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Zhang Y, Zhao SY, Zhang RH, Li BL, Li YY, Han H, Duan PF, Chen ZJ. Screening of plant growth-promoting rhizobacteria helps alleviate the joint toxicity of PVC+Cd pollution in sorghum plants. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 355:124201. [PMID: 38810675 DOI: 10.1016/j.envpol.2024.124201] [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: 04/03/2024] [Revised: 05/03/2024] [Accepted: 05/21/2024] [Indexed: 05/31/2024]
Abstract
Combined microplastic and heavy metal pollution (CM-HP) has become a popular research topic due to the ability of these pollutants to have complex interactions. Plant growth-promoting rhizobacteria (PGPR) are widely used to alleviate stress from heavy metal pollution in plants. However, the effects and mechanisms by which these bacteria interact under CM-HP have not been extensively studied. In this study, we isolated and screened PGPR from CM-HP soils and analyzed the effects of these PGPR on sorghum growth and Cd accumulation under combined PVC+Cd pollution through pot experiments. The results showed that the length and biomass of sorghum plants grown in PVC+Cd contaminated soil were significantly lower than those grown in soils contaminated with Cd alone, revealing an enhancement in toxicity when the two contaminants were mixed. Seven isolated and screened PGPR strains effectively alleviated stress due to PVC+Cd contamination, which resulted in a significant enhancement in sorghum biomass. PGPR mitigated the decrease in soil available potassium, available phosphorus and alkali-hydrolyzable nitrogen content caused by combined PVC+Cd pollution and increased the contents of these soil nutrients. Soil treatment with combined PVC+Cd pollution and PGPR inoculation can affect rhizosphere bacterial communities and change the composition of dominant populations, such as Proteobacteria, Firmicutes, and Actinobacteria. PICRUSt2 functional profile prediction revealed that combined PVC+Cd pollution and PGPR inoculation affected nitrogen fixation, nitrification, denitrification, organic phosphorus mineralization, inorganic phosphorus solubilization and the composition and abundance of genes related the N and P cycles. The Mantel test showed that functional strain abundance, the diversity index and N and P cycling-related genes were affected by test strain inoculation and were significant factors affecting sorghum growth, Cd content and accumulation. This study revealed that soil inoculation with isolated and screened PGPR can affect the soil inorganic nutrient content and bacterial community composition, thereby alleviating the stress caused by CM-HP and providing a theoretical basis and data support for the remediation of CM-HP.
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Affiliation(s)
- Yu Zhang
- Overseas Expertise Introduction Center for Discipline Innovation of Watershed Ecological Security in the Water Source Area of the Mid-line Project of South-to-North Water Diversion, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, 473061, China
| | - Si-Yu Zhao
- Overseas Expertise Introduction Center for Discipline Innovation of Watershed Ecological Security in the Water Source Area of the Mid-line Project of South-to-North Water Diversion, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, 473061, China
| | - Ruo-Han Zhang
- Overseas Expertise Introduction Center for Discipline Innovation of Watershed Ecological Security in the Water Source Area of the Mid-line Project of South-to-North Water Diversion, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, 473061, China
| | - B Larry Li
- Overseas Expertise Introduction Center for Discipline Innovation of Watershed Ecological Security in the Water Source Area of the Mid-line Project of South-to-North Water Diversion, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, 473061, China
| | - Yu-Ying Li
- Overseas Expertise Introduction Center for Discipline Innovation of Watershed Ecological Security in the Water Source Area of the Mid-line Project of South-to-North Water Diversion, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, 473061, China
| | - Hui Han
- Overseas Expertise Introduction Center for Discipline Innovation of Watershed Ecological Security in the Water Source Area of the Mid-line Project of South-to-North Water Diversion, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, 473061, China
| | - Peng-Fei Duan
- Overseas Expertise Introduction Center for Discipline Innovation of Watershed Ecological Security in the Water Source Area of the Mid-line Project of South-to-North Water Diversion, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, 473061, China
| | - Zhao-Jin Chen
- Overseas Expertise Introduction Center for Discipline Innovation of Watershed Ecological Security in the Water Source Area of the Mid-line Project of South-to-North Water Diversion, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, 473061, China.
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Wang B, Wang C, Hu Y. Sorption behavior of Pb(II) onto polyvinyl chloride microplastics affects the formation and ecological functions of microbial biofilms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 832:155026. [PMID: 35390363 DOI: 10.1016/j.scitotenv.2022.155026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 06/14/2023]
Abstract
Microplastics (MPs) are regarded as transport media for heavy metals in aquatic systems, whereas the effects of the heavy metal-enriched MPs on microbial biofilms are still unclear. In this study, Pb(II) sorption onto polyvinyl chloride (PVC) MPs and its effects on the formation and ecological functions of microbial biofilms were investigated. The results showed that the interaction between Pb(II) and PVC MPs was dominated by physisorption. The maximum sorption amount reached 1.25 mg/g. Afterward, microbial biofilms were exposed to the Pb(II)-enriched PVC particles. It is suggested that Pb(II)-enriched PVC exposure reduced productivities of polysaccharides and proteins in extracellular polymeric substances, which restricted the formation of microbial biofilms. Meanwhile, microbial community structure was reassembled accompanying the decline of capacities for nitrate and phosphate removal. Therefore, this study examines the ecological risk associated with the heavy metal-enriched MPs that can adversely affect microbial biofilms.
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Affiliation(s)
- Binliang Wang
- School of Life Science, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China
| | - Chufan Wang
- School of Life Science, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China
| | - Yiwei Hu
- School of Life Science, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China.
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Chen ZJ, Liu YQ, Li YY, Lin LA, Zheng BH, Ji MF, Li BL, Han XM. The Seasonal Patterns, Ecological Function and Assembly Processes of Bacterioplankton Communities in the Danjiangkou Reservoir, China. Front Microbiol 2022; 13:884765. [PMID: 35783417 PMCID: PMC9240478 DOI: 10.3389/fmicb.2022.884765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 05/24/2022] [Indexed: 11/13/2022] Open
Abstract
As the water source for the Middle Route Project of the South-to-North Water Diversion Project (MR-SNWD) of China, the Danjiangkou Reservoir (DJR) is in the process of ecosystem reassembly, but the composition, function, and assembly mechanisms of bacterioplankton communities are not yet clear. In this study, the composition, distribution characteristics and influencing factors of bacterioplankton communities were analyzed by high-throughput sequencing (HTS); PICRUSt2 was used to predict community function; a molecular ecological network was used to analyze bacterioplankton interactions; and the assembly process of bacterioplankton communities was estimated with a neutral model. The results indicated that the communities, function and interaction of bacterioplankton in the DJR had significant annual and seasonal variations and that the seasonal differences were greater than that the annual differences. Excessive nitrogen (N) and phosphorus (P) nutrients in the DJR are the most important factors affecting water quality in the reservoir, N and P nutrients are the main factors affecting bacterial communities. Season is the most important factor affecting bacterioplankton N and P cycle functions. Ecological network analysis indicated that the average clustering coefficient and average connectivity of the spring samples were lower than those of the autumn samples, while the number of modules for the spring samples was higher than that for the autumn samples. The neutral model explained 66.3%, 63.0%, 63.0%, and 70.9% of the bacterioplankton community variations in samples in the spring of 2018, the autumn of 2018, the spring of 2019, and the autumn of 2019, respectively. Stochastic processes dominate bacterioplankton community assembly in the DJR. This study revealed the composition, function, interaction, and assembly of bacterioplankton communities in the DJR, providing a reference for the protection of water quality and the ecological functions of DJR bacterioplankton.
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Affiliation(s)
- Zhao-Jin Chen
- International Joint Laboratory of Watershed Ecological Security and Collaborative Innovation Center of Water Security for Water Source Region of Middle Route Project of South-North Water Diversion in Henan Province, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, China
| | - Yong-Qi Liu
- International Joint Laboratory of Watershed Ecological Security and Collaborative Innovation Center of Water Security for Water Source Region of Middle Route Project of South-North Water Diversion in Henan Province, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, China
| | - Yu-Ying Li
- International Joint Laboratory of Watershed Ecological Security and Collaborative Innovation Center of Water Security for Water Source Region of Middle Route Project of South-North Water Diversion in Henan Province, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, China
- *Correspondence: Yu-Ying Li,
| | - Li-An Lin
- International Joint Laboratory of Watershed Ecological Security and Collaborative Innovation Center of Water Security for Water Source Region of Middle Route Project of South-North Water Diversion in Henan Province, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, China
| | - Bao-Hai Zheng
- International Joint Laboratory of Watershed Ecological Security and Collaborative Innovation Center of Water Security for Water Source Region of Middle Route Project of South-North Water Diversion in Henan Province, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, China
| | - Ming-Fei Ji
- International Joint Laboratory of Watershed Ecological Security and Collaborative Innovation Center of Water Security for Water Source Region of Middle Route Project of South-North Water Diversion in Henan Province, School of Water Resource and Environmental Engineering, Nanyang Normal University, Nanyang, China
| | - B. Larry Li
- Ecological Complexity and Modelling Laboratory, Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
| | - Xue-Mei Han
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou, China
- Xue-Mei Han,
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Sirichoat A, Lulitanond V, Faksri K. Analysis of bacterial and fungal communities in fermented fish (pla-ra) from Northeast Thailand. Arch Microbiol 2022; 204:302. [PMID: 35524014 DOI: 10.1007/s00203-022-02923-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 04/15/2022] [Indexed: 01/16/2023]
Abstract
Our aim was to explore the microbial community composition (bacteria and fungi) of fermented fish (pla-ra) from Northeast Thailand. We also made functional predictions concerning these microbial communities. The association between the microbiota and odor intensity was also analyzed. Fourteen samples of 1-year fermented fish samples derived from seven local markets in Khon Kaen, Northeast Thailand were used. The microbial community composition of each was investigated by sequencing the V1-V9 regions of the 16S rRNA gene (bacteria) and the ITS gene (fungi) using an Illumina MiSeq platform. Functional prediction analysis was conducted through Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) based on the use of the bacterial 16S rRNA gene sequences. The bacterial communities were rich, comprising 402 genera from 28 phyla, including such genera as Tetragenococcus, Staphylococcus, Virgibacillus, Lactobacillus and Lentibacillus. The fungal communities comprised 7 phyla and 60 genera, such as Heterobasidion, Densospora, Exophiala and Monascus. The bacterial community functional analysis revealed an association with six biological metabolic pathway categories (e.g., metabolism, genetic information processing, environmental information processing, cellular processes, organismal systems and human diseases) with 17 subfunctions, showing the richness of bacterial community functions. Odor-association analysis revealed that Brevibacterium, Brachybacterium and Chromohalobacter were more abundant in the weak-odor group, while Noviherbaspirillum was more abundant in the strong-odor group. This study provides a preliminary analysis of pla-ra microbial community structure and function in popular traditional Thai foods. Functional prediction analysis might be helpful to improve our knowledge of the microbiota in fermented fish.
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Affiliation(s)
- Auttawit Sirichoat
- Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
- Research and Diagnostic Center for Emerging Infectious Diseases (RCEID), Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Viraphong Lulitanond
- Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
- Research and Diagnostic Center for Emerging Infectious Diseases (RCEID), Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Kiatichai Faksri
- Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
- Research and Diagnostic Center for Emerging Infectious Diseases (RCEID), Khon Kaen University, Khon Kaen, 40002, Thailand.
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Chi Z, Zhu Y, Yin Y. Insight into SO 4(-II)- dependent anaerobic methane oxidation in landfill: Dual-substrates dynamics model, microbial community, function and metabolic pathway. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 141:115-124. [PMID: 35114562 DOI: 10.1016/j.wasman.2022.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/18/2021] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
In anaerobic landfill, SO42- could serve as electron receptor for methane oxidation. In theory, concentrations of both methane and SO42- should be related to methane oxidation rate. However, the dynamics process has yet to be discovered, and the understanding of metabolic pathways of the sulfate-dependent anaerobic methane oxidation (S-DAMO) process in landfill remains limited. In this study, S-DAMO dynamics was investigated by observing the CH4 oxidation rates under different CH4/ SO42-counter-gradients. The CH4-SO42- dual-substrate model based on MichaeliseMenten equation was got (maximum substrate degradation rate Vmax [22.9 ± 1.31] µmol/[kg·d], half-saturation constants [Formula: see text] , and [Formula: see text] ). High-throughput sequencing analysis indicated Methanobacterials, Methanosarcinales, and Soil Crenarchaeotic were the main functional microorganisms for S-DAMO in landfill. The metabolic pathway of S-DAMO was speculated as the reverse methanogenesis pathway through Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUST) analysis, while methanogenesis was the methyl nutrition way based on methanol. The enzymes related to the carbon and sulfur cycles and their relative abundances in the microcosms were analyzed to graph the methane metabolic pathway and the sulfur metabolic pathway. The findings provide important parameters for CH4 mitigation in landfills, and give a new insight for understanding S-DAMO metabolic pathway in landfill.
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Affiliation(s)
- Zifang Chi
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, PR China.
| | - Yuhuan Zhu
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, PR China
| | - Ying Yin
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, PR China
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Variation in archaeal and bacterial community profiles and their functional metabolic predictions under the influence of pure and mixed fertilizers in paddy soil. Saudi J Biol Sci 2021; 28:6077-6085. [PMID: 34764741 PMCID: PMC8568845 DOI: 10.1016/j.sjbs.2021.08.091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 08/26/2021] [Accepted: 08/29/2021] [Indexed: 11/23/2022] Open
Abstract
Impact of environmental perturbations i.e., nitrogen (N), phosphorus (P), potassium (K), and rice straw (Rs) on the dynamics of soil bacterial and archaeal communities are multifactor dependent and seeks a contemporary approach to study underlying mechanisms. The current study investigates the effect of pure and mixed fertilizers on soil physicochemical properties, the microbial community structure, and their functional metabolic predictions. It involved amendments with distinct combinations of N as C(H2N)2O, P and K as KH2PO4, K as KCl, and Rs in paddy soil microcosms with concentrations common in rice fields agriculture. Soil pH, electrical conductivity (EC), total carbon (TC), total nitrogen (TN), organic matter (OM), available K (AK), and total extractable P (TEP) were evaluated. To comprehend community variation and functional predictions, 16S rRNA-based high throughput sequencing (HTS) and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) were employed, respectively. Our findings showed enhanced community richness and diversity in all amendments compared to control. Proteobacteria, Actinobacteria, and Firmicutes were dominant bacterial phyla. Regarding relative abundance, Chloroflexi, Bacteroidetes, and Verrucomicrobia showed positive while Actinobacteria, Acidobacteria, and Gemmatimonadetes showed negative trends compared to controls. Thaumarchaeota and Euryarchaeota were dominant archaeal phyla and exhibited increasing and decreasing trends, respectively. The PICRUSt analysis indicated functional prediction more towards amino acid, carbohydrate, energy, and lipid metabolism while less towards others. Concerning energy metabolism, most and least responsive treatments were KP and controls, respectively. These outcomes enhanced our understanding regarding soil quality, fertilizer composition and application, and functional metabolomics of archaea and bacteria.
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Ahmed A, Khurshid A, Tang X, Wang J, Khan TU, Mao Y. Structural and Functional Impacts of Microbiota on Pyropia yezoensis and Surrounding Seawater in Cultivation Farms along Coastal Areas of the Yellow Sea. Microorganisms 2021; 9:microorganisms9061291. [PMID: 34204837 PMCID: PMC8231614 DOI: 10.3390/microorganisms9061291] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 12/24/2022] Open
Abstract
Pyropia yezoensis is the most important commercial edible red algae in China, carrying a variety of resident microbes at its surface. To understand microbiome diversity, community structure, interactions and functions with hosts in this regard, thalli and seawater sampleswere collected from Yantai and Rizhao cultivation farms in the Yellow Sea. The thalli and seawater samples (n = 12) were collected and studied using an Illumina NovaSeq 6000 platform and 16S ribosomal RNA (rRNA) gene sequencing, along with the consideration of environmental factors. Bacterial communities in association with P. yezoensis and surrounding seawater were predominated by Cyanobacteria, Proteobacteria, and Bacteroidetes. The variability of bacterial communities related to P. yezoensis and seawater were predominantly shaped by nitrate (NO3), ammonium (NH4), and temperature. Cluster analysis revealed a close relationship between thalli (RTH and YTH) and seawater (RSW and YSW) in terms of the residing bacterial communities, respectively. PICRUSt analysis revealed the presence of genes associated with amino acid transportation and metabolism, which explained the bacterial dependence on algal-provided nutrients. This study reveals that the diversity of microbiota for P. yezoensis is greatly influenced by abiotic factors and algal organic exudates which trigger chemical signaling and transportation responses from the bacterial community, which in turn activates genes to metabolize subsequent substrates.
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Affiliation(s)
- Arsalan Ahmed
- Key Laboratory of Marine Genetics and Breeding (Ministry of Education), College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (A.A.); (A.K.); (X.T.); (J.W.); (T.U.K.)
| | - Anam Khurshid
- Key Laboratory of Marine Genetics and Breeding (Ministry of Education), College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (A.A.); (A.K.); (X.T.); (J.W.); (T.U.K.)
| | - Xianghai Tang
- Key Laboratory of Marine Genetics and Breeding (Ministry of Education), College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (A.A.); (A.K.); (X.T.); (J.W.); (T.U.K.)
| | - Junhao Wang
- Key Laboratory of Marine Genetics and Breeding (Ministry of Education), College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (A.A.); (A.K.); (X.T.); (J.W.); (T.U.K.)
| | - Tehsin Ullah Khan
- Key Laboratory of Marine Genetics and Breeding (Ministry of Education), College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (A.A.); (A.K.); (X.T.); (J.W.); (T.U.K.)
| | - Yunxiang Mao
- Key Laboratory of Marine Genetics and Breeding (Ministry of Education), College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (A.A.); (A.K.); (X.T.); (J.W.); (T.U.K.)
- Key Laboratory of Utilization and Conservation of Tropical Marine Bioresource (Ministry of Education), College of Fisheries and Life Science, Hainan Tropical Ocean University, Sanya 572022, China
- Correspondence:
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Jia R, Wang K, Li L, Qu Z, Shen W, Qu D. Abundance and community succession of nitrogen-fixing bacteria in ferrihydrite enriched cultures of paddy soils is closely related to Fe(III)-reduction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137633. [PMID: 32146407 DOI: 10.1016/j.scitotenv.2020.137633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 02/24/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
In flooded paddy soils, some metal reducers are also capable of nitrogen (N) fixation, which is essential in ensuring a reliable N-supply for rice growth. Microbial iron [Fe(III)] reduction is an important biogeochemical process that can be stimulated by ferrihydrite amendment to paddy soil. Therefore, this study aimed to investigate the abundance and succession of the N2-fixing bacterial community in ferrihydrite enriched paddy soils collected from Hunan (HN) and Sichuan (SC) provinces, China. The relationship between the N2-fixing bacterial community and Fe(III) reduction was also assessed. When compared with the control treatment, ferrihydrite enrichment significantly enhanced nitrogenase (nifH) gene abundance by 8.05 × 105 to 4.45 × 106 copies g-1 soil during the 40-day flooding of HN soil, while nifH gene abundance in SC soil was remarkably increased by 5.90 × 107 to 9.56 × 107 copies g-1 soil during day 1 to 5 in response to ferrihydrite amendment. The relative abundance of N2-fixing bacteria peaked on day 5 (21.5% in HN soil and 5.4% in SC soil) and gradually decreased to a stable abundance after day 20. Remarkable increases in relative abundance of N2-fixing bacteria during the first 10 days of flooding were detected in both soils with ferrihydrite enrichment, whereas little difference was found after day 10 of flooding. During the early stage of flooding, the Shannon and Simpson indexes of N2-fixing bacteria with ferrihydrite enrichment were significantly decreased, and the community structure changed greatly. Most N2-fixing bacteria in ferrihydrite enriched paddy soils were phylogenetically related to the order Clostridiales, with some of those potentially capable of Fe(III) reduction. The community succession of N2-fixing bacteria closely correlated with Fe(III) reduction. Thus, improving N2-fixation via stimulation of Fe(III) reduction might aid in the reduction of N-fertilizer application to paddy field.
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Affiliation(s)
- Rong Jia
- Key Laboratory of Land Resources Evaluation and Monitoring in Southwest China, Ministry of Education, Sichuan Normal University, Chengdu, Sichuan Province 610066, PR China; College of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi Province 712100, PR China
| | - Kun Wang
- College of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi Province 712100, PR China
| | - Lina Li
- College of Resources and Environment, Shanxi Agricultural University, Jinzhong, Shanxi Province 030801, PR China
| | - Zhi Qu
- State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, Shaanxi Province 710048, PR China
| | - Weishou Shen
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, PR China
| | - Dong Qu
- State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest A&F University, Yangling, Shaanxi Province, PR China.
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Xia Q, Liu X, Gao Z, Wang J, Yang Z. Responses of rhizosphere soil bacteria to 2-year tillage rotation treatments during fallow period in semiarid southeastern Loess Plateau. PeerJ 2020; 8:e8853. [PMID: 32411509 PMCID: PMC7207221 DOI: 10.7717/peerj.8853] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 03/04/2020] [Indexed: 02/01/2023] Open
Abstract
Background Soil compaction can be mitigated by deep tillage and subsoiling practices following a long period of no-tillage. Fallow tillage rotation methods are frequently used to improve water availability in the soils of the southeastern Loess Plateau region of China. Rhizosphere soil bacteria are ecologically important for the transformation of matter and energy in the plant root system and can be influenced by tillage rotation treatments. However, the effect of tillage rotations on the bacterial community and structure of rhizosphere soil is not well understood. Methods A two-year field experiment was conducted with four tillage rotation treatments, including subsoil–subsoil (SS-SS), subsoil–deep tillage (SS-DT), deep tillage–deep tillage (DT-DT), and the control treatment of no-tillage–no-tillage (NT-NT). Our study was conducted during wheat’s fallow period to investigate the abundance, diversity, and functions of rhizosphere soil bacteria using high-throughput sequencing technology. Results Our results showed that tillage rotation methods significantly influenced the bacterial diversity and composition of the rhizosphere soil in the plough layer (20–40 cm depth) by altering the moisture content of the soil. The metabolism, environmental information processing, and genetic information processing of the bacteria in the rhizosphere soil were affected. The most abundant phyla across all samples were Proteobacteria, Actinobacteria, Acidobacteria, Planctomycetes, Bacteroidetes, Gemmatimonadetes, Frimicutes, Chloroflexi, Nitrospirae, and Verrucomicrobia, which are classic bacterial decomposers in soil. The bacterial diversity and composition was similar for treatments causing higher soil perturbation (SS-DT and DT-DT), which disrupted the balance between aerobic and anaerobic bacteria. The less disruptive tillage methods (SS-SS and NT-NT), preserved the integrity of the soil bacteria. However, the NT-NT treatment may have led to soil compaction, particularly in the 20–40 cm layer. These results suggested that SS-SS was the most effective tillage rotation practice to accumulate soil moisture, maintain the balance between aerobic and anaerobic bacteria, and to enhance the metabolic capacity of rhizosphere soil bacteria. This method may have a significant impact on the sustainable development and farming practices of dryland agriculture.
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Affiliation(s)
- Qing Xia
- College of Agriculture, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Xiaoli Liu
- College of Agriculture, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Zhiqiang Gao
- College of Agriculture, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Jianming Wang
- College of Agriculture, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Zhenping Yang
- College of Agriculture, Shanxi Agricultural University, Taigu, Shanxi, China
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Miscanthus cultivation shapes rhizosphere microbial community structure and function as assessed by Illumina MiSeq sequencing combined with PICRUSt and FUNGUIld analyses. Arch Microbiol 2020; 202:1157-1171. [PMID: 32067064 DOI: 10.1007/s00203-020-01830-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/31/2020] [Accepted: 02/04/2020] [Indexed: 12/11/2022]
Abstract
Soil microbes play important roles in plant growth and in the biogeochemical cycling of earth's elements. However, the structure and functions of the microbial community associated with the growth of second-generation energy crops, such as Miscanthus, remain unclear. Thus, in this study, the composition and function of the bacterial and fungal communities associated with Miscanthus cultivation were analyzed by MiSeq sequencing combined with PICRUSt and FUNGUIld analyses. The results of community composition and diversity index analyses showed that Miscanthus cultivation significantly altered the bacterial and fungal community composition and reduced bacterial and fungal diversity. In addition, Miscanthus cultivation increased the soil organic matter (SOM) and total nitrogen (TN) contents. The correlation analysis between microbial community composition and environmental factors indicated that SOM and TN were the most important factors affecting bacterial and fungal communities. Miscanthus cultivation could enrich the abundances of Pseudomonas, Rhizobium, Luteibacter, Bradyrhizobium, Phenylobacterium and other common plant-promoting bacteria, while also increasing Cladophialophora, Hymenula, Magnaporthe, Mariannaea, etc., which predicted corresponded to the saprotrophic, plant pathogenic, and pathotrophic trophic modes. The PICRUSt predictive analysis indicated that Miscanthus cultivation altered the metabolic capabilities of bacterial communities, including the metabolism of carbon, nitrogen, and phosphorus cycle. In addition, FUNGUIld analysis indicated that Miscanthus cultivation altered the fungal trophic mode. The effects of Miscanthus on the communities and function of bacteria and fungi varied among Miscanthus species. Miscanthus specie Xiangdi NO 1 had the greatest impact on soil bacterial and fungal communities, whereas Miscanthus specie Wujiemang NO 1 had the greatest impact on soil bacteria and fungi functions. The results of this study provide a reference for the composition and function of microbial communities during the growth of Miscanthus.
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Rhizosphere Bacterial Community Structure and Predicted Functional Analysis in the Water-Level Fluctuation Zone of the Danjiangkou Reservoir in China During the Dry Period. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17041266. [PMID: 32079120 PMCID: PMC7068437 DOI: 10.3390/ijerph17041266] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/13/2020] [Accepted: 02/14/2020] [Indexed: 12/24/2022]
Abstract
The water-level fluctuation zone (WLFZ) is a transitional zone between terrestrial and aquatic ecosystems. Plant communities that are constructed artificially in the WLFZ can absorb and retain nutrients such as nitrogen (N) and phosphorus (P). However, the microbial community composition and function associated with this process have not been elucidated. In this study, four artificially constructed plant communities, including those of herbs (Cynodon dactylon and Chrysopogon zizanioides), trees (Metasequoia glyptostroboides), and shrubs (Salix matsudana) from the newly formed WLFZ of the Danjiangkou Reservoir were evaluated. The bacterial community compositions were analyzed by 16S rRNA gene sequencing using a MiSeq platform, and the functions of these communities were assessed via Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis. The results showed that the bacterial communities primarily comprised 362 genera from 24 phyla, such as Proteobacteria, Acidobacteria, Actinobacteria, and Gemmatimonadetes, showing the richness of the community composition. Planting altered the bacterial community composition, with varying effects observed among the different plant types. The bacterial community functional analysis revealed that these bacteria were primarily associated with six biological metabolic pathway categories (e.g., metabolism, genetic information processing, and environmental information processing) with 34 subfunctions, showing the richness of community functions. The planting of M. glyptostroboides, S. matsudana, and C. dactylon improved the metabolic capabilities of bacterial communities. N- and P-cycling gene analysis showed that planting altered the N- and P-cycling metabolic capacities of soil bacteria. The overall N- and P-metabolic capacity was highly similar between C. dactylon and C. zizanioides samples and between S. matsudana and M. glyptostroboides samples. The results of this study provide a preliminary analysis of soil bacterial community structure and function in the WLFZ of the Danjiangkou Reservoir and provides a reference for vegetation construction in this zone.
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Zhou J, You X, Niu B, Yang X, Gong L, Zhou Y, Wang J, Zhang H. Enhancement of methanogenic activity in anaerobic digestion of high solids sludge by nano zero-valent iron. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 703:135532. [PMID: 31759718 DOI: 10.1016/j.scitotenv.2019.135532] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/13/2019] [Accepted: 11/13/2019] [Indexed: 06/10/2023]
Abstract
This study evaluated the effects of nano zero-valent iron (NZVI, 50 nm) on anaerobic digestion of high solids sludge (10 ± 0.5%). Compared to the blank group without NZVI, the group with NZVI at all levels (10, 20 and 30 mM) played a driving role in methane production. The maximal methane production was increased by 37.5% in the group of 30 mM NZVI. The dynamic changes of hydrogen content and VFAs showed that rapid hydrogen evolutional corrosion of NZVI made lower hydrogen partial pressure in the later stage, which was more conducive to conversion of propionic acid. The microscopic analysis indicated that NZVI could flocculate and adsorb on the extracellular polymeric substances (EPS) around the anaerobic microorganisms, protecting most active microbial cell membrane from contact damage. On the other hand, some decaying microbial cells membrane could be destroyed by NZVI and intracellular substances would be released due to the reduction of EPS.
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Affiliation(s)
- Jun Zhou
- College of Environmental and Safety Engineering, Qingdao University of Science and Technology, 53, Zhengzhou Road, Qingdao, Shandong Province 266042, PR China
| | - Xiaogang You
- College of Environmental and Safety Engineering, Qingdao University of Science and Technology, 53, Zhengzhou Road, Qingdao, Shandong Province 266042, PR China
| | - Baowei Niu
- College of Environmental and Safety Engineering, Qingdao University of Science and Technology, 53, Zhengzhou Road, Qingdao, Shandong Province 266042, PR China
| | - Xiaoqi Yang
- College of Environmental and Safety Engineering, Qingdao University of Science and Technology, 53, Zhengzhou Road, Qingdao, Shandong Province 266042, PR China
| | - Lei Gong
- College of Environmental and Safety Engineering, Qingdao University of Science and Technology, 53, Zhengzhou Road, Qingdao, Shandong Province 266042, PR China.
| | - Ying Zhou
- College of Environmental and Safety Engineering, Qingdao University of Science and Technology, 53, Zhengzhou Road, Qingdao, Shandong Province 266042, PR China
| | - Jin Wang
- College of Environmental and Safety Engineering, Qingdao University of Science and Technology, 53, Zhengzhou Road, Qingdao, Shandong Province 266042, PR China
| | - Haonan Zhang
- College of Environmental and Safety Engineering, Qingdao University of Science and Technology, 53, Zhengzhou Road, Qingdao, Shandong Province 266042, PR China
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