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Shi H, Mao X, Yang F, Zhu M, Tan N, Tan W, Gu T, Zhang X. Multi-scale analysis of acidophilic microbial consortium biofilm's tolerance of lithium and cobalt ions in bioleaching. JOURNAL OF HAZARDOUS MATERIALS 2024; 474:134764. [PMID: 38824773 DOI: 10.1016/j.jhazmat.2024.134764] [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: 02/19/2024] [Revised: 05/15/2024] [Accepted: 05/28/2024] [Indexed: 06/04/2024]
Abstract
Metal ions stress will inhibit the oxidation capacity of iron and sulfur of an acidophilic microbial consortium (AMC), which leads to reduced bioleaching efficiency. This work explored the impacts of Li+ and Co2+ on the composition and function of AMC biofilms with a multi-scale approach. At the reactor scale, the results indicated that the oxidative activity, the adsorption capacity, and the biofilm formation ability of AMC on pyrite surfaces decreased under 500 mM Li+ and 500 mM Co2+. At the biofilm scale, the electrochemical measurements showed that Li+ and Co2+ inhibited the charge transfer between the pyrite working electrode and the biofilm, and decreased the corrosion current density of the pyrite working electrode. At the cell scale, the content of proteins in extracellular polymers substrate (EPS) increased as the concentrations of metal ions increased. Moreover, the adsorption capacity of EPS for Li+ and Co2+ increased. At the microbial consortium scale, a BugBase phenotype analysis showed that under 500 mM Li+ and 500 mM Co2+, the antioxidant stress capacity and the content of mobile gene elements in AMC increased. The results in this work can provide useful data and theoretical support for the regulation strategy of the bioleaching of spent lithium-ion batteries to recover valuable metals.
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Affiliation(s)
- Hongjie Shi
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xingshun Mao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Fan Yang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Minglong Zhu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Ningjie Tan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Wensong Tan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Tingyue Gu
- Department of Chemical and Biomolecular Engineering, Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA
| | - Xu Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
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Oubohssaine M, Sbabou L, Aurag J. Potential of the plant growth-promoting rhizobacterium Rhodococcus qingshengii LMR356 in mitigating lead stress impact on Sulla spinosissima L. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:46002-46022. [PMID: 38980484 DOI: 10.1007/s11356-024-34150-8] [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: 02/15/2024] [Accepted: 06/24/2024] [Indexed: 07/10/2024]
Abstract
Mining-related lead (Pb) pollution of the soil poses serious hazards to ecosystems and living organisms, including humans. Improved heavy metal phytoremediation efficacy, achieved by using phytostabilizing plants assisted by plant-growth-promoting (PGP) microorganisms, has been presented as an effective strategy for remediating polluted soils. The objective of this research was to examine the response and potential of the plant-growth-promoting bacterium LMR356, a Rhodococcus qingshengii strain isolated from an abandoned mining soil, under lead stress conditions. Compared to non-contaminated culture media, the presence of lead induced a significant decrease in auxin production (from 21.17 to 2.65 μg mL-1) and phosphate solubilization (from 33.60 to 8.22 mg L-1), whereas other PGP traits increased drastically, such as 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity (from 38.17 to 71.37 nmol mg-1 h-1 α-ketobutyrate), siderophore production (from 69 to 83%), exopolysaccharide production (from 1952.28 to 3637.72 mg mL-1), biofilm formation, and motility. We, therefore, investigated the behavior of Sulla spinosissima L. in the presence or absence of this strain under a variety of experimental conditions. Under hydroponic conditions, Sulla plants showed endurance to varying lead concentrations (500-1000 μM). Inoculation of plants with Rhodococcus qingshengii strain LMR356 enhanced plant tolerance, as demonstrated by the increase in plant biomass (ranging from 14.41 to 79.12%) compared to non-inoculated Pb-stressed and non-stressed control plants. Antioxidant enzyme activities (increasing by -42.71 to 126.8%) and chlorophyll (383.33%) and carotenoid (613.04%) content were also augmented. In addition to its impact on plant lead tolerance, strain LMR356 showed a growth-promoting effect on Sulla plants when cultivated in sterilized non-contaminated sand. Parameters such as plant biomass (16.57%), chlorophyll (24.14%), and carotenoid (30%) contents, as well as ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT) activities, were all elevated compared to non-inoculated plants. Furthermore, when the same plant species was cultivated in highly polluted soil, inoculation increased plant biomass and improved its physiological properties. These findings demonstrate that LMR356 is a phytobeneficial bacterial strain capable of enhancing Sulla growth under normal conditions and improving its heavy metal tolerance in multi-polluted soils. Thus, it can be considered a promising biofertilizer candidate for growing Sulla spinosissima L. or other selected plants intended for application in restoration and stabilization initiatives aimed at reviving and safeguarding environmentally compromised and polluted soils after mining activities.
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Affiliation(s)
- Malika Oubohssaine
- Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, 10000, Rabat, Morocco.
| | - Laila Sbabou
- Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, 10000, Rabat, Morocco
| | - Jamal Aurag
- Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, 10000, Rabat, Morocco
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Hosseini SP, Mousavi SM, Jafari A. Exploring biosynthesis strategies to boost the yield of exopolysaccharide-protein blend from Bacillus arachidis SY8(T), an isolated native strain, as a potent adsorbent for heavy metals removal. Int J Biol Macromol 2024; 271:132634. [PMID: 38797297 DOI: 10.1016/j.ijbiomac.2024.132634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 04/30/2024] [Accepted: 05/23/2024] [Indexed: 05/29/2024]
Abstract
This investigation centers on the synthesis of a polysaccharide-protein blend produced by an isolated native strain (99.12 % phylogenetic affinity with Bacillus arachidis SY8(T)). The primary objective was to investigate the production of extracellular polymeric substances (EPS) under diverse stress conditions, encompassing exposure to heavy metal ions, salt, and toxic agents. Additionally, the impact of environmental parameters, namely pH, inoculation percentage, and time, on the production was investigated. Subsequently, the study examined the biosorption potential of the EPS produced for Pb(II), Cu(II), and Mn(II). The EPS obtained was thoroughly characterized via various tests. Rheological evaluations of an EPS solution (2 wt%) confirmed its pseudo-plastic and non-Newtonian fluid properties, while TGA analysis demonstrated its thermal stability up to 600 °C. Additional analyses, including GPC, FTIR, and H-NMR, provide further insights into the produced EPS. The best conditions for EPS production are determined: 5 % NaCl salt, serving as an effective stress inducer, and 37 °C, pH 6, with a 5 % inoculation, over 96 h. EPS demonstrates remarkable removal efficiencies of 99.9, 99.4 and 78.9 % for Pb(II), Cu(II), and Mn(II), respectively. These findings highlight the potential of EPS as an effective agent for removing heavy metal ions.
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Affiliation(s)
- Seyedeh Parvin Hosseini
- Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, Tehran, Iran
| | - Seyyed Mohammad Mousavi
- Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, Tehran, Iran; Modares Environmental Research Institute, Tarbiat Modares University, Tehran, Iran.
| | - Arezou Jafari
- Chemical Engineering Department, Tarbiat Modares University, Tehran, Iran.
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Lin S, Li J, Jia L, Huang X, Wang L. Different biological responses of Skeletonema costatum and Prorocentrum donghaiense to polymetallic nodules from seawaters. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2024; 269:106871. [PMID: 38402835 DOI: 10.1016/j.aquatox.2024.106871] [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: 12/04/2023] [Revised: 02/18/2024] [Accepted: 02/21/2024] [Indexed: 02/27/2024]
Abstract
The negative impacts of polymetallic nodules mining on deep-sea benthic organisms have been widely established, but there is still a lack of understanding of the environmental impact on the surface ocean scenario. Phytoplankton growth experiment was conducted to determine the biological effect of polymetallic nodules on Prorocentrum donghaiense and Skeletonema costatum. The results showed that regardless of concentration and particle size, polymetallic nodules show a promoting effect on P. donghaiense (p < 0.05), the cell density in the experimental group increased by 35.2%-46.5% compared to the control at the end of the experiment. While fine particles significantly inhibited the growth of S. costatum (p < 0.05), the maximum inhibition rate on cell density reached 63.1%. Polymetallic nodules significantly enhance the Fv/Fm and the maximum electron transport rate of photosystem II in P. donghaiense, thereby increasing its growth rate. However, polymetallic nodules particles stimulated the antioxidant activity and extracellular polymeric substances secretion of S. costatum, resulting in phytoplankton flocculation and sedimentation, which inhibits its growth. Thus, these discriminatory impacts may cause alterations in biomass and community structure, ultimately affecting the ecological function.
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Affiliation(s)
- Shuangshuang Lin
- College of Chemistry, Chemical Engineering & Environmental Science, Minnan Normal University, Zhangzhou 363000, China
| | - Jiandi Li
- College of Chemistry, Chemical Engineering & Environmental Science, Minnan Normal University, Zhangzhou 363000, China
| | - Liping Jia
- College of Chemistry, Chemical Engineering & Environmental Science, Minnan Normal University, Zhangzhou 363000, China; Fujian Province University Key Laboratory of Pollution Monitoring and Control, Minnan Normal University, Zhangzhou 363000, China; Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, China
| | - Xuguang Huang
- College of Chemistry, Chemical Engineering & Environmental Science, Minnan Normal University, Zhangzhou 363000, China; Fujian Province University Key Laboratory of Pollution Monitoring and Control, Minnan Normal University, Zhangzhou 363000, China; Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, China.
| | - Lei Wang
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources P.R.C., Xiamen 361005, China.
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Wang N, Wang X, Chen L, Liu H, Wu Y, Huang M, Fang L. Biological roles of soil microbial consortium on promoting safe crop production in heavy metal(loid) contaminated soil: A systematic review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168994. [PMID: 38043809 DOI: 10.1016/j.scitotenv.2023.168994] [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: 09/14/2023] [Revised: 11/08/2023] [Accepted: 11/27/2023] [Indexed: 12/05/2023]
Abstract
Heavy metal(loid) (HM) pollution of agricultural soils is a growing global environmental concern that affects planetary health. Numerous studies have shown that soil microbial consortia can inhibit the accumulation of HMs in crops. However, our current understanding of the effects and mechanisms of inhibition is fragmented. In this review, we summarise extant studies and knowledge to provide a comprehensive view of HM toxicity on crop growth and development at the biological, cellular and the molecular levels. In a meta-analysis, we find that microbial consortia can improve crop resistance and reduce HM uptake, which in turn promotes healthy crop growth, demonstrating that microbial consortia are more effective than single microorganisms. We then review three main mechanisms by which microbial consortia reduce the toxicity of HMs to crops and inhibit HMs accumulation in crops: 1) reducing the bioavailability of HMs in soil (e.g. biosorption, bioaccumulation and biotransformation); 2) improving crop resistance to HMs (e.g. facilitating the absorption of nutrients); and 3) synergistic effects between microorganisms. Finally, we discuss the prospects of microbial consortium applications in simultaneous crop safety production and soil remediation, indicating that they play a key role in sustainable agricultural development, and conclude by identifying research challenges and future directions for the microbial consortium to promote safe crop production.
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Affiliation(s)
- Na Wang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, The Research Center of Soil and Water Conservation and Ecological Environment, CAS and MOE, Yangling 712100, China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, CAS and MWR, Yangling 712100, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiangxiang Wang
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
| | - Li Chen
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
| | - Hongjie Liu
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
| | - Yanfang Wu
- Palm Eco-Town Development Co., Ltd., Zhengzhou 450000, China
| | - Min Huang
- Key Laboratory of Green Utilization of Critical Nonmetallic Mineral Resources, Ministry of Education, Wuhan University of Technology, Wuhan 430070, China
| | - Linchuan Fang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, The Research Center of Soil and Water Conservation and Ecological Environment, CAS and MOE, Yangling 712100, China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, CAS and MWR, Yangling 712100, China; Key Laboratory of Green Utilization of Critical Nonmetallic Mineral Resources, Ministry of Education, Wuhan University of Technology, Wuhan 430070, China.
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Meng Q, Shi F, Zhong P, Fan W, Xue H, Jiang Y. Transport and interaction of cadmium and active sludge extracellular polymeric substances in saturated sand influenced by ionic strength and composition. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2023; 88:443-453. [PMID: 37522444 PMCID: wst_2023_213 DOI: 10.2166/wst.2023.213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
Artificial groundwater recharge with reclaimed water (secondary effluent from wastewater treatment plants) has become an important approach to solving water scarcity worldwide. Microorganisms in activated sludge can secrete many extracellular polymeric substances (EPS). However, information on the impact of EPS on the movement of heavy metals in porous media and their environmental effects on underground networks is limited. To assess this risk, we extracted EPS from the aerobic section of a wastewater treatment plant using hot sodium hydroxide and conducted experiments using one-dimensional sand columns to investigate how ion composition and strength affect the movement and interaction of cadmium (Cd) and EPS in porous media. The results showed that EPS facilitated Cd migration in porous media. Sodium (Na) and calcium (Ca) ions promoted the migration of Cd in porous media and EPS-Cd complexation. The effect of Ca was more significant than that of Na. As the Na adsorption ratio increased, the migration ability of Cd in porous media and the complexation ability of EPS with Cd decreased. Therefore, when estimating the migration of EPS and Cd in subsurface environments, careful consideration should be given to prevent the risk of groundwater pollution.
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Affiliation(s)
- Qingling Meng
- Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun 130118, China E-mail:
| | - Fuqiang Shi
- Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
| | - Peng Zhong
- Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
| | - Wei Fan
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Honghai Xue
- Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
| | - Yan Jiang
- Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
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Zhang T, Li T, Zhou Z, Li Z, Zhang S, Wang G, Xu X, Pu Y, Jia Y, Liu X, Li Y. Cadmium-resistant phosphate-solubilizing bacteria immobilized on phosphoric acid-ball milling modified biochar enhances soil cadmium passivation and phosphorus bioavailability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162812. [PMID: 36924951 DOI: 10.1016/j.scitotenv.2023.162812] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 02/15/2023] [Accepted: 03/08/2023] [Indexed: 05/06/2023]
Abstract
Cadmium (Cd) can accumulate in agriculture soil from the regular application of phosphorus (P) fertilizer. Microbiological method is considered as a potentially effective strategy that can not only remediate the Cd-contaminated soil but also provide the phosphorus needed for crop growth. However, the toxicity of Cd may affect the activity of microorganisms. To solve this problem, Klebsiella variicola with excellent phosphate solubilization ability (155.30 mg L-1 at 48 h) and Cd adsorption rate (90.84 % with 10 mg L-1 Cd initial concentration) was firstly isolated and identified in this study. Then, a phosphoric acid and ball milling co-modified biochar (PBC) was selected as the carrier to promote the activities of K. variicola under Cd pollution. Surface characterization revealed that the promotion of K. variicola by PBC was mainly attributed to the large specific surface area and diverse functional groups. Compared to contaminated soil, microbial PBC (MPBC) significantly increased the pakchoi biomass and phosphorus (P) content, while the Cd content in leave and root of pakchoi (Brassica chinensis L.) decreased by 25.90-43.46 % (P < 0.05). The combined application also favored the transformation of the resistant P fractions to bioavailable P, and facilitated the immobilization of 20.12 % exchangeable Cd to reducible, oxidizable, and residual Cd in the treated soil. High-throughput sequencing revealed that the response of the soil microbial community to the MPBC was more beneficial than K. variicola or PBC alone. Therefore, the application of MPBC has the potential to act as an efficient, stable, and environmentally friendly sustainable product for Cd remediation and enhanced P bioavailability in agricultural production.
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Affiliation(s)
- Tingrui Zhang
- College of Resources, Sichuan Agricultural University, Chengdu 611130, China
| | - Ting Li
- College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
| | - Zijun Zhou
- Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China
| | - Zengqiang Li
- College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, China
| | - Shirong Zhang
- College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China
| | - Guiyin Wang
- College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiaoxun Xu
- College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China
| | - Yulin Pu
- College of Resources, Sichuan Agricultural University, Chengdu 611130, China
| | - Yongxia Jia
- College of Resources, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiaojing Liu
- College of Resources, Sichuan Agricultural University, Chengdu 611130, China
| | - Yun Li
- College of Resources, Sichuan Agricultural University, Chengdu 611130, China
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Gu T, Lu Y, Li F, Zeng W, Shen L, Yu R, Li J. Microbial extracellular polymeric substances alleviate cadmium toxicity in rice (Oryza sativa L.) by regulating cadmium uptake, subcellular distribution and triggering the expression of stress-related genes. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 257:114958. [PMID: 37116453 DOI: 10.1016/j.ecoenv.2023.114958] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 04/11/2023] [Accepted: 04/23/2023] [Indexed: 05/08/2023]
Abstract
Cadmium (Cd) accumulation in crops causes potential risks to human health. Microbial extracellular polymeric substances (EPS) are a complex mixture of biopolymers that can bind various heavy metals. The present work examined the alleviating effects of EPS on Cd toxicity in rice and its detoxification mechanism. The 100 μM Cd stress hampered the overall plant growth and development, damaged the ultrastructures of both leaf and root cells, and caused severe lipid peroxidation in rice plants. However, applying EPS at a concentration of 100 mg/L during Cd stress resulted in increased biomass, reduced Cd accumulation and transport, and minimized the oxidative damage. EPS application also enhanced Cd retention in the shoot cell walls and root vacuoles, and actively altered the expression of genes involved in cell wall formation, antioxidant defense systems, transcription factors, and hormone metabolism. These findings provide new insights into EPS-mediated mitigation of Cd stress in plants and help us to develop strategies to improve crop yield in Cd-contaminated soils in the future.
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Affiliation(s)
- Tianyuan Gu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, Hubei 430072, China
| | - Yongqing Lu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China
| | - Fang Li
- 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
| | - Li Shen
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China
| | - Runlan Yu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China
| | - Jiaokun Li
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China.
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Shi X, Ling Q, Jiang Z, Pei F, Xin M, Tan W, Chen X, Liu K, Ma J, Yu F, Li Y. Insight into the roles of soluble, loosely bound and tightly bound extracellular polymeric substances produced by Enterobacter sp. in the Cd 2+ and Pb 2+ biosorption process: Characterization and mechanism. Colloids Surf B Biointerfaces 2023; 227:113348. [PMID: 37201449 DOI: 10.1016/j.colsurfb.2023.113348] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/29/2022] [Accepted: 05/12/2023] [Indexed: 05/20/2023]
Abstract
Extracellular polymeric substances (EPSs) are macromolecular polymers formed by metabolic secretion, and they have great potential for removing heavy metal (HM) ions from the aquatic phase. In this study, the contributions of soluble EPSs (S-EPSs), loosely bound EPSs (LB-EPSs) and tightly bound EPSs (TB-EPSs) secreted by Enterobacter sp. to Cd2+ and Pb2+ adsorption were analyzed. The results indicated that in a solution containing both Cd2+ and Pb2+, pH= 6.0 was best suited for the adsorption process, and adsorption equilibrium was reached in approximately 120 min. Moreover, the mechanism for adsorption of Cd2+ and Pb2+ by the different layers of EPSs involved spontaneous chemical processes. However, Cd2+ adsorption by the three layers of the EPSs was an exothermic process (∆H0 <0), but Pb2+ adsorption by the three layers of the EPSs was an endothermic process (∆H0 >0). The variations in zeta potentials indicated that ion exchange occurred during Cd2+ and Pb2+ adsorption. FT-IR, XPS and 3D-EEM analyses indicated that the functional groups of the EPSs involved in adsorption were mainly the CO, C-O and C-O-C groups of the polysaccharides; furthermore, fulvic acid-like substances, humic-like substances and tyrosine-like proteins played important roles in the adsorption of Cd2+ and Pb2+ by the different EPS layers.
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Affiliation(s)
- Xinwei Shi
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Qiujie Ling
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Zhiling Jiang
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Fengmei Pei
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Meifen Xin
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Weilan Tan
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Xuan Chen
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Kehui Liu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, 541004 Guilin, China; College of Life Science, Guangxi Normal University, 541004 Guilin, China
| | - Jiangming Ma
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, 541004 Guilin, China; College of Life Science, Guangxi Normal University, 541004 Guilin, China
| | - Fangming Yu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China.
| | - Yi Li
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China.
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10
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Sharma BD, Olson DG, Giannone RJ, Hettich RL, Lynd LR. Characterization and Amelioration of Filtration Difficulties Encountered in Metabolomic Studies of Clostridium thermocellum at Elevated Sugar Concentrations. Appl Environ Microbiol 2023; 89:e0040623. [PMID: 37039651 PMCID: PMC10132107 DOI: 10.1128/aem.00406-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 03/12/2023] [Indexed: 04/12/2023] Open
Abstract
Clostridium thermocellum, a promising candidate for consolidated bioprocessing, has been subjected to numerous engineering strategies for enhanced bioethanol production. Measurements of intracellular metabolites at substrate concentrations high enough (>50 g/L) to allow the production of industrially relevant titers of ethanol would inform efforts toward this end but have been difficult due to the production of a viscous substance that interferes with the filtration and quenching steps during metabolite extraction. To determine whether this problem is unique to C. thermocellum, we performed filtration experiments with other organisms that have been engineered for high-titer ethanol production, including Escherichia coli and Thermoanaerobacterium saccharolyticum. We addressed the problem through a series of improvements, including active pH control (to reduce problems with viscosity), investigation of different filter materials and pore sizes (to increase the filtration capacity), and correction for extracellular metabolite concentrations, and we developed a technique for more accurate intracellular metabolite measurements at elevated substrate concentrations. IMPORTANCE The accurate measurement of intracellular metabolites (metabolomics) is an integral part of metabolic engineering for the enhanced production of industrially important compounds and a useful technique to understand microbial physiology. Previous work tended to focus on model organisms under laboratory conditions. As we try to perform metabolomic studies with a wider range of organisms under conditions that more closely represent those found in nature or industry, we have found limitations in existing techniques. For example, fast filtration is an important step in quenching metabolism in preparation for metabolite extraction; however, it does not work for cultures of C. thermocellum at high substrate concentrations. In this work, we characterize the extent of the problem and develop techniques to overcome it.
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Affiliation(s)
- Bishal D. Sharma
- Thayer School of Engineering at Dartmouth College, Hanover, New Hampshire, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Daniel G. Olson
- Thayer School of Engineering at Dartmouth College, Hanover, New Hampshire, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Richard J. Giannone
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Robert L. Hettich
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Lee R. Lynd
- Thayer School of Engineering at Dartmouth College, Hanover, New Hampshire, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Enchi Corporation, Holliston, Massachusetts, USA
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11
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Feng W, Xiao X, Li J, Xiao Q, Ma L, Gao Q, Wan Y, Huang Y, Liu T, Luo X, Luo S, Zeng G, Yu K. Bioleaching and immobilizing of copper and zinc using endophytes coupled with biochar-hydroxyapatite: Bipolar remediation for heavy metals contaminated mining soils. CHEMOSPHERE 2023; 315:137730. [PMID: 36603675 DOI: 10.1016/j.chemosphere.2022.137730] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/26/2022] [Accepted: 12/31/2022] [Indexed: 06/17/2023]
Abstract
Copper and zinc are toxic heavy metals in soils that require development of feasible strategies for remediation of contaminated soils around the mine areas. In this study, the processing conditions and mechanisms of immobilization and bioleaching for remediation of highly contaminated soils with heavy metals are investigated. Soil remediation is carried out using a bioleaching-immobilization bipolar method. The results show that LSE03 bacteria provide efficient leaching result and immobilization on Cu2+ and Zn2+. Among the bacterial metabolites, cis, cis-muconic acid and isovaleric acid play major roles in the bioleaching process. The bacterial extracellular polymeric substances are rich in a variety of organic acids that show a significant decrease in content after the adsorption process, indicating that all of these substances are involved in the binding of heavy metals. Characterization of the endophytes and immobilizing agents with FTIR, TEM-mapping, and XPS techniques reveal the ability of both bacteria and composites to adsorb Cu-Zn as well as the main functional groups of -OH, -COOH, -PO43-, and -NH. According to the heavy metals species analyses, competitive adsorption experiments, and bioleaching desorption experiments, it is planned to carry out the bipolar remediation of contaminated soil through immobilization followed by bioleaching process. After bipolar remediation processing, 97.923% and 96.387% of available Cu and Zn are respectively removed. Soils fertility significantly increases in all cases. Our study provides a green, practical, and environmentally friendly treatment method for soils contaminated with high concentrations of heavy metals.
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Affiliation(s)
- Weiran Feng
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
| | - Xiao Xiao
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China.
| | - Junjie Li
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
| | - Qicheng Xiao
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
| | - Li Ma
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
| | - Qifeng Gao
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
| | - Yuke Wan
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
| | - Yutian Huang
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
| | - Ting Liu
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
| | - Xubiao Luo
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China; Key Laboratory of Jiangxi Province for Agricultural Environmental Pollution Prevention and Control in Red Soil Hilly Region, School of Life Sciences, Jinggangshan University, Ji'an, 343009, China
| | - Shenglian Luo
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
| | - Guisheng Zeng
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
| | - Kai Yu
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang, 330063, China
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12
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Manikandan SK, Pallavi P, Shetty K, Bhattacharjee D, Giannakoudakis DA, Katsoyiannis IA, Nair V. Effective Usage of Biochar and Microorganisms for the Removal of Heavy Metal Ions and Pesticides. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020719. [PMID: 36677777 PMCID: PMC9862088 DOI: 10.3390/molecules28020719] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/03/2023] [Accepted: 01/06/2023] [Indexed: 01/12/2023]
Abstract
The bioremediation of heavy metal ions and pesticides is both cost-effective and environmentally friendly. Microbial remediation is considered superior to conventional abiotic remediation processes, due to its cost-effectiveness, decrement of biological and chemical sludge, selectivity toward specific metal ions, and high removal efficiency in dilute effluents. Immobilization technology using biochar as a carrier is one important approach for advancing microbial remediation. This article provides an overview of biochar-based materials, including their design and production strategies, physicochemical properties, and applications as adsorbents and support for microorganisms. Microorganisms that can cope with the various heavy metal ions and/or pesticides that enter the environment are also outlined in this review. Pesticide and heavy metal bioremediation can be influenced by microbial activity, pollutant bioavailability, and environmental factors, such as pH and temperature. Furthermore, by elucidating the interaction mechanisms, this paper summarizes the microbe-mediated remediation of heavy metals and pesticides. In this review, we also compile and discuss those works focusing on the study of various bioremediation strategies utilizing biochar and microorganisms and how the immobilized bacteria on biochar contribute to the improvement of bioremediation strategies. There is also a summary of the sources and harmful effects of pesticides and heavy metals. Finally, based on the research described above, this study outlines the future scope of this field.
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Affiliation(s)
- Soumya K. Manikandan
- Department of Chemical Engineering, National Institute of Technology Karnataka (NITK), Mangalore 575025, India
| | - Pratyasha Pallavi
- Department of Chemical Engineering, National Institute of Technology Karnataka (NITK), Mangalore 575025, India
| | - Krishan Shetty
- Department of Chemical Engineering, National Institute of Technology Karnataka (NITK), Mangalore 575025, India
| | | | - Dimitrios A. Giannakoudakis
- Laboratory of Chemical and Environmental Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
- Correspondence: (D.A.G.); (V.N.)
| | - Ioannis A. Katsoyiannis
- Laboratory of Chemical and Environmental Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Vaishakh Nair
- Department of Chemical Engineering, National Institute of Technology Karnataka (NITK), Mangalore 575025, India
- Correspondence: (D.A.G.); (V.N.)
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13
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Li Y, Shi X, Ling Q, Li S, Wei J, Xin M, Xie D, Chen X, Liu K, Yu F. Bacterial extracellular polymeric substances: Impact on soil microbial community composition and their potential role in heavy metal-contaminated soil. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 240:113701. [PMID: 35636237 DOI: 10.1016/j.ecoenv.2022.113701] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/21/2022] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
In this study, six different treatments involving extracellular polymeric substances (EPS) from Enterobacter sp. FM-1 (FM-1) (no EPS (control), original bacterial cells (FM-1), FM-1 cells with EPS artificially removed (EPS-free cells, EPS-R), different forms of EPS (soluble EPS (S-EPS), loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS)) obtained from FM-1) and three types of soils (non-contaminated soil (NC soil), high-contamination soil (HC soil) and low-contamination soil (LC soil)) were used to investigate the impact of different EPS treatments on soil microbial community composition and their potential role in the remediation of heavy metal (HM)-contaminated soil. The results indicate that the EPS secreted by FM-1 played a vital role in changing soil pH and helped increase soil bio- HMs. In addition, EPS secretion by FM-1 helped increase the soil EPS-polysaccharide and EPS-nucleic acid contents; even in HC soil, where the HM content was relatively high, LB-EPS addition still increased the EPS-polysaccharide and EPS-nucleic acid contents in the soil by 1.18- and 15.54-fold, respectively. FM-1, LB-EPS and TB-EPS addition increased the soil invertase, urease and alkaline phosphatase activities and increased the soil organic matter (SOM), NH4+-N and available phosphorus (AP) contents, which helped regulate soil nutrient reserves. Moreover, the addition of different EPS fractions modified the soil microbial community composition to help microbes adapt to an HM-contaminated environment. In the HC and LC soils, where the HM content was relatively high, the soil bacteria were dominated by Protobacteria, while fungi in the soil were dominated by Ascomycota. Among the soil physicochemical properties, the soil SOM and NH4+-N contents and invertase activity significantly impacted the diversity and community composition of both bacteria and fungi in the soil.
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Affiliation(s)
- Yi Li
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Xinwei Shi
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Qiujie Ling
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Songying Li
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Jiayu Wei
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Meifen Xin
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Dongyu Xie
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Xuan Chen
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Kehui Liu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Life Science, Guangxi Normal University, 541004 Guilin, China; Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, 541004 Guilin, China.
| | - Fangming Yu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China.
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14
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Lysozyme regulates the extracellular polymer of activated sludge and promotes the formation of electroactive biofilm. Bioprocess Biosyst Eng 2022; 45:1065-1074. [PMID: 35511298 DOI: 10.1007/s00449-022-02727-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 04/08/2022] [Indexed: 11/02/2022]
Abstract
The formation of electroactive biofilm from activated sludge on electrode surface is a key step to construct a bio-electrochemical system, yet it is greatly limited by the poor affinity between the bacteria and the electrode interface. Herein, we report a new method to promote the formation of electroactive biofilm by regulating the extracellular polymeric substance (EPS) content in activated sludge with lysozyme. The investigation of the effect of lysozyme treatment on the content of extracellular polymers and the biofilm formation of electroactive bacteria suggests that lysozyme can improve the permeability of the positive bacterial cell membrane and thus increase the EPS content in the activated sludge. The characterizations of electrochemical activity, surface morphology and community structure of the anode biofilm indicate that increasing EPS content promotes the adhesion of the mixed bacteria in the activated sludge on the electrode and results in denser biofilms with better conductivities. The microbial fuel cell (MFC) inoculated with the sludge of high EPS content exhibits the power density up to 2.195 W/m2, much higher than that inoculated with the untreated sludge (1.545 W/m2). The strategy of adjusting EPS content in activated sludge with a biological enzyme can effectively enhance the ability of the bacterial community to form biofilms and exhibits great application potentials in the construction of high efficiency bio-electrochemical systems.
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15
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Fang X, Sun S, Liao X, Li S, Zhou S, Gan Q, Zeng L, Guan Z. Effect of diurnal temperature range on bioleaching of sulfide ore by an artificial microbial consortium. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150234. [PMID: 34562759 DOI: 10.1016/j.scitotenv.2021.150234] [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: 06/18/2021] [Revised: 08/28/2021] [Accepted: 09/05/2021] [Indexed: 06/13/2023]
Abstract
Temperature is considered to be one of the main factors affecting bioleaching, but few studies have assessed the effects of diurnal temperature range (DTR) on the bioleaching process. This study investigates the effects of different bioleaching temperatures (30 and 40 °C) and DTR on the bioleaching of metal sulfide ores by microbial communities. The results showed that DTR had an obvious inhibitory effect on the bioleaching efficiency of the artificial microbial community, although this effect was mainly concentrated in the early and middle stages (0-18 days) of exposure, gradually decreasing until almost disappearing in the late stage (18-24 days). Extracellular polymeric substance (EPS) analysis showed that DTR did not change the composition of the EPS matrix (humic acid-like substances, polysaccharides and protein-like substances), but had a significant effect on the generative behavior of EPS, inhibiting the secretion of EPS during the early and middle stages of the bioleaching process. However, the continual increase in EPS secretion in the bioleaching system gradually reduced the adverse effects of DTR on mineral dissolution. X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Scanning electron microscopy- energy dispersive spectrometry (SEM-EDS) analysis of the bioleached residue showed that DTR had no obvious effect on the mineralogical characteristics of sulfide ore. Therefore, in industrial sulfide ore bioleaching applications, in order to accelerate the artificial microbial community start-up process, temperature control measures should be increased in the bioleaching process to reduce the adverse effects of DTR on mineral dissolution.
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Affiliation(s)
- Xiaodi Fang
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Shuiyu Sun
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangdong Polytechnic of Environmental Protection Engineering, Foshan 528216, China
| | - Xiaojian Liao
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Shoupeng Li
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
| | - Siyu Zhou
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Qiaowei Gan
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Liuting Zeng
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Zhijie Guan
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
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16
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Li Y, Mo L, Zhou X, Yao Y, Ma J, Liu K, Yu F. Characterization of plant growth-promoting traits of Enterobacter sp. and its ability to promote cadmium/lead accumulation in Centella asiatica L. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:4101-4115. [PMID: 34405329 DOI: 10.1007/s11356-021-15948-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 08/09/2021] [Indexed: 05/22/2023]
Abstract
In the present study, we characterized the plant growth-promoting traits of Enterobacter sp. FM-1 (FM-1) and investigated its ability to promote growth and increase IAA, P, and Fe concentrations as well as Cd and Pb accumulation in Centella asiatica L. (C. asiatica L.) in upstream area (UA) soil and downstream area (DA) soil that we collected from Siding mine. The results demonstrated that FM-1 secreted IAA, produced siderophores, and had P-solubilization ability even under Cd exposure. IAA secretion reached a maximum of 108.3 ± 1.3 mg L-1 under Cd exposure at 25 mg L-1. Siderophore production reached a maximum of 0.94 ± 0.01 under Cd exposure at 50 mg L-1. Pot experiments indicated that FM-1 successfully colonized the roots of C. asiatica L. In both soils, inoculation with FM-1 decreased the pH in rhizosphere soil and increased the bioavailability of both Cd and Pb. In addition, inoculation with FM-1 increased the IAA, P, and Fe concentrations and simultaneously promoted both Cd and Pb accumulation in C. asiatica L. The Cd and Pb concentrations in leaves increased 1.73- and 1.07-fold in the UA soil and 1.25- and 1.11-fold in the DA soil, respectively. Thus, the Cd-resistant strain FM-1 presented excellent PGP traits and could facilitate Cd and Pb phytoremediation by C. asiatica L.
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Affiliation(s)
- Yi Li
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, China
- College of Life Science, Guangxi Normal University, 15th YuCai St., QiXing District, Guilin, 541004, China
- College of Life Science, Guangxi Normal University, 15th YuCai St., QiXing District, Guilin, 541004, China
| | - Lijuan Mo
- College of Life Science, Guangxi Normal University, 15th YuCai St., QiXing District, Guilin, 541004, China
| | - Xiaoqin Zhou
- College of Life Science, Guangxi Normal University, 15th YuCai St., QiXing District, Guilin, 541004, China
| | - Yawei Yao
- College of Life Science, Guangxi Normal University, 15th YuCai St., QiXing District, Guilin, 541004, China
| | - Jiangming Ma
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, China
- Innovation Institute of Sustainable Development, Guangxi Normal University, Guilin, 541004, China
- College of Life Science, Guangxi Normal University, 15th YuCai St., QiXing District, Guilin, 541004, China
| | - Kehui Liu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, China.
- Innovation Institute of Sustainable Development, Guangxi Normal University, Guilin, 541004, China.
- College of Life Science, Guangxi Normal University, 15th YuCai St., QiXing District, Guilin, 541004, China.
| | - Fangming Yu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, China.
- College of Life Science, Guangxi Normal University, 15th YuCai St., QiXing District, Guilin, 541004, China.
- College of Life Science, Guangxi Normal University, 15th YuCai St., QiXing District, Guilin, 541004, China.
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17
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Kumar M, Tierney J, Wilkinson M. Enzymatic Disruption of Biofilms During Cheese Manufacturing: A Mini Review. Front Microbiol 2021; 12:791061. [PMID: 34975813 PMCID: PMC8716882 DOI: 10.3389/fmicb.2021.791061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022] Open
Abstract
Bacteria are capable of colonizing industrial processing surfaces creating biofilms on them which may adversely affect the quality and safety of products. Traditional cleaning-in-place (CIP) treatments using caustic and nitric acid solutions have been known to exhibit variable efficiency in eliminating biofilm bacteria. Here, we introduce enzymes as an alternative to traditional CIP treatments and discuss their mechanism of action against bacterial biofilms in cheese manufacturing. In addition, we discuss research gaps namely thermal stability, substrate specificity and residual activity of enzymes that may play a vital role in the selection of enzymes with optimal effectiveness against multi species biofilms. The outcome of this mini review will aid in the development of a novel and sustainable enzyme-based CIP treatment during cheese manufacturing in the future.
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Affiliation(s)
- Murali Kumar
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
- *Correspondence: Murali Kumar,
| | | | - Martin Wilkinson
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
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Abstract
In view of high energy cost and water consumption in microalgae cultivation, microalgal-biofilm-based cultivation system has been advocated as a solution toward a more sustainable and resource friendlier system for microalgal biomass production. Algal-derived extracellular polymeric substances (EPS) form cohesive network to interconnect the cells and substrates; however, their interactions within the biofilm are poorly understood. This scenario impedes the biofilm process development toward resource recovery. Herein, this review elucidates on various biofilm cultivation modes and contribution of EPS toward biofilm adhesion. Immobilized microalgae can be envisioned by the colloid interactions in terms of a balance of both dispersive and polar interactions among three interfaces (cells, mediums and substrates). Last portion of this review is dedicated to the future perspectives and challenges on the EPS; with regard to the biopolymers extraction, biopolymers’ functional description and cross-referencing between model biofilms and full-scale biofilm systems are evaluated. This review will serve as an informative reference for readers having interest in microalgal biofilm phenomenon by incorporating the three main players in attached cultivation systems: microalgae, EPS and supporting materials. The ability to mass produce these miniature cellular biochemical factories via immobilized biofilm technology will lay the groundwork for a more sustainable and feasible production.
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Affiliation(s)
- Yi Tong Cheah
- School of Chemical Engineering, Engineering Campus, University of Science Malaysia, Nibong Tebal, Penang, Malaysia
| | - Derek Juinn Chieh Chan
- School of Chemical Engineering, Engineering Campus, University of Science Malaysia, Nibong Tebal, Penang, Malaysia
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19
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Extracellular Polymeric Substances (EPS) as Microalgal Bioproducts: A Review of Factors Affecting EPS Synthesis and Application in Flocculation Processes. ENERGIES 2021. [DOI: 10.3390/en14134007] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Microalgae are natural resources of intracellular compounds with a wide spectrum of applications in, e.g., the food industry, pharmacy, and biofuel production. The extracellular polymeric substances (EPS) released by microalgal cells are a valuable bioproduct. Polysaccharides, protein, lipids, and DNA are the main constituents of EPS. This review presents the recent advances in the field of the determinants of the synthesis of extracellular polymeric substances by microalgal cells and the EPS structure. Physical and chemical culture conditions have been analyzed to achieve useful insights into the development of a strategy optimizing EPS production by microalgal cells. The application of microalgal EPS for flocculation and mechanisms involved in this process are also discussed in terms of biomass harvesting. Additionally, the ability of EPS to remove toxic heavy metals has been analyzed. With their flocculation and sorption properties, microalgal EPS are a promising bioproduct that can potentially be used in harvesting algal biomass and wastewater management.
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