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Qi X, Fu K, Yue M, Shou N, Yuan X, Chen X, He C, Yang Y, Shi Z. Kynurenic acid mediates bacteria-algae consortium in resisting environmental cadmium toxicity. JOURNAL OF HAZARDOUS MATERIALS 2023; 444:130397. [PMID: 36403444 DOI: 10.1016/j.jhazmat.2022.130397] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/07/2022] [Accepted: 11/12/2022] [Indexed: 06/16/2023]
Abstract
Cadmium (Cd2+) is a toxic heavy metal in the environment, posing severe damage to animal health and drinking water safety. The bacteria-algae consortium remediates environmental Cd2+ pollution by secreting chelating reagents, but the molecular mechanisms remain elusive. Here, we showed that Cellulosimicrobium sp. SH8 isolated from a Cd2+-polluted lake could interact with Synechocystis sp. PCC6803, a model species of cyanobacteria, in strengthening Cd2+ toxicity resistance, while SH8 or PCC6803 alone barely immobilized Cd2+. In addition, the SH8-PCC6803 consortium, but not SH8 alone, could grow in a carbon-free medium, suggesting that autotrophic PCC6803 enabled the growth of heterotrophic SH8. Totally, 12 metabolites were significantly changed when SH8 was added to PCC6803 culture in the presence of Cd2+ (PCC6803/Cd2+). Among them, kynurenic acid was the only metabolite that precipitated Cd2+. Remarkably, adding kynurenic acid increased the growth of PCC6803/Cd2+ by 14.1 times. Consistently, the expressions of kynA, kynB, and kynT genes, known to be essential for kynurenic acid synthesis, were considerably increased when SH8 was added to PCC6803/Cd2+. Collectively, kynurenic acid secreted by SH8 mitigates Cd2+ toxicity for algae, and algae provide organic carbon for the growth of SH8, unveiling a critical link that mediates beneficial bacteria-algae interaction to resist Cd2+.
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Affiliation(s)
- Xiaoli Qi
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China; National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Keyi Fu
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Mingyuan Yue
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Na Shou
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Xuefeng Yuan
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Xi Chen
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Chunyu He
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Yunfeng Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
| | - Zunji Shi
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China.
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Wang X, Xu Q, Hu K, Wang G, Shi K. A Coculture of Enterobacter and Comamonas Species Reduces Cadmium Accumulation in Rice. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:95-108. [PMID: 36366828 DOI: 10.1094/mpmi-09-22-0186-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The accumulation of cadmium (Cd) in plants is strongly impacted by soil microbes, but its mechanism remains poorly understood. Here, we report the mechanism of reduced Cd accumulation in rice by coculture of Enterobacter and Comamonas species. In pot experiments, inoculation with the coculture decreased Cd content in rice grain and increased the amount of nonbioavailable Cd in Cd-spiked soils. Fluorescence in situ hybridization and scanning electron microscopy detection showed that the coculture colonized in the rhizosphere and rice root vascular tissue and intercellular space. Soil metagenomics data showed that the coculture increased the abundance of sulfate reduction and biofilm formation genes and related bacterial species. Moreover, the coculture increased the content of organic matter, available nitrogen, and potassium and increased the activities of arylsulfatase, β-galactosidase, phenoloxidase, arylamidase, urease, dehydrogenase, and peroxidase in soils. In subsequent rice transcriptomics assays, we found that the inoculation with coculture activated a hypersensitive response, defense-related induction, and mitogen-activated protein kinase signaling pathway in rice. Heterologous protein expression in yeast confirmed the function of four Cd-binding proteins (HIP28-1, HIP28-4, BCP2, and CID8), a Cd efflux protein (BCP1), and three Cd uptake proteins (COPT4, NRAM5, and HKT6) in rice. Succinic acid and phenylalanine were subsequently proved to inhibit rice divalent Cd [Cd(II)] uptake and activate Cd(II) efflux in rice roots. Thus, we propose a model that the coculture protects rice against Cd stress via Cd immobilization in soils and reducing Cd uptake in rice. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Xing Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Qing Xu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Kang Hu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Kaixiang Shi
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
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Shan S, Cheng W, Li Y, Zhang M, Liu Z, Wang Y, Wei X, Fu Z, Wu S, Du D, Guo Z. Comparative genomic analysis of Citrobacter sp. XT1-2-2 reveals insights into the molecular mechanism of microbial immobilization of heavy metals. BMC Genomics 2022; 23:838. [PMID: 36536293 PMCID: PMC9764585 DOI: 10.1186/s12864-022-09069-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND In our previous study, Citrobacter sp. XT1-2-2 was isolated from high cadmium-contaminated soils, and demonstrated an excellent ability to decrease the bioavailability of cadmium in the soil and inhibit cadmium uptake in rice. In addition, the strain XT1-2-2 could significantly promote rice growth and increase rice biomass. Therefore, the strain XT1-2-2 shows great potential for remediation of cadmium -contaminated soils. However, the genome sequence of this organism has not been reported so far. RESULTS: Here the basic characteristics and genetic diversity of the strain XT1-2-2 were described, together with the draft genome and comparative genomic results. The strain XT1-2-2 is 5040459 bp long with an average G + C content of 52.09%, and contains a total of 4801 genes. Putative genomic islands were predicted in the genome of Citrobacter sp. XT1-2-2. All genes of a complete set of sulfate reduction pathway and various putative heavy metal resistance genes in the genome were identified and analyzed. CONCLUSIONS These analytical results provide insights into the genomic basis of microbial immobilization of heavy metals.
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Affiliation(s)
- Shiping Shan
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China ,Hunan Engineering and Technology Research Center of Agricultural Microbiology Application, 410009 Changsha, Hunan China
| | - Wei Cheng
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China
| | - Yilu Li
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China
| | - Min Zhang
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China
| | - Zhudong Liu
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China
| | - Yushuang Wang
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China
| | - Xiaowu Wei
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China
| | - Zujiao Fu
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China
| | - Shandong Wu
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China
| | - Dongxia Du
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China
| | - Zhaohui Guo
- grid.506983.1Hunan Institute of Microbiology, 410009 Changsha, Hunan China ,Hunan Engineering and Technology Research Center of Agricultural Microbiology Application, 410009 Changsha, Hunan China
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Ao B, He F, Lv J, Tu J, Tan Z, Jiang H, Shi X, Li J, Hou J, Hu Y, Xia X. Green synthesis of biogenetic Te(0) nanoparticles by high tellurite tolerance fungus Mortierella sp. AB1 with antibacterial activity. Front Microbiol 2022; 13:1020179. [PMID: 36274686 PMCID: PMC9581301 DOI: 10.3389/fmicb.2022.1020179] [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: 08/15/2022] [Accepted: 09/20/2022] [Indexed: 11/17/2022] Open
Abstract
Tellurite [Te(IV)] is a high-toxicity metalloid. In this study, a fungus with high Te(IV) resistance was isolated. Strain AB1 could efficiently reduce highly toxic Te(IV) to less toxic Te(0). The reduced products formed rod-shaped biogenetic Te(0) nanoparticles (Bio-TeNPs) intracellularly. Further TEM-element mapping, FTIR, and XPS analysis showed that the extracted Bio-TeNPs ranged from 100 to 500 nm and consisted of Te(0), proteins, lipids, aromatic compounds, and carbohydrates. Moreover, Bio-TeNPs exhibited excellent antibacterial ability against Shigella dysenteriae, Escherichia coli, Enterobacter sakazakii, and Salmonella typhimurium according to inhibition zone tests. Further growth and live/dead staining experiments showed that E. coli and S. typhimurium were significantly inhibited by Bio-TeNPs, and cells were broken or shriveled after treatment with Bio-TeNPs based on SEM observation. Additionally, the antioxidant and cytotoxicity tests showed that the Bio-TeNPs exhibited excellent antioxidant capacity with no cytotoxicity. All these results suggested that strain AB1 showed great potential in bioremediation and Bio-TeNPs were excellent antibacterial nanomaterials with no cytotoxicity.
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Affiliation(s)
- Bo Ao
- Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization, Huangshi Key Laboratory of Lake Environmental Protection and Sustainable Utilization of Resources, Hubei Engineering Research Center of Characteristic Wild Vegetable Breeding and Comprehensive Utilization Technology, Hubei Normal University, Huangshi, China
| | - Fei He
- Hubei Provincial Center for Disease Control and Prevention, Wuhan, China
| | - Jing Lv
- Hubei Provincial Center for Disease Control and Prevention, Wuhan, China
| | - Junming Tu
- Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization, Huangshi Key Laboratory of Lake Environmental Protection and Sustainable Utilization of Resources, Hubei Engineering Research Center of Characteristic Wild Vegetable Breeding and Comprehensive Utilization Technology, Hubei Normal University, Huangshi, China
| | - Zheng Tan
- Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization, Huangshi Key Laboratory of Lake Environmental Protection and Sustainable Utilization of Resources, Hubei Engineering Research Center of Characteristic Wild Vegetable Breeding and Comprehensive Utilization Technology, Hubei Normal University, Huangshi, China
| | - Honglin Jiang
- Hubei Provincial Center for Disease Control and Prevention, Wuhan, China
| | - Xiaoshan Shi
- Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization, Huangshi Key Laboratory of Lake Environmental Protection and Sustainable Utilization of Resources, Hubei Engineering Research Center of Characteristic Wild Vegetable Breeding and Comprehensive Utilization Technology, Hubei Normal University, Huangshi, China
| | - Jingjing Li
- Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization, Huangshi Key Laboratory of Lake Environmental Protection and Sustainable Utilization of Resources, Hubei Engineering Research Center of Characteristic Wild Vegetable Breeding and Comprehensive Utilization Technology, Hubei Normal University, Huangshi, China
- Department of Virology, University of Helsinki, Helsinki, Finland
| | - Jianjun Hou
- Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization, Huangshi Key Laboratory of Lake Environmental Protection and Sustainable Utilization of Resources, Hubei Engineering Research Center of Characteristic Wild Vegetable Breeding and Comprehensive Utilization Technology, Hubei Normal University, Huangshi, China
| | - Yuanliang Hu
- Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization, Huangshi Key Laboratory of Lake Environmental Protection and Sustainable Utilization of Resources, Hubei Engineering Research Center of Characteristic Wild Vegetable Breeding and Comprehensive Utilization Technology, Hubei Normal University, Huangshi, China
| | - Xian Xia
- Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization, Huangshi Key Laboratory of Lake Environmental Protection and Sustainable Utilization of Resources, Hubei Engineering Research Center of Characteristic Wild Vegetable Breeding and Comprehensive Utilization Technology, Hubei Normal University, Huangshi, China
- *Correspondence: Xian Xia,
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Ao B, Lv J, Yang H, He F, Hu Y, Hu B, Jiang H, Huo X, Tu J, Xia X. Moringa oleifera extract mediated the synthesis of Bio-SeNPs with antibacterial activity against Listeria monocytogenes and Corynebacterium diphtheriae. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.113751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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6
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Zhou Z, Zhu L, Dong Y, You L, Zheng S, Wang G, Xia X. Identification of a Novel Chromate and Selenite Reductase FesR in Alishewanella sp. WH16-1. Front Microbiol 2022; 13:834293. [PMID: 35350625 PMCID: PMC8957926 DOI: 10.3389/fmicb.2022.834293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/10/2022] [Indexed: 12/04/2022] Open
Abstract
A ferredoxin protein (AAY72_06850, named FesR) was identified to associate with chromate [Cr(VI)] resistance in Alishewanella sp. WH16-1. FesR and its similar proteins were phylogenetically separated from other reductase families. Unlike the reported Cr(VI) and selenite [Se(IV)] reductases, two 4Fe-4S clusters and one flavin adenine dinucleotide (FAD) -binding domain were found in the FesR sequence. The experiment in vivo showed that the mutant strain ΔfesR had lost partial Cr(VI) and Se(IV) reduction capacities compared to the wild-type and complemented strains. Furthermore, overexpression in Escherichia coli and enzymatic tests in vitro showed FesR were involved in Cr(VI) and Se(IV) reduction. 4Fe-4S cluster in purified FesR was detected by ultraviolet-visible spectrum (UV-VIS) and Electron Paramagnetic Resonance (EPR). The Km values of FesR for Cr(VI) and Se(IV) reduction were 1682.0 ± 126.2 and 1164.0 ± 89.4 μmol/L, and the Vmax values for Cr(VI) and Se(IV) reduction were 4.1 ± 0.1 and 9.4 ± 0.3 μmol min–1 mg–1, respectively. Additionally, site-directed mutagenesis and redox potential analyses showed that 4Fe-4S clusters were essential to FesR, and FAD could enhance the enzyme efficiencies of FesR as intracellular electron transporters. To the best of our knowledge, FesR is a novel Cr(VI) and Se(IV) reductase.
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Affiliation(s)
- Zijie Zhou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Lin Zhu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yixuan Dong
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Lexing You
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Shixue Zheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xian Xia
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.,Hubei Key Laboratory of Edible Wild Plants Conservation & Utilization, Huangshi Key Laboratory of Lake Environmental Protection and Sustainable Utilization of Resources, Hubei Engineering Research Center of Characteristic Wild Vegetable Breeding and Comprehensive Utilization Technology, College of Life Sciences, Hubei Normal University, Huangshi, China
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7
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Yu Y, Shi K, Li X, Luo X, Wang M, Li L, Wang G, Li M. Reducing cadmium in rice using metallothionein surface-engineered bacteria WH16-1-MT. ENVIRONMENTAL RESEARCH 2022; 203:111801. [PMID: 34339701 DOI: 10.1016/j.envres.2021.111801] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Cadmium (Cd) accumulation in rice grains poses a health risk for humans. In this study, a bacterium, Alishewanella sp. WH16-1-MT, was engineered to express metallothionein on the cell surface. Compared with the parental WH16-1 strain, Cd2+ adsorption efficiency of WH16-1-MT in medium was increased from 1.2 to 2.6 mg/kg dry weight. The WH16-1-MT strain was then incubated with rice in moderately Cd-contaminated paddy soil. Compared with WH16-1, inoculation with WH16-1-MT increased plant height, panicle length and thousand-kernel weight, and decreased the levels of ascorbic acid and glutathione and the activity of peroxidase. Compared with WH16-1, WH16-1-MT inoculation significantly reduced the concentrations of Cd in brown rice, husks, roots and shoots by 44.0 %, 45.5 %, 36.1 % and 47.2 %, respectively. Moreover, inoculation with WH16-1-MT reduced the bioavailability of Cd in soil, with the total Cd proportion in oxidizable and residual states increased from 29 % to 32 %. Microbiome analysis demonstrated that the addition of WH16-1-MT did not significantly alter the original bacterial abundance and community structure in soil. These results indicate that WH16-1-MT can be used as a novel microbial treatment approach to reduce Cd in rice grown in moderately Cd-contaminated paddy soil.
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Affiliation(s)
- Ying Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, PR China
| | - Kaixiang Shi
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, PR China
| | - Xuexue Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, PR China
| | - Xiong Luo
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, PR China
| | - Mengjie Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, PR China
| | - Lin Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, PR China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, PR China
| | - Mingshun Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, PR China.
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He Y, Huang D, Li S, Shi L, Sun W, Sanford RA, Fan H, Wang M, Li B, Li Y, Tang X, Dong Y. Profiling of Microbial Communities in the Sediments of Jinsha River Watershed Exposed to Different Levels of Impacts by the Vanadium Industry, Panzhihua, China. MICROBIAL ECOLOGY 2021; 82:623-637. [PMID: 33580272 DOI: 10.1007/s00248-021-01708-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 02/01/2021] [Indexed: 05/25/2023]
Abstract
The mining, smelting, manufacturing, and disposal of vanadium (V) and associated products have caused serious environmental problems. Although the microbial ecology in V-contaminated soils has been intensively studied, the impacted watershed ecosystems have not been systematically investigated. In this study, geochemistry and microbial structure were analyzed along ~30 km of the Jinsha River and its two tributaries across the industrial areas in Panzhihua, one of the primary V mining and production cities in China. Geochemical analyses showed different levels of contamination by metals and metalloids in the sediments, with high degrees of contamination observed in one of the tributaries close to the industrial park. Analyses of the V4 hypervariable region of 16S rRNA genes of the microbial communities in the sediments showed significant decrease in microbial diversity and microbial structure in response to the environmental gradient (e.g., heavy metals, total sulfur, and total nitrogen). Strong association of the taxa (e.g., Thauera, Algoriphagus, Denitromonas, and Fontibacter species) with the metals suggested selection for these potential metal-resistant and/or metabolizing populations. Further co-occurrence network analysis showed that many identified potential metal-mediating species were among the keystone taxa that were closely associated in the same module, suggesting their strong inter-species interactions but relative independence from other microorganisms in the hydrodynamic ecosystems. This study provided new insight into the microbe-environment interactions in watershed ecosystems differently impacted by the V industries. Some of the phylotypes identified in the highly contaminated samples exhibited potential for bioremediation of toxic metals (e.g., V and Cr).
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Affiliation(s)
- Yu He
- School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China
| | - Dongmei Huang
- School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China
| | - Shuyi Li
- School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China
| | - Liang Shi
- School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan, China
| | - Weimin Sun
- Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, China
| | - Robert A Sanford
- Department of Geology, University of Illinois Urbana-Champaign, Champaign, USA
| | - Hao Fan
- Changjiang Water Resources Protection Institute, Wuhan, China
| | - Meng Wang
- Changjiang Water Resources Protection Institute, Wuhan, China
| | - Baoqin Li
- Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, China
| | - Ye Li
- School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, China
| | - Xiliang Tang
- China Three Gorges Projects Development Co., Ltd, Beijing, China
| | - Yiran Dong
- School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China.
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan, China.
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Fay M, Salazar JK, Ramachandran P, Stewart D. Microbiomes of commercially-available pine nuts and sesame seeds. PLoS One 2021; 16:e0252605. [PMID: 34153055 PMCID: PMC8216511 DOI: 10.1371/journal.pone.0252605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 04/23/2021] [Indexed: 01/21/2023] Open
Abstract
Metagenomic analysis of food is becoming more routine and can provide important information pertaining to the shelf life potential and the safety of these products. However, less information is available on the microbiomes associated with low water activity foods. Pine nuts and sesame seeds, and food products which contain these ingredients, have been associated with recalls due to contamination with bacterial foodborne pathogens. The objective of this study was to identify the microbial community of pine nuts and sesame seeds using targeted 16S rRNA sequencing technology. Ten different brands of each seed type were assessed, and core microbiomes were determined. A total of 21 and 16 unique taxa with proportional abundances >1% in at least one brand were identified in the pine nuts and sesame seeds, respectively. Members of the core pine nut microbiome included the genera Alishewanella, Aminivibrio, Mycoplasma, Streptococcus, and unassigned OTUs in the families of Desulfobacteraceae and Xanthomonadaceae. For sesame seeds, the core microbiome included Aminivibrio, Chryseolina, Okibacterium, and unassigned OTUs in the family Flavobacteriaceae. The microbiomes of these seeds revealed that these products are dominated by environmental bacterial genera commonly isolated from soil, water, and plants; bacterial genera containing species known as commensal organisms were also identified. Understanding these microbiomes can aid in the risk assessment of these products by identifying food spoilage potential and community members which may co-enrich with foodborne bacterial pathogens.
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Affiliation(s)
- Megan Fay
- Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, Illinois, United States of America
| | - Joelle K. Salazar
- Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, Illinois, United States of America
| | - Padmini Ramachandran
- Division of Microbiology, U. S. Food and Drug Administration, College Park, Maryland, United States of America
| | - Diana Stewart
- Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, Illinois, United States of America
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Zuo W, Yu Y, Huang H. Making waves: Microbe-photocatalyst hybrids may provide new opportunities for treating heavy metal polluted wastewater. WATER RESEARCH 2021; 195:116984. [PMID: 33711746 DOI: 10.1016/j.watres.2021.116984] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/28/2020] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
Heavy metal contamination has received increasing attention as a growing worldwide environmental problem. Traditional remediation methods are mainly based on adsorption, precipitation and oxidation-reduction, which reduce the availability or toxicity of heavy metal ions. Microbe-photocatalyst hybrids (MPH), which behave as a semi-artificial photosynthetic system, integrate microbial cells with artificial photocatalysts for solar-to-chemical conversion. A few very recent studies indicate that MPH can be applied to treat organic contamination in water. Here, we propose a novel idea that MPH may also have great potential for solving heavy metal pollution. Heavy metals in wastewater could possibly be utilized to synthesize photocatalysts for MPH by microbial mineralization. Photo-induced electrons generated by photocatalysts in MPH can be transferred into microbial cells to promote intracellular enzymatic reductions, which allows heavy metal ions such as Cr6+ and Se4+ to be reduced and detoxified. Moreover, heavy metal ions like As3+ and Sb3+ can be used as sacrificial electron donors to maintain the continuous operation of the MPH, whereby these metal ions are simultaneously oxidized and detoxified. The excellent potential of MPH in the treatment of heavy metal-polluted wastewater is explained and a solution based on MPH is put forward as well as verified experimentally in this work. This solution can realize electron transfer between different metal ions to simultaneously remediate multiple heavy metal ions in wastewater. This finding may bring new hope for treating multiple heavy metal polluted wastewater in the future.
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Affiliation(s)
- Wenlu Zuo
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, People's Republic of China; School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, People's Republic of China
| | - Yadong Yu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, People's Republic of China.
| | - He Huang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, People's Republic of China; School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, People's Republic of China.
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11
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Identification and Metabolism of Naturally Prevailing Microorganisms in Zinc and Copper Mineral Processing. MINERALS 2021. [DOI: 10.3390/min11020156] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
It has only recently been discovered that naturally prevailing microorganisms have a notable role in flotation in addition to chemical process parameters and overall water quality. This study’s aim was to assess the prevailing microbial communities in relation to process chemistry in a zinc and copper mineral flotation plant. Due to the limitations of cultivation-based microbial methods that detect only a fraction of the total microbial diversity, DNA-based methods were utilised. However, it was discovered that the DNA extraction methods need to be improved for these environments with high mineral particle content. Microbial communities and metabolism were studied with quantitative PCR and amplicon sequencing of bacterial, archaeal and fungal marker genes and shotgun sequencing. Bacteria dominated the microbial communities, but in addition, both archaea and fungi were present. The predominant bacterial metabolism included versatile sulfur compound oxidation. Putative Thiovirga sp. dominated in the zinc plant and the water circuit samples, whereas Thiobacillus spp. dominated the copper plant. Halothiobacillus spp. were also an apparent part of the community in all samples. Nitrogen metabolism was more related to assimilatory than dissimilatory nitrate and nitrite oxidation/reduction reactions. Abundance of heavy metal resistance genes emphasized the adaptation and competitive edge of the core microbiome in these extreme conditions compared to microorganisms freshly entering the process.
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12
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Xia X, Wu S, Zhou Z, Wang G. Microbial Cd(II) and Cr(VI) resistance mechanisms and application in bioremediation. JOURNAL OF HAZARDOUS MATERIALS 2021; 401:123685. [PMID: 33113721 DOI: 10.1016/j.jhazmat.2020.123685] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 07/16/2020] [Accepted: 08/05/2020] [Indexed: 05/21/2023]
Abstract
The heavy metals cadmium (Cd) and chromium (Cr) are extensively used in industry and result in water and soil contamination. The highly toxic Cd(II) and Cr(VI) are the most common soluble forms of Cd and Cr, respectively. They enter the human body through the food chain and drinking water and then cause serious illnesses. Microorganisms can adsorb metals or transform Cd(II) and Cr(VI) into insoluble or less bioavailable forms, and such strategies are applicable in Cd and Cr bioremediation. This review focuses on the highlighting of novel achievements on microbial Cd(II) and Cr(VI) resistance mechanisms and their bioremediation applications. In addition, the knowledge gaps and research perspectives are also discussed in order to build a bridge between the theoretical breakthrough and the resolution of Cd(II) and Cr(VI) contamination problems.
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Affiliation(s)
- Xian Xia
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China; Hubei Key Laboratory of Edible Wild Plants Conservation & Utilization, Hubei Engineering Research Center of Special Wild Vegetables Breeding and Comprehensive Utilization Technology, National Experimental Teaching Demonstrating Center, College of Life Sciences, Hubei Normal University, Huangshi, 435002, PR China
| | - Shijuan Wu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Zijie Zhou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
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13
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Wang X, Hu K, Xu Q, Lu L, Liao S, Wang G. Immobilization of Cd Using Mixed Enterobacter and Comamonas Bacterial Reagents in Pot Experiments with Brassica rapa L. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:15731-15741. [PMID: 33236634 DOI: 10.1021/acs.est.0c03114] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Enterobacter sp. A11 and Comamonas sp. A23 were isolated and identified. Coculturing these two strains with Cd(II) led to the production of biofilm, H2S, and succinic acid (SA), and Cd(II) was adsorbed by cells and formed CdS precipitates. After centrifugation, 97% Cd(II) was removed from the coculture. Proteomic and metabolomic analyses of the cocultured bacteria revealed that H2S and SA production pathways, metal transportation, and TCA cycle were active under Cd(II) stress. In vitro addition of SA enhanced the production of H2S and biofilm formation and Cd(II) adsorption. Two-season greenhouse pot experiments with Brassica rapa L. were performed with and without the coculture bacteria. Compared with the control, the average Cd amounts of the two-season pot experiments of the aboveground plants were decreased by 71.3%, 62.8%, and 38.6%, and the nonbioavailable and immobilized Cd in the soils were increased by 211.8%, 213.4%, and 116.7%, for low-, medium-, and high- Cd-spiked soils, respectively. The two strains survived well in soil during plant growth using plate counting, quantitative real-time PCR, and metagenomics analysis. Our results indicate that the combination of Enterobacter and Comamonas strains with the production of H2S and biofilm are important effectors for the highly efficient immobilization of Cd.
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14
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Wang X, Li D, Gao P, Gu W, He X, Yang W, Tang W. Analysis of biosorption and biotransformation mechanism of Pseudomonas chengduensis strain MBR under Cd(II) stress from genomic perspective. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 198:110655. [PMID: 32361136 DOI: 10.1016/j.ecoenv.2020.110655] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 06/11/2023]
Abstract
Microbial treatment of heavy metal-polluted sites is considered an environmentally friendly bioremediation technology with high potential. This study shows that Pseudomonas chengduensis strain MBR, a bacterium that can potentially be applied in the treatment of heavy metal pollution, is most affected by Cd(II) stress at the beginning of its growth. Up to 100% of total Cd(II) adsorption occurs in the first 48 h after treatment of stationary phase cells with Cd(II). A biofilm forms on the cell surface, Cd(II) adsorbs, and is reduced to Cd (0) in the form of nanoscale particles. The genome of strain MBR was sequenced, annotated and analyzed. We identified various genes potentially related to cadmium resistance, transport and metabolism. Analysis of the strain MBR genome is helpful to explore the mechanism of Cd(II) resistance, and can provide new ideas for cadmium pollution control.
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Affiliation(s)
- Xu Wang
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu, 610041, China; College of Life Sciences, Sichuan University, Chengdu, 610064, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Daping Li
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu, 610041, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Ping Gao
- College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Wenzhi Gu
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu, 610041, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaohong He
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu, 610041, China
| | - Wenyi Yang
- College of Environmental Sciences, Sichuan Agricultural University, Chengdu, 611130, China
| | - Wenzhong Tang
- State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 10085, China
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15
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Wu S, Xia X, Wang D, Zhou Z, Wang G. Gene function and expression regulation of RuvRCAB in bacterial Cr(VI), As(III), Sb(III), and Cd(II) resistance. Appl Microbiol Biotechnol 2019; 103:2701-2713. [DOI: 10.1007/s00253-019-09666-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 12/24/2022]
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16
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Cantera S, Sánchez-Andrea I, Sadornil LJ, García-Encina PA, Stams AJM, Muñoz R. Novel haloalkaliphilic methanotrophic bacteria: An attempt for enhancing methane bio-refinery. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 231:1091-1099. [PMID: 30602233 DOI: 10.1016/j.jenvman.2018.11.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 10/14/2018] [Accepted: 11/05/2018] [Indexed: 06/09/2023]
Abstract
Methane bioconversion into products with a high market value, such as ectoine or hydroxyectoine, can be optimized via isolation of more efficient novel methanotrophic bacteria. The research here presented focused on the enrichment of methanotrophic consortia able to co-produce different ectoines during CH4 metabolism. Four different enrichments (Cow3, Slu3, Cow6 and Slu6) were carried out in basal media supplemented with 3 and 6% NaCl, and using methane as the sole carbon and energy source. The highest ectoine accumulation (∼20 mg ectoine g biomass-1) was recorded in the two consortia enriched at 6% NaCl (Cow6 and Slu6). Moreover, hydroxyectoine was detected for the first time using methane as a feedstock in Cow6 and Slu6 (∼5 mg g biomass-1). The majority of the haloalkaliphilic bacteria identified by 16S rRNA community profiling in both consortia have not been previously described as methanotrophs. From these enrichments, two novel strains (representing novel species) capable of using methane as the sole carbon and energy source were isolated: Alishewanella sp. strain RM1 and Halomonas sp. strain PGE1. Halomonas sp. strain PGE1 showed higher ectoine yields (70-92 mg ectoine g biomass-1) than those previously described for other methanotrophs under continuous cultivation mode (∼37-70 mg ectoine g biomass-1). The results here obtained highlight the potential of isolating novel methanotrophs in order to boost the competitiveness of industrial CH4-based ectoine production.
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Affiliation(s)
- Sara Cantera
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, Valladolid University, Dr. Mergelina, s/n, Valladolid, Spain
| | - Irene Sánchez-Andrea
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, the Netherlands
| | - Lidia J Sadornil
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, Valladolid University, Dr. Mergelina, s/n, Valladolid, Spain
| | - Pedro A García-Encina
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, Valladolid University, Dr. Mergelina, s/n, Valladolid, Spain
| | - Alfons J M Stams
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, the Netherlands
| | - Raúl Muñoz
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, Valladolid University, Dr. Mergelina, s/n, Valladolid, Spain.
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17
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Xia X, Li J, Zhou Z, Wang D, Huang J, Wang G. High-quality-draft genome sequence of the multiple heavy metal resistant bacterium Pseudaminobacter manganicus JH-7 T. Stand Genomic Sci 2018; 13:29. [PMID: 30386456 PMCID: PMC6203287 DOI: 10.1186/s40793-018-0330-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 09/28/2018] [Indexed: 01/01/2023] Open
Abstract
Pseudaminobacter manganicus JH-7T (= KCTC 52258T = CCTCC AB 2016107T) is a Gram-staining-negative, aerobic and non-motile strain that was isolated from a manganese mine. The strain JH-7T shows multiple heavy metal resistance and can effectively remove Mn2+ and Cd2+. In addition, it is able to produce exopolysaccharides (EPS), which may contribute to metal remove/adsorption. Thus, strain JH-7T shows a great potential in bioremediation of heavy metal-contaminated environment. In this study, we report the draft genomic sequence of P. manganicus JH-7T and compare it to related genomes. Strain JH-7T has a 4,842,937 bp genome size with a G + C content of 61.2%, containing 4504 protein-coding genes and 71 RNA genes. A large number of putative genes associated with heavy metal resistance and EPS synthesis are found in the genome.
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Affiliation(s)
- Xian Xia
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Jiahong Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Zijie Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Dan Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Jing Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
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18
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Comparison of performance and microbial communities in a bioelectrochemical system for simultaneous denitrification and chromium removal: Effects of pH. Process Biochem 2018. [DOI: 10.1016/j.procbio.2018.08.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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19
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Xia X, Wu S, Li L, Xu B, Wang G. The Cytochrome bd Complex Is Essential for Chromate and Sulfide Resistance and Is Regulated by a GbsR-Type Regulator, CydE, in Alishewanella Sp. WH16-1. Front Microbiol 2018; 9:1849. [PMID: 30147685 PMCID: PMC6096048 DOI: 10.3389/fmicb.2018.01849] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 07/24/2018] [Indexed: 01/17/2023] Open
Abstract
Sulfate-reducing bacteria are a group of microorganisms that use sulfate as an electron acceptor. These bacteria are useful in the bioremediation of heavy metal pollution since they can reduce/precipitate metals. Previously, we identified the Alishewanella strain WH16-1 from soil of a copper and iron mine and determined that it can reduce sulfate and chromate and that it was tolerant to many heavy metals. In this study, we investigated the chromate reduction mechanism of strain WH16-1 through Tn5 transposon mutagenesis. A cytochrome bd (cytbd) Tn5 mutant was generated (Δcytbd), and a detail analysis showed that the following: (1) gene cydE (coding for a GbsR-type regulator) was co-transcribed with the two subunits coding genes of the Cytochrome bd complex (Cytbd), namely, cydA and cydB, based on RT-PCR analysis, and similar gene arrangements were also found in other Alteromonadaceae family strains; (2) the chromate resistance level was dramatically decreased and chromate reduction efficiency also decreased in strain Δcytbd compared to the wild-type and a complemented strain (Δcytbd-C); (3) Cytbd could catalyze the decomposition of H2O2 according to the analyses of H2O2 decomposition ability, cellular H2O2 contents, H2O2 inhibition zone, and H2O2 sensitivity tests; (4) surprisingly, chromate was not an inducer of the expression of Cytbd, but sulfate induced expression of Cytbd, and sulfate/sulfide resistance levels were also decreased in the Δcytbd strain; (5) the addition of sulfate enhanced the chromate resistance level and reduction efficiency; (6) Cytbd expression was repressed by CydE and derepressed by sulfate based on an in vivo bacterial one hybrid system and in vitro EMSA tests; and (7) DNA footprinting and short-fragment EMSA tests revealed two binding sites of CydE in its promoter region. All these results showed that Cytbd is negatively regulated by CydE and derepressed by sulfate. In addition, Cytbd contributes to the resistance of sulfate and sulfide, and sulfide could be used as a reductant to reduce chromate. Moreover, Cytbd is essential to decompose H2O2 to decrease cellular oxidative stress. Thus, the regulation and function of Cytbd may explain why sulfate could enhance chromate reduction.
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Affiliation(s)
- Xian Xia
- State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shijuan Wu
- State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, China
| | - Liqiong Li
- State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, China
| | - Biao Xu
- State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, China
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20
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Xia X, Wu S, Li N, Wang D, Zheng S, Wang G. Novel bacterial selenite reductase CsrF responsible for Se(IV) and Cr(VI) reduction that produces nanoparticles in Alishewanella sp. WH16-1. JOURNAL OF HAZARDOUS MATERIALS 2018; 342:499-509. [PMID: 28881274 DOI: 10.1016/j.jhazmat.2017.08.051] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 07/25/2017] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
Alishewanella sp. WH16-1 is a facultative anaerobic bacterium isolated from mining soil. Under aerobic conditions, this bacterium efficiently reduces selenite and chromate. A flavoprotein showing 37% amino acid identity to E. coli chromate reductase ChrR was identified from the genome (named CsrF). Gene mutation and complementation along with heterologous expression revealed the ability of CsrF to reduce selenite and chromate in vivo. The purified CsrF was yellow and showed an absorption spectra similar to that of FMN. The molecular weight of CsrF was 23,906 for the monomer and 47,960 for the dimer. In vitro, CsrF catalyzes the reduction of Se(IV) and Cr(VI) using NAD(P)H as cofactors with optimal condition of pH 7.0 and temperature of 30-37°C. This enzyme also catalyze the reduction of sulfate and ferric iron but not arsenate and nitrate. Using NADPH as its electron donor, the Km for the reduction of Se(IV) and Cr(VI) was 204.1±27.91 and 250.6±23.46μmol/L, respectively. Site-directed mutagenesis showed that Arg13 and Gly113 were essential for the reduction of Se(IV) and Cr(VI). The products of the reduction of Se(IV) and Cr(VI) were Se(0)- and Cr(III)-nanoparticles, respectively. To our knowledge, CsrF is a novel and well-characterized bacterial aerobic selenite reductase.
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Affiliation(s)
- Xian Xia
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Shijuan Wu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Nuohan Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Dan Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Shixue Zheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
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21
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Zhang M, Huang F, Wang G, Liu X, Wen J, Zhang X, Huang Y, Xia Y. Geographic distribution of cadmium and its interaction with the microbial community in the Longjiang River: risk evaluation after a shocking pollution accident. Sci Rep 2017; 7:227. [PMID: 28331217 PMCID: PMC5427973 DOI: 10.1038/s41598-017-00280-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 02/17/2017] [Indexed: 12/14/2022] Open
Abstract
A shocking Longjiang River cadmium pollution accident occurred in 2012, the effects of which on microbial communities remain unclear. Alkaline precipitation technology was applied for remediation, but concerns rose about the stability of this technology. To understand the geographic distribution of cadmium and its correlation with microbes, in this study, 39 water samples and 39 sludge samples from this river and 2 soil samples from the nearby farmland were collected for chemical and microbial analyses. The Cd concentrations of all water samples were lower than 0.005 mg/L and reached the quality standards for Chinese surface water. A ranking of sludge samples based on Cd contents showed sewage outfall > dosing sites > farmland, all of which were higher than the quality standard for soil. Alkaline precipitation technology was effective for Cd precipitation. Cd was unstable; it was constantly dissolving and being released from the sludge. The Cd content of each phase was mainly influenced by the total Cd content. Over 40,000 effective sequences were detected in each sample, and a total of 59,833 OTUs and 1,273 genera were found using Illumina MiSeq sequencing. Two phyla and 39 genera were notably positively correlated with the Cd distribution, while the cases of 10 phyla and 6 genera were the opposite.
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Affiliation(s)
- MingJiang Zhang
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China
| | - FuKe Huang
- Institute of HeChi Scientific-Technical Information, No. 385 West Ring Road of HeChi City, GuangXi Zhuang Autonomous Region, 547000, China
| | - GuangYuan Wang
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China
| | - XingYu Liu
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China.
| | - JianKang Wen
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China
| | - XiaoSheng Zhang
- Institute of HeChi Scientific-Technical Information, No. 385 West Ring Road of HeChi City, GuangXi Zhuang Autonomous Region, 547000, China
| | - YaoSi Huang
- Institute of HeChi Scientific-Technical Information, No. 385 West Ring Road of HeChi City, GuangXi Zhuang Autonomous Region, 547000, China
| | - Yu Xia
- National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, Beijing, 100088, China
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