity of Hg(II) in aquatic environment. These observations could improve our understanding of Hg(II) methylation and accumulation within periphyton in aquatic systems.
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Affiliation(s)
- Yuping Xiang
- Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- Department of Chemistry & Biochemistry and Southeast Environmental Research Center, Florida International University, 11200 SW 8th ST, Miami, FL, 33199, USA
| | - Guangliang Liu
- Department of Chemistry & Biochemistry and Southeast Environmental Research Center, Florida International University, 11200 SW 8th ST, Miami, FL, 33199, USA
| | - Yongguang Yin
- Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yong Cai
- Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
- Department of Chemistry & Biochemistry and Southeast Environmental Research Center, Florida International University, 11200 SW 8th ST, Miami, FL, 33199, USA.
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
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13
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An H, Tian T, Wang Z, Jin R, Zhou J. Role of extracellular polymeric substances in the immobilization of hexavalent chromium by Shewanella putrefaciens CN32 unsaturated biofilms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 810:151184. [PMID: 34699809 DOI: 10.1016/j.scitotenv.2021.151184] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/05/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
Microbial remediation provides a promising avenue for the management and restoration of heavy metal-contaminated soils. Microorganisms in soils usually exist within unsaturated biofilms, however, their response to heavy metals is still limited compared to saturated biofilms. This work investigated the Cr(VI) immobilization by Shewanella putrefaciens CN32 unsaturated biofilms, and explored the underlying mechanisms of Cr(VI) complexation. Results reveal a dose-dependent toxicity of Cr(VI) to the growth of the unsaturated biofilms. During the early growth stage, the Cr(VI) addition stimulated more extracellular polymeric substances (EPS) production. In the meantime, the EPS were demonstrated to be the primary components for Cr(VI) immobilization, which accounted for more than 60% of the total adsorbed Cr(VI). The Fourier transform infrared spectra and X-ray photoelectron spectra corroborated that the binding sites for immobilizing Cr(VI) were hydroxyl, carboxyl, phosphoryl and amino functional groups of the proteins and polysaccharides in EPS. However, for the starved unsaturated biofilms, EPS were depleted and the EPS-bound Cr(VI) were released, which caused approximately 60% of the adsorbed Cr(VI) onto cell components and further aggravated the Cr(VI) stress to cells. This work extends our understanding about the Cr(VI) immobilization by unsaturated biofilms, and provides useful information for remediation of heavy metal-contaminated soils.
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Affiliation(s)
- Hui An
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environment Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Tian Tian
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environment Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Ziting Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environment Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Ruofei Jin
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environment Science and Technology, Dalian University of Technology, Dalian 116024, China.
| | - Jiti Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environment Science and Technology, Dalian University of Technology, Dalian 116024, China
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Metal Complexes—A Promising Approach to Target Biofilm Associated Infections. Molecules 2022; 27:molecules27030758. [PMID: 35164021 PMCID: PMC8838073 DOI: 10.3390/molecules27030758] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/19/2022] [Accepted: 01/23/2022] [Indexed: 02/06/2023] Open
Abstract
Microbial biofilms are represented by sessile microbial communities with modified gene expression and phenotype, adhered to a surface and embedded in a matrix of self-produced extracellular polymeric substances (EPS). Microbial biofilms can develop on both prosthetic devices and tissues, generating chronic and persistent infections that cannot be eradicated with classical organic-based antimicrobials, because of their increased tolerance to antimicrobials and the host immune system. Several complexes based mostly on 3D ions have shown promising potential for fighting biofilm-associated infections, due to their large spectrum antimicrobial and anti-biofilm activity. The literature usually reports species containing Mn(II), Ni(II), Co(II), Cu(II) or Zn(II) and a large variety of multidentate ligands with chelating properties such as antibiotics, Schiff bases, biguanides, N-based macrocyclic and fused rings derivatives. This review presents the progress in the development of such species and their anti-biofilm activity, as well as the contribution of biomaterials science to incorporate these complexes in composite platforms for reducing the negative impact of medical biofilms.
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15
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Tan Z, Abdoulahi MH, Yang X, Zhu Y, Gong B, Li Y. Carbon source type can affect tetracycline removal by Pseudomonas sp. TC952 through regulation of extracellular polymeric substances composition and production. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 804:149907. [PMID: 34517307 DOI: 10.1016/j.scitotenv.2021.149907] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/17/2021] [Accepted: 08/22/2021] [Indexed: 06/13/2023]
Abstract
The objective of this work is to elucidate the mechanism of tetracycline (TC) removal by Pseudomonas sp. TC952. The TC removal characteristics of strain TC952 under various environmental conditions were studied. Results showed that the bio-removal efficiency was significantly affected by initial TC and peptone concentration, pH values, divalent metal ion (Zn2+) and carbon source, and the strain TC952 efficiently removed approximately 72.8% of TC within 6 days with 10 g/L peptone. The best conditions for strain TC952 to remove TC are as follows: initial TC concentration is 50 mg/L, solution initial pH is 7, Zn2+ concentration is 0.1 μg/L, carbon source is peptone. And through intra- and extracellular fractions assay and extracellular polymeric substances (EPS) component analysis, TC removal by strain TC952 was mainly attributed to the adsorption by bacterial EPS and bacterial cell. Furthermore, different carbon source affected the EPS production content and component of strain TC952, so EPS produced under peptone and serine conditions could bio-adsorb TC and formed a buffer area outside the cells, thus reducing or preventing TC from entering the bacteria cells. All the results obtained showed that secretion of EPS and adsorption of TC by EPS and bacterial cell wall may be a common way for bacteria to reduce TC in the environment, which brought novel insights for better management of TC contamination by functional bacteria and for understanding the natural removal process of antibiotics by microorganisms in the environment.
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Affiliation(s)
- Zewen Tan
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou 510642, PR China
| | - Maman Hassan Abdoulahi
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou 510642, PR China
| | - Xiuyue Yang
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou 510642, PR China
| | - Yanmei Zhu
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou 510642, PR China
| | - Beini Gong
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou 510642, PR China
| | - Yongtao Li
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou 510642, PR China.
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16
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Wang S, Lao W, He Y, Shi H, Ye Q, Ma J. Promoting the stability and adsorptive capacity of Fe 3O 4-embedded expanded graphite with an aminopropyltriethoxysilane-polydopamine coating for the removal of copper(ii) from water. RSC Adv 2021; 11:35673-35686. [PMID: 35493170 PMCID: PMC9043260 DOI: 10.1039/d1ra05160a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 10/22/2021] [Indexed: 01/07/2023] Open
Abstract
In this study, three magnetic graphites, namely, EGF, GAF, and GFA + KH550, were prepared, which were loaded either with Fe3O4 or with Fe3O4 and PDA or with Fe3O4, PDA, and KH550 onto expanded graphite. ATR-FTIR, XRD, XPS, SEM, TEM, and TGA characterization results showed that EGF, GAF, and GFA + KH550 were successfully prepared. Under the same initial copper concentration, the removal rates of copper ions by EGF, GFA, and GFA + KH550 were 86.2%, 96.9%, and 97.0%, respectively and the hazard index reductions of the three adsorbents were 2191 ± 71 (EGF), 1843 ± 68 (GFA), and 1664 ± 102 (GFA + KH550), respectively. Therefore GFA + KH550 exhibited better removal of Cu(ii) than EGF and GFA, for PDA and KH550 provided more adsorption-active sites like –OH and –NH. Here, the adsorption of GFA + KH550 fitted the pseudo-second-order kinetic and Langmuir models well within the testing range, which means that adsorption occurs on a monolayer surface between Cu(ii) and the adsorption sites. The intraparticle diffusion model and various thermodynamic parameters demonstrated that Cu(ii) was adsorbed on GFA + KH550 mainly via external surface diffusion and that the process was both endothermic and spontaneous. Recycling experiments show that GFA + KH550 has a satisfactory recyclability, and the way of direct recovery by magnets exhibits good magnetic induction. GFA + KH550 was applied in lake water and artificial seawater samples, and exhibited better removal of copper than that in DI water under the same environmental conditions for the existence of macromolecular organic matter. Furthermore, the adsorption capacity of copper ions was not relative to the salinity of water. The application of GFA + KH550 demonstrated the potential for application in water treatment procedures. In this study, three magnetic graphites, namely, EGF, GAF, and GFA + KH550, were prepared, which were loaded either with Fe3O4 or with Fe3O4 and PDA or with Fe3O4, PDA, and KH550 onto expanded graphite.![]()
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Affiliation(s)
- Shunhui Wang
- School of Chemistry and Chemical Engineering, Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University Chengdu 610500 China +86 28 83037367
| | - Wenjian Lao
- Southern California Coastal Water Research Project Authority Costa Mesa California 92626 USA
| | - Yi He
- School of Chemistry and Chemical Engineering, Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University Chengdu 610500 China +86 28 83037367.,State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu Sichuan 610500 China
| | - Heng Shi
- School of Chemistry and Chemical Engineering, Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University Chengdu 610500 China +86 28 83037367
| | - Qihang Ye
- School of Chemistry and Chemical Engineering, Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University Chengdu 610500 China +86 28 83037367
| | - Jing Ma
- School of Chemistry and Chemical Engineering, Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University Chengdu 610500 China +86 28 83037367
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Ramalingam B, Venkatachalam SS, Kiran MS, Das SK. Rationally designed Shewanella oneidensis Biofilm Toilored Graphene-Magnetite Hybrid Nanobiocomposite as Reusable Living Functional Nanomaterial for Effective Removal of Trivalent Chromium. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 278:116847. [PMID: 33799078 DOI: 10.1016/j.envpol.2021.116847] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 01/25/2021] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
Sustainable treatment of wastewater containing trivalent chromium (Cr3+) remains a significant challenge owing to the several limitations of the existing methodologies. Herein, combination of biosynthesis and Response Surface Methodology (RSM) for the fabrication and optimization of Shewanella oneidensis biofilm functionalized graphene-magnetite (GrM) nanobiocomposite was adopted as a 'living functional nanomaterial' (viz. S-GrM) for effective removal of Cr3+ ions from aqueous solution. In the biosynthetic process, S. oneidensis cells reduced the GO-akaganeite complex and adhered on the as-synthesized GrM nanocomposite to form S-GrM hybrid-nanobiocomposite. The process parameters for fabrication of S-GrM hybrid-nanobiocomposite was optimized by RSM based on four responses of easy magnetic separation, biofilm formation along with protein, and carbohydrate contents in extracellular polymeric substances (EPS). The morphology and chemical composition of S-GrM hybrid-nanobiocomposite were investigated using various spectroscopic and microscopic analyses and subsequently explored for removal of Cr3+ ions. The hybrid-nanobiocomposite effectively removed 304.64 ± 14.02 mg/g of Cr3+ at pH 7.0 and 30 °C, which is found to be very high compared to the previously reported values. The high surface area of graphene, biofilm biomass of S. oneidensis and plenty of functional groups provided a unique structure to the S-GrM hybrid-nanobiocomposite for efficient removal of Cr3+ through synergistic interaction. The FTIR and zeta potential studies confirmed that electrostatic and chelation/complexation reaction played key roles in the adsorption process. The fabrication of S-GrM nanobiocomposite thus creates a novel hybrid 'living functional nanomaterial' for low cost, recyclable, and sustainable removal of Cr3+ from wastewater.
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Affiliation(s)
- Baskaran Ramalingam
- Biological Materials Laboratory, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Chennai 600020, India; Department of Civil Engineering, A. C. Tech., Anna University, Chennai, 600020, India
| | - Srinivasan Shanmugham Venkatachalam
- Environmental Engineering Division, Council of Scientific and Industrial Research (CSIR)-Central Leather Research Institute (CLRI), Chennai 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Manikantan Syamala Kiran
- Biological Materials Laboratory, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Chennai 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sujoy K Das
- Biological Materials Laboratory, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Chennai 600020, India; Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Biology (IICB), Kolkata, 700032, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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18
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Ma N, Sun C. Cadmium sulfide nanoparticle biomineralization and biofilm formation mediate cadmium resistance of the deep-sea bacterium Pseudoalteromonas sp. MT33b. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:325-336. [PMID: 33511774 DOI: 10.1111/1758-2229.12933] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/21/2021] [Accepted: 01/24/2021] [Indexed: 06/12/2023]
Abstract
Cadmium (Cd) is a common toxic heavy metal in the environment, and bacteria have evolved different strategies to deal with Cd toxicity. Here, a bacterium designated Pseudoalteromonas sp. MT33b possessing strong Cd resistance was isolated from the Mariana Trench sediments. Supplement of cysteine significantly increased bacterial Cd resistance and removal rate. Biofilm formation was demonstrated to play a positive role toward bacterial Cd resistance. Transcriptome analysis showed the supplement of cysteine effectively prevented Cd2+ from entering bacterial cells, promoted saccharide metabolism and thereby facilitating energy production, which consists well with bacterial growth trend analysed under the same conditions. Notably, the expressions of many biofilm formation related genes including flagellar assembly, signal transduction, bacterial secretion and TonB-dependent transfer system were significantly upregulated when facing Cd stress, indicating their important roles in determining bacterial biofilm formation and enhancing Cd resistance. Overall, this study indicates the formation of insoluble CdS precipitates and massive biofilm is the major strategy adopted by Pseudoalteromonas sp. MT33b to eliminate Cd stress. Our results provide a good model to investigate how heavy metals impact biofilm formation in the deep-sea ecosystems, which may facilitate a deeper understanding of microbial environmental adaptability and better utilization of these microbes for bioremediation purposes in the future.
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Affiliation(s)
- Ning Ma
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- College of Earth Science, University of Chinese Academy of Sciences, Beijing, 100049, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Chaomin Sun
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
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Shen L, Chen R, Wang J, Fan L, Cui L, Zhang Y, Cheng J, Wu X, Li J, Zeng W. Biosorption behavior and mechanism of cadmium from aqueous solutions by Synechocystis sp. PCC6803. RSC Adv 2021; 11:18637-18650. [PMID: 35480929 PMCID: PMC9033491 DOI: 10.1039/d1ra02366g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/16/2021] [Indexed: 02/03/2023] Open
Abstract
Cyanobacteria are promising adsorbents that are widely used for heavy metal removal in aqueous solutions. However, the underlying adsorption mechanism of Synechocystis sp. PCC6803 is currently unclear. In this study, the adsorption behavior and mechanism of cadmium (Cd2+) were investigated. Batch biosorption experiments showed that the optimal adsorption conditions were pH 7.0, 30 °C, 15 min, and an initial ion concentration of 4.0 mg L−1. The adsorption process fitted well with the pseudo-second order kinetic model, mainly based on chemisorption. Complexation of Cd2+ with carboxyl, hydroxyl, carbonyl, and amido groups was demonstrated by Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectrometry (EDX) analyses confirmed the presence of Cd2+ on the cyanobacterial cell surface and intracellularly. Cd2+ could lead to reactive oxygen species (ROS) accumulation and photosynthesis inhibition in cyanobacterial cells, and glutathione (GSH) played an important role in alleviating Cd2+ toxicity. Analyses of three-dimensional fluorescence spectroscopy (3D-EEM) and high performance anion exchange chromatography-pulsed amperometric detection (HPAEC-PAD) revealed the changes of the composition and content of EPS after Cd2+ adsorption, respectively. Real-time quantitative polymerase chain reaction (RT-qPCR) revealed the potential molecular regulatory mechanisms involved in Cd2+ biosorption. These results revealed the adsorption mechanism of Cd2+ by Synechocystis sp. PCC6803 and provided theoretical guidance for insight into the biosorption mechanisms of heavy metals by other strains. The results of extracellular polymeric substances (EPS) extraction, physiological and biochemical determination and gene expression revealed the adsorption mechanism of Synechocystis sp. PCC6803 under cadmium stress.![]()
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Affiliation(s)
- Li Shen
- School of Minerals Processing and Bioengineering
- Central South University
- Changsha 410083
- China
- Key Laboratory of Biometallurgy
| | - Ran Chen
- School of Minerals Processing and Bioengineering
- Central South University
- Changsha 410083
- China
| | - Junjun Wang
- School of Metallurgy and Environment
- Central South University
- Changsha 410083
- China
| | - Ling Fan
- School of Minerals Processing and Bioengineering
- Central South University
- Changsha 410083
- China
| | - Linlin Cui
- School of Minerals Processing and Bioengineering
- Central South University
- Changsha 410083
- China
| | - Yejuan Zhang
- School of Minerals Processing and Bioengineering
- Central South University
- Changsha 410083
- China
| | - Jinju Cheng
- School of Minerals Processing and Bioengineering
- Central South University
- Changsha 410083
- China
| | - Xueling Wu
- School of Minerals Processing and Bioengineering
- Central South University
- Changsha 410083
- China
- Key Laboratory of Biometallurgy
| | - Jiaokun Li
- School of Minerals Processing and Bioengineering
- Central South University
- Changsha 410083
- China
- Key Laboratory of Biometallurgy
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering
- Central South University
- Changsha 410083
- China
- Key Laboratory of Biometallurgy
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Naveed S, Li C, Zhang J, Zhang C, Ge Y. Sorption and transformation of arsenic by extracellular polymeric substances extracted from Synechocystis sp. PCC6803. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 206:111200. [PMID: 32889308 DOI: 10.1016/j.ecoenv.2020.111200] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 06/11/2023]
Abstract
Cyanobacteria widely distribute in the aqueous ecosystem and produce abundant extracellular polymeric substances (EPS), yet little is known about how the quantity and composition of cyanobacterial EPS change upon As exposure, and what are functions of these complex biopolymers in the As sorption and transformation processes. Here we extracted the EPS from Synechocystis sp. PCC6803, characterized their properties, quantified their components upon exposure to arsenite (As(III))/arsenate (As(V)) treatments, and investigated As binding and speciation as affected by the levels of EPS and solution pH. The total binding sites, zeta potential and reducing power of EPS were 17.47 mmol g-1, -19.72 mV and 1.71. The amounts of EPS increased by 22-65.3% and 13.8-39% when the cells were treated with 10-500 μM As(III) and As(V) respectively. The As removal was influenced by the EPS doses and solution pH, with 52.8% at pH 8.5 for As(III) and 49.5% at pH 4.5 for As(V) at 300 mg L-1 EPS. In addition, As speciation was transformed with the addition of EPS. As(V) and As(III) respectively accounted for 4.9-20.3% and 6.5-26.7% of the total dissolved As after the EPS were added (100-300 mg L-1) to the As(III) and As(V) solutions. Fourier transform infrared spectroscopy (FTIR) and three-dimensional excitation-emission fluorescence spectra (3D-EEM) revealed that As was bound to functional groups such as C═O, ─NH, and ─OH in the EPS via surface complexation/hydrophobic interactions. Taken together, this study demonstrated that the EPS extracted from Synechocystis were capable to bind and transform As and could be potentially applied to remove or detoxify As in solutions.
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Affiliation(s)
- Sadiq Naveed
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Chonghua Li
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jinyu Zhang
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Chunhua Zhang
- Demonstration Laboratory of Element and Life Science Research, Laboratory Centre of Life Science, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ying Ge
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
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21
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Xing Y, Luo X, Liu S, Wan W, Huang Q, Chen W. Synergistic effect of biofilm growth and cadmium adsorption via compositional changes of extracellular matrix in montmorillonite system. BIORESOURCE TECHNOLOGY 2020; 315:123742. [PMID: 32659425 DOI: 10.1016/j.biortech.2020.123742] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/21/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
The interaction of bacterial biofilm and clay minerals provides great potential for heavy metal remediation in contaminated soil, yet, little is known about how heavy metal, clay minerals and their combinations affect the bacterial biofilm performance and heavy metal adsorption. In this study, the response of biofilm development as well as Cd2+ adsorption in the presence of Cd2+ and montmorillonite has been deciphered. Low concentrations of Cd2+ and montmorillonite or their combinations enhanced biofilm formation by increasing polysaccharides proportion in the biofilm matrix, and the maximum adsorption capacity of Cd2+ by biofilm was increased by 1.5 times. Furthermore, the immobilization of Cd2+ by soil was significantly improved when S14-biofilm was introduced. Such results could gain deeper insight into bacterial survival tactics in the complex systems which makes major contribution to microbial remediation of heavy metal polluted environments.
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Affiliation(s)
- Yonghui Xing
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Xuesong Luo
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Song Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenjie Wan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenli Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
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22
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Chen X, Zhao Y, Zhang C, Zhang D, Yao C, Meng Q, Zhao R, Wei Z. Speciation, toxicity mechanism and remediation ways of heavy metals during composting: A novel theoretical microbial remediation method is proposed. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 272:111109. [PMID: 32854897 DOI: 10.1016/j.jenvman.2020.111109] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 04/26/2020] [Accepted: 07/15/2020] [Indexed: 06/11/2023]
Abstract
Heavy metals (HM) pollution is a major limitation to the application of composting products. Therefore, mitigating the toxicity of HM has attracted wide attention during composting. The toxicity of HM is mainly acted on microorganisms during composting, and the toxicity of different HM speciation is obviously various. There are many pathways to change the speciation to reduce the toxicity during composting. Therefore, in this review, the speciation distribution, toxicity mechanism and remediation ways of HM during composting were discussed in order to better solve HM pollution. The microbial remediation technology holds enormous potential to remediate for HM without damaging composting, however, it is hard to extract HM. The innovation of this review was to outline microbial remediation strategies for HM during composting based on two mechanisms of microbial remediation: extracellular adsorption and intracellular sequestration, to solve the problem how to extract microbial agents from the compost. Ultimately, a novel theoretical method of microbial remediation was proposed to remove HM from the compost.
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Affiliation(s)
- Xiaomeng Chen
- College of Life Science, Northeast Agricultural University, Harbin, 150030, China
| | - Yue Zhao
- College of Life Science, Northeast Agricultural University, Harbin, 150030, China
| | - Chuang Zhang
- College of Life Science, Northeast Agricultural University, Harbin, 150030, China
| | - Duoying Zhang
- School of Civil Engineering, Heilongjiang University, Harbin, 150080, China
| | - Changhao Yao
- Heilongjiang Province Environmental Monitoring Centre, Harbin, 150056, China
| | - Qingqing Meng
- Heilongjiang Province Environmental Monitoring Centre, Harbin, 150056, China
| | - Ran Zhao
- Heilongjiang Province Environmental Monitoring Centre, Harbin, 150056, China
| | - Zimin Wei
- College of Life Science, Northeast Agricultural University, Harbin, 150030, China.
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23
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Naveed S, Yu Q, Zhang C, Ge Y. Extracellular polymeric substances alter cell surface properties, toxicity, and accumulation of arsenic in Synechocystis PCC6803. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 261:114233. [PMID: 32224289 DOI: 10.1016/j.envpol.2020.114233] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 02/01/2020] [Accepted: 02/17/2020] [Indexed: 06/10/2023]
Abstract
Arsenic (As) contamination of water poses severe threats to human health and thus requires effective remediation methods. In this study, Synechocystis PCC6803, a model cyanobacterium common in aquatic environments, was used to investigate the role of extracellular polymeric substances (EPS) in As toxicity, accumulation, and transformation processes. We monitored the growth of Synechocystis with As exposure, measured the zeta potential and binding sites on the cell surface, and analysed As accumulation and speciation in Synechocystis cells with and without EPS. After EPS removal, the binding sites and zeta potential of the cell surface decreased by 44.43% and 31.9%, respectively. The growth of Synechocystis decreased 49.4% and 43.7% with As(III) and As(V) exposure, and As accumulation in the cells decreased by 12.8-44.5% and 14-42.7%, respectively. As absorption was enhanced in cells with EPS removed. The oxidation of As(III) and reduction of As(V) were significantly greater in cells with intact EPS compared to those with EPS removed. Fourier transform infrared spectroscopy (FTIR) showed that functional groups of EPS and Synechocystis cells, including -NH, -OH, CO, and CC, interacted with As species. Together the results of this work demonstrate that EPS have significant impacts on cell surface properties, thereby affecting As accumulation and transformation in Synechocystis PCC6803. This work provides a basis for using EPS to remedy As pollution in aquatic environments.
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Affiliation(s)
- Sadiq Naveed
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
| | - Qingnan Yu
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
| | - Chunhua Zhang
- Demonstration Laboratory of Element and Life Science Research, Laboratory Centre of Life Science, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China.
| | - Ying Ge
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
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Xia Y, Luo H, Li D, Chen Z, Yang S, Liu Z, Yang T, Gai C. Efficient immobilization of toxic heavy metals in multi-contaminated agricultural soils by amino-functionalized hydrochar: Performance, plant responses and immobilization mechanisms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 261:114217. [PMID: 32113109 DOI: 10.1016/j.envpol.2020.114217] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 02/08/2020] [Accepted: 02/16/2020] [Indexed: 06/10/2023]
Abstract
A novel amino-functionalized hydrochar material (referred to NH2-HCs) was prepared and used as the soil amendment to immobilize multi-contaminated soils for the first time. The results showed that the application of NH2-HCs significantly improved (P < 0.05) soil properties (i.e., pH value, cation exchange capacity and organic content). By introduction of NH2-HCs, the contaminated soil showed the highest value of 96.2%, 52.2% and 15.5% reductions in Cu, Pb and Cd bioavailable concentrations and the leaching toxicity of Cu, Pb and Cd were remarkably reduced by 98.1%, 31.3% and 30.4%, respectively. Most of exchangeable Cu, Pb and Cd reduced were transformed into its less available forms of oxidizable and residual fractions. Potential ecological risk assessment indicated that the element Cd accounted for the most of total risks in NH2-HCs amended soils. The mechanism study indicated that surface complexation, chemical chelating and cation-pi interaction of NH2-HCs played a vital role in the immobilization of heavy metals. Pot experiments further verified that the application of NH2-HCs significantly improved plant growth and reduced metal accumulations. The present study offered a novel approach to prepare amino-functionalized hydrochars with great potential as the green and alternative amendments for efficiently immobilizing heavy metals in multi-contaminated soil.
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Affiliation(s)
- Yu Xia
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hainan Luo
- College of Chemical Engineering and Material Science, Zaozhuang University, Zaozhuang, Shandong Province, 277160, China
| | - Dong Li
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zeliang Chen
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shengshu Yang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhengang Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Tianxue Yang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| | - Chao Gai
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
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Nkoh JN, Yan J, Xu RK, Shi RY, Hong ZN. The mechanism for inhibiting acidification of variable charge soils by adhered Pseudomonas fluorescens. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 260:114049. [PMID: 32014749 DOI: 10.1016/j.envpol.2020.114049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/12/2020] [Accepted: 01/22/2020] [Indexed: 06/10/2023]
Abstract
Acidification in variable charge soils is on the rise due to increased acid deposition and use of nitrogenous fertilizers. The associated low pH and cation exchange capacity make the soils prone to depleted base cations and increased levels of Al3+. Consequently, Al toxicity to plants and soil infertility decrease crop yield. This study was designed to investigate the effect of Pseudomonas fluorescens on the acidification of two Ultisols. The simulated acidification experiment demonstrated that the pH of bacteria-treated soil was higher than that of control under similar conditions, suggesting that the adhered bacteria inhibited soil acidification. This observation was attributed to the association of organic anions (RCOO- or RO-) on bacteria with H+ to form neutral molecules (RCOOH or ROH) and reducing the activity of H+ in solution. The bacteria also inhibited the increase in soil soluble Al and exchangeable Al during soil acidification. The adhesion of bacteria on the soils increased soil effective cation exchange capacity (ECEC) and exchangeable base cations at each pH compared to control. The release of exchangeable base cations from bacteria-treated soil, and the decrease in soil ECEC and exchangeable base cations with decreasing pH confirmed that protonation of organic anions on adhered bacteria was mainly responsible for the inhibition of soil acidification. The change of zeta potential of the bacteria with pH and the ART-FTIR analysis at various pH provided more evidence for this mechanism. Therefore, the bacteria in variable charge soils played an important role in retarding soil acidification.
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Affiliation(s)
- Jackson Nkoh Nkoh
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China; Department of Chemistry, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Jing Yan
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China
| | - Ren-Kou Xu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Ren-Yong Shi
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China
| | - Zhi-Neng Hong
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China
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An electrokinetic perspective into the mechanism of divalent and trivalent cation sorption by extracellular polymeric substances of Pseudomonas fluorescens. Colloids Surf B Biointerfaces 2019; 183:110450. [DOI: 10.1016/j.colsurfb.2019.110450] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 08/04/2019] [Accepted: 08/20/2019] [Indexed: 11/18/2022]
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Nkoh JN, Lu HL, Pan XY, Dong G, Kamran MA, Xu RK. Effects of extracellular polymeric substances of Pseudomonas fluorescens, citrate, and oxalate on Pb sorption by an acidic Ultisol. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 171:790-797. [PMID: 30660972 DOI: 10.1016/j.ecoenv.2019.01.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/09/2019] [Accepted: 01/10/2019] [Indexed: 06/09/2023]
Abstract
The continuous production of low molecular weight (LMW) organic acids by plants and microorganisms coupled with the continuous presence of extracellular polymeric substances (EPS) in soils is a guarantee that the mobility of heavy metals in soils will be controlled. The effects of citrate, oxalate, and EPS on the adsorption of Pb by an acidic Ultisol were studied both as a function of pH and ionic strength. Electrokinetic potential measurements were also employed to observe to what extent each ligand affected the surface charge property of the Ultisol. All the ligands shifted the zeta potential of the Ultisol to the negative direction, implying that the surface charge of the soil became more negative. The effect on the zeta potential of the soil was observed in the order of oxalate ˃ citrate ˃ EPS. The quantity of Pb adsorbed at each pH (3.0-7.0) reflected the corresponding change in the zeta potential as induced by each ligand. The presence of the ligands shifted the isoelectric point of the Ultisol from 4.8 to 3.2 for the EPS system and below 3.0 for the citrate and oxalate systems. More Pb was adsorbed in the presence of oxalate than in the presence of citrate and EPS. The two most outstanding mechanisms that governed the adsorption of Pb by the Ultisol were (1) electrostatic attraction which was supported by the increase in negative zeta potential of the Ultisol and, (2) complexation which was supported by the lesser proportion of Pb adsorbed in the citrate system at higher pH and also by the spectroscopic data for EPS. The combination EPS + citrate + oxalate was more effective in enhancing the adsorption of Pb than the combination EPS + oxalate and EPS + citrate.
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Affiliation(s)
- Jackson Nkoh Nkoh
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; University of Chinese Academy of Sciences, Beijing 100049, China; Department of Chemistry, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Hai-Lung Lu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao-Ying Pan
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ge Dong
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Muhammad Aqeel Kamran
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ren-Kou Xu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, P.O. Box 821, Nanjing, China.
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