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Ye F, Duan L, Wang Z, Wang Y, Kou X, Wan F, Wang Y. Sediment grain size regulates the biogeochemical processes of nitrate in the riparian zone by influencing nutrient concentrations and microbial abundance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 954:176467. [PMID: 39326764 DOI: 10.1016/j.scitotenv.2024.176467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 09/10/2024] [Accepted: 09/20/2024] [Indexed: 09/28/2024]
Abstract
Riparian zones play a crucial role in reducing nitrate pollution in both terrestrial and aquatic environments. Complex deposition action and dynamic hydrological processes will change the grain size distribution of riparian sediments, affect the residence time of substances, and have a cascade effect on the biogeochemical process of nitrate nitrogen (NO3--N). However, simultaneous studies on NO3--N transformation and the potential drivers in riparian zones are still lacking, especially neglecting the effect of sediment grain size (SGS). To fill this knowledge gap, we first systematically identified and quantified NO3--N biogeochemical processes in the riparian zone by integrating molecular biotechnology, 15N stable isotope tracing, and microcosmic incubation experiments. We then evaluated the combined effects of environmental variables (including pH, dissolved organic carbon (DOC), oxidation reduction potential, SGS, etc.) on NO3--N transformation through Random Forest and Structural Equation Models. The results demonstrated that NO3--N underwent five microbial-mediated processes, with denitrification, dissimilatory nitrate reduction to ammonium (DNRA) dominated the NO3--N attenuation (69.4 % and 20.1 %, respectively), followed by anaerobic ammonia oxidation (anammox) and nitrate-dependent ferric oxidation (NDFO) (8.4 % and 2.1 %, respectively), while nitrification dominated the NO3--N production. SGS emerged as the most critical factor influencing NO3--N transformation (24.96 %, p < 0.01), followed by functional genes (nirS, nrfA) abundance, DOC, and ammonia concentrations (14.12 %, 16.40 %, 13.08 %, p < 0.01). SGS influenced NO3--N transformation by regulating microbial abundance and nutrient concentrations. RF predicted that a 5 % increase in the proportion of fine grains (diameter < 50 μm) may increase the NO3--N transformation rate by 3.8 %. This work highlights the significance of integrating machine learning and geochemical analysis for a comprehensive understanding of nitrate biogeochemical processes in riparian zones, contributing valuable references for future nitrogen management strategies.
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Affiliation(s)
- Fei Ye
- School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, China
| | - Lei Duan
- School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, China.
| | - Zhoufeng Wang
- School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, China
| | - Yike Wang
- School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, China
| | - Xiaomei Kou
- Power China Northwest Engineering Corporation Limited, Xi'an, Shaanxi 710065, China; Shaanxi Union Research Center of University and Enterprise for River and Lake Ecosystems Protection and Restoration, Xi'an, Shaanxi 710065, China
| | - Fan Wan
- Power China Northwest Engineering Corporation Limited, Xi'an, Shaanxi 710065, China; Shaanxi Union Research Center of University and Enterprise for River and Lake Ecosystems Protection and Restoration, Xi'an, Shaanxi 710065, China
| | - Yi Wang
- School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, China
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Cai L, Lu Y, Zhu H, Liu B, Li X, Jia T, Wang J, Wang X, Li P. Impact of bioelectricity on DNRA process and microbial community composition within cathodic biofilms in dual-chambered bioelectrode microbial fuel cell (MFC). BIORESOURCE TECHNOLOGY 2024; 400:130693. [PMID: 38608785 DOI: 10.1016/j.biortech.2024.130693] [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: 01/22/2024] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 04/14/2024]
Abstract
The synchronous bioelectricity generation and dissimilatory nitrate reduction to ammonium (DNRA) pathway in Klebsiella variicola C1 was investigated. The presence of bioelectricity facilitated cell growth on the anodic biofilms, consequently enhancing the nitrate removal efficiency decreasing total nitrogen levels and causing a negligible accumulation of NO2- in the supernatant. Genomic analysis revealed that K. variicola C1 possessed a complete DNRA pathway and largely annotated electron shuttles. The up-regulated expression of genes narG and nirB, encoding nitrite oxidoreductase and nitrite reductase respectively, was closely associated with increased extracellular electron transfer (EET). High-throughput sequencing analysis was employed to investigate the impact of bioelectricity on microbial community composition within cathodic biofilms. Results indicated that Halomonas, Marinobacter and Prolixibacteraceae were enriched at the cathode electrodes. In conclusion, the integration of a DNRA strain with MFC facilitated the efficient removal of wastewater containing high concentrations of NO3- and enabled the environmentally friendly recovery of NH4+.
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Affiliation(s)
- Luhan Cai
- School of Ocean Science and Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Yubiao Lu
- School of Ocean Science and Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Haiguang Zhu
- School of Ocean Science and Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Binxin Liu
- School of Ocean Science and Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Xinyi Li
- School of Ocean Science and Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Tianbo Jia
- School of Petrochemical Engineering and Environment, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Jianxin Wang
- School of Ocean Science and Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Xueting Wang
- School of Ocean Science and Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Peng Li
- School of Ocean Science and Technology, Zhejiang Ocean University, Zhoushan 316022, PR China.
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Deng D, He G, Ding B, Liu W, Yang Z, Ma L. Denitrification dominates dissimilatory nitrate reduction across global natural ecosystems. GLOBAL CHANGE BIOLOGY 2024; 30:e17256. [PMID: 38532549 DOI: 10.1111/gcb.17256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/04/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024]
Abstract
Denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA) are three competing processes of microbial nitrate reduction that determine the degree of ecosystem nitrogen (N) loss versus recycling. However, the global patterns and drivers of relative contributions of these N cycling processes to soil or sediment nitrate reduction remain unknown, limiting our understanding of the global N balance and management. Here, we compiled a global dataset of 1570 observations from a wide range of terrestrial and aquatic ecosystems. We found that denitrification contributed up to 66.1% of total nitrate reduction globally, being significantly greater in estuarine and coastal ecosystems. Anammox and DNRA could account for 12.7% and 21.2% of total nitrate reduction, respectively. The contribution of denitrification to nitrate reduction increased with longitude, while the contribution of anammox and DNRA decreased. The local environmental factors controlling the relative contributions of the three N cycling processes to nitrate reduction included the concentrations of soil organic carbon, ammonium, nitrate, and ferrous iron. Our results underline the dominant role of denitrification over anammox and DNRA in ecosystem nitrate transformation, which is crucial to improving the current global soil N cycle model and achieving sustainable N management.
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Affiliation(s)
- Danli Deng
- Hubei Field Observation and Scientific Research Stations for Water Ecosystem in Three Gorges Reservoir, China Three Gorges University, Yichang, China
- Hubei Key Laboratory of Wetland Evolution & Ecological Restoration, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
| | - Gang He
- Hubei Key Laboratory of Wetland Evolution & Ecological Restoration, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
| | - Bangjing Ding
- Hubei Key Laboratory of Wetland Evolution & Ecological Restoration, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
| | - Wenzhi Liu
- Hubei Key Laboratory of Wetland Evolution & Ecological Restoration, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
- Danjiangkou Wetland Ecosystem Field Scientific Observation and Research Station, Chinese Academy of Sciences & Hubei Province, Wuhan, China
| | - Zhengjian Yang
- Hubei Field Observation and Scientific Research Stations for Water Ecosystem in Three Gorges Reservoir, China Three Gorges University, Yichang, China
| | - Lin Ma
- Hubei Key Laboratory of Wetland Evolution & Ecological Restoration, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
- Danjiangkou Wetland Ecosystem Field Scientific Observation and Research Station, Chinese Academy of Sciences & Hubei Province, Wuhan, China
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Yan Y, Zhou J, Du C, Yang Q, Huang J, Wang Z, Xu J, Zhang M. Relationship between Nitrogen Dynamics and Key Microbial Nitrogen-Cycling Genes in an Intensive Freshwater Aquaculture Pond. Microorganisms 2024; 12:266. [PMID: 38399670 PMCID: PMC10892730 DOI: 10.3390/microorganisms12020266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
Intensive aquaculture in high-density hybrid snakehead [Channa maculata (♀) × Channa argus (♂)] fishponds can lead to toxic conditions for fish. This study investigated nitrogen migration and transformation in these fishponds during different cultivation periods. Using qPCR technology, we analyzed the abundance variation of nitrogen-cycling microorganisms in water and sediment to reveal the nitrogen metabolism characteristics of hybrid snakehead fishponds. The results showed that fish biomass significantly impacts suspended particulate matter (SPM) flux. At the sediment-water interface, inorganic nitrogen fluxes showed predominant NO3--N absorption by sediments and NH4+-N and NO2--N release, especially in later cultivation stages. Sediments were rich in nirS and AMX 16S rRNA genes (ranging from 4.04 × 109 to 1.01 × 1010 and 1.19 × 108 to 2.62 × 108 copies/g, respectively) with nirS-type denitrifiers potentially dominating the denitrification process. Ammonia-oxidizing bacteria (AOB) were found to dominate the ammonia oxidation process over ammonia-oxidizing archaea (AOA) in both water and sediment. Redundancy analysis revealed a positive correlation between SPM flux, Chlorophyll a (Chl-a), and denitrification genes in the water, and between nitrogen-cycling genes and NH4+/NO2- fluxes at the interface. These findings provide a scientific basis for nitrogen control in hybrid snakehead fishponds.
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Affiliation(s)
- Yifeng Yan
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.Y.); (J.Z.); (C.D.); (Q.Y.); (J.H.); (Z.W.)
| | - Junbo Zhou
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.Y.); (J.Z.); (C.D.); (Q.Y.); (J.H.); (Z.W.)
| | - Chenghao Du
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.Y.); (J.Z.); (C.D.); (Q.Y.); (J.H.); (Z.W.)
| | - Qian Yang
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.Y.); (J.Z.); (C.D.); (Q.Y.); (J.H.); (Z.W.)
| | - Jinhe Huang
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.Y.); (J.Z.); (C.D.); (Q.Y.); (J.H.); (Z.W.)
| | - Zhaolei Wang
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.Y.); (J.Z.); (C.D.); (Q.Y.); (J.H.); (Z.W.)
| | - Jun Xu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
| | - Min Zhang
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.Y.); (J.Z.); (C.D.); (Q.Y.); (J.H.); (Z.W.)
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She Y, Qi X, Xin X, He Y, Wang W, Li Z. Non-rhizosphere reinforces the contributions of Feammox and anammox to nitrogen loss than rhizosphere in riparian zones. ENVIRONMENTAL RESEARCH 2023; 239:117317. [PMID: 37806475 DOI: 10.1016/j.envres.2023.117317] [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: 09/02/2023] [Revised: 10/02/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
The emergence of anaerobic ammonium oxidation (anammox) coupled to iron reduction (named Feammox) refreshes the microbial pathways for nitrogen (N) loss. However, the ecological role of Feammox, compared with conventional denitrification and anammox, in microbial N attenuation in ecosystems remains unclear. Here, the specific contribution of Feammox to N loss and the underlying microbiome interactive characteristics in a riparian ecosystem were investigated through 15N isotope tracing and molecular analysis. Feammox was highlighted in the riparian interface soils and maximally contributed 14.2% of N loss. Denitrification remained the dominant contributor to N loss (68.0%-95.3%), followed by anammox (5.7%-19.1%) and Feammox (0-14.2%). The rates of Feammox and anammox significantly decreased in rhizosphere soils (0.15 ± 0.08 μg N g-1 d -1 for Feammox, 0.80 ± 0.39 μg N g-1 d -1 for anammox) compared with those in non-rhizosphere soils; however, the activities of denitrification remarkably increased in the rhizosphere (13.17 ± 3.71 μg N g-1 d -1). In rhizosphere soils, the competition between bioavailable organic matter (e.g., amino acids and carbohydrates) and ammonium for electron acceptor [i.e., Fe(III)] was the vital inducement for restricted Feammox, while the nitrite consumption boosted by heterotrophic denitrifiers was responsible for weakened anammox. The functional gene of autotrophic Acidimicrobiaceae bacterium A6, instead of heterotrophic Geobacteraceae spp., was significantly positively correlated with Feammox activity. Rare iron-reducing bacteria showed higher node degrees in the non-rhizosphere network than in the rhizosphere network. A syntrophic relationship was found between iron-reducing bacteria (e.g., Anaeromyxobacter, Geobacter) and iron-oxidizing bacteria (e.g., Sideroxydans) in the non-rhizosphere network and facilitated the Feammox pathway. This study provides an in-depth exploration of microbial driven N loss in a riparian ecosystem and introduces new insights into riparian management practices toward high-efficient N pollution alleviation.
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Affiliation(s)
- Yuecheng She
- State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, 210023, China; School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Xin Qi
- State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, 210023, China; School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Xiaodong Xin
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China
| | - Yanqing He
- State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, 210023, China; School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Wei Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, 210023, China; School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Zhengkui Li
- State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, 210023, China; School of the Environment, Nanjing University, Nanjing, 210023, China.
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Lin Y, Tang KW, Ye G, Yang P, Hu HW, Tong C, Zheng Y, Feng M, Deng M, He ZY, He JZ. Community assembly of comammox Nitrospira in coastal wetlands across southeastern China. Appl Environ Microbiol 2023; 89:e0080723. [PMID: 37671870 PMCID: PMC10537594 DOI: 10.1128/aem.00807-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 07/17/2023] [Indexed: 09/07/2023] Open
Abstract
Complete ammonia oxidizers (comammox Nitrospira) are ubiquitous in coastal wetland sediments and play an important role in nitrification. Our study examined the impact of habitat modifications on comammox Nitrospira communities in coastal wetland sediments across tropical and subtropical regions of southeastern China. Samples were collected from 21 coastal wetlands in five provinces where native mudflats were invaded by Spartina alterniflora and subsequently converted to aquaculture ponds. The results showed that comammox Nitrospira abundances were mainly influenced by sediment grain size rather than by habitat modifications. Compared to S. alterniflora marshes and native mudflats, aquaculture pond sediments had lower comammox Nitrospira diversity, lower clade A.1 abundance, and higher clade A.2 abundance. Sulfate concentration was the most important factor controlling the diversity of comammox Nitrospira. The response of comammox Nitrospira community to habitat change varied significantly by location, and environmental variables accounted for only 11.2% of the variations in community structure across all sites. In all three habitat types, dispersal limitation largely controlled the comammox Nitrospira community assembly process, indicating the stochastic nature of these sediment communities in coastal wetlands. IMPORTANCE Comammox Nitrospira have recently gained attention for their potential role in nitrification and nitrous oxide (N2O) emissions in soil and sediment. However, their distribution and assembly in impacted coastal wetland are poorly understood, particularly on a large spatial scale. Our study provides novel evidence that the effects of habitat modification on comammox Nitrospira communities are dependent on the location of the wetland. We also found that the assembly of comammox Nitrospira communities in coastal wetlands was mainly governed by stochastic processes. Nevertheless, sediment grain size and sulfate concentration were identified as key variables affecting comammox Nitrospira abundance and diversity in coastal sediments. These findings are significant as they advance our understanding of the environmental adaptation of comammox Nitrospira and how future landscape modifications may impact their abundance and diversity in coastal wetlands.
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Affiliation(s)
- Yongxin Lin
- Fujian Provincial Key Laboratory for Subtropical Resources and Environment, Fujian Normal University, Fuzhou, Fujian, China
| | - Kam W. Tang
- Department of Biosciences, Swansea University, Swansea, United Kingdom
| | - Guiping Ye
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, Minjiang University, Fuzhou, Fujian, China
- Technology Innovation Center for Monitoring and Restoration Engineering of Ecological Fragile Zone in Southeast China, Ministry of Natural Resources, Fuzhou, Fujian, China
| | - Ping Yang
- Fujian Provincial Key Laboratory for Subtropical Resources and Environment, Fujian Normal University, Fuzhou, Fujian, China
- Research Centre of Wetlands in Subtropical Region, Fujian Normal University, Fuzhou, Fujian, China
| | - Hang-Wei Hu
- School of Agriculture, Food and Ecosystem Sciences, Faculty of Science, The University of Melbourne, Melbourne, Victoria, Australia
| | - Chuan Tong
- Fujian Provincial Key Laboratory for Subtropical Resources and Environment, Fujian Normal University, Fuzhou, Fujian, China
- Research Centre of Wetlands in Subtropical Region, Fujian Normal University, Fuzhou, Fujian, China
| | - Yong Zheng
- Fujian Provincial Key Laboratory for Subtropical Resources and Environment, Fujian Normal University, Fuzhou, Fujian, China
| | - Mengmeng Feng
- Fujian Provincial Key Laboratory for Subtropical Resources and Environment, Fujian Normal University, Fuzhou, Fujian, China
| | - Milin Deng
- Fujian Provincial Key Laboratory for Subtropical Resources and Environment, Fujian Normal University, Fuzhou, Fujian, China
| | - Zi-Yang He
- Fujian Provincial Key Laboratory for Subtropical Resources and Environment, Fujian Normal University, Fuzhou, Fujian, China
| | - Ji-Zheng He
- Fujian Provincial Key Laboratory for Subtropical Resources and Environment, Fujian Normal University, Fuzhou, Fujian, China
- School of Agriculture, Food and Ecosystem Sciences, Faculty of Science, The University of Melbourne, Melbourne, Victoria, Australia
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Chen JY, Liu S, Deng WK, Niu SH, Liao XD, Xiang L, Xing SC. The effect of manure-borne doxycycline combined with different types of oversized microplastic contamination layers on carbon and nitrogen metabolism in sandy loam. JOURNAL OF HAZARDOUS MATERIALS 2023; 456:131612. [PMID: 37245359 DOI: 10.1016/j.jhazmat.2023.131612] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/28/2023] [Accepted: 05/09/2023] [Indexed: 05/30/2023]
Abstract
The different forms and properties of microplastics (MPs) have different effects on the elemental cycles in soil ecosystems, and this is further complicated when the soil contains antibiotics; meanwhile, oversized microplastic (OMP) in soil is always ignored in studies of environmental behavior. In the context of antibiotic action, the effects of OMP on soil carbon (C) and nitrogen (N) cycling have rarely been explored. In this study, we created four types of oversized microplastic (thick fibers, thin fibers, large debris, and small debris) composite doxycycline (DOX) contamination layers (5-10 cm) in sandy loam, hoping to reveal the effects on soil C and N cycling and potential microbial mechanisms when exposed to the combination of manure-borne DOX and different types of OMP from the perspective of metagenomics in the longitudinal soil layer (0-30 cm). The results showed that all different forms of OMP, when combined with DOX, reduced the soil C content in each layer, but only reduced the soil N content in the upper layer of the OMP contamination layer. The microbial structure of the surface soil (0-10 cm) was more noteworthy than that of the deeper soil (10-30 cm). The genera Chryseolinea and Ohtaekwangia were key microbes involved in C and N cycling in the surface layer and regulated carbon fixation in photosynthetic organisms (K00134), carbon fixation pathways in prokaryotes (K00031), methane metabolism (K11212 and K14941), assimilatory nitrate reduction (K00367), and denitrification (K00376 and K04561). The present study is the first to reveal the potential microbial mechanism of C and N cycling under OMP combined with DOX in different layers, mainly the OMP contamination layer and its upper layer, and the OMP shape plays an important role in this process.
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Affiliation(s)
- Jing-Yuan Chen
- College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China
| | - Shuo Liu
- College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China
| | - Wei-Kang Deng
- College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China
| | - Shi-Hua Niu
- College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China
| | - Xin-Di Liao
- College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, and Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry Agriculture, Guangzhou 510642, Guangdong, China; National-Local Joint Engineering Research Center for Livestock Breeding, Guangzhou 510642, Guangdong, China
| | - Lei Xiang
- Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education, Guangzhou 510632, Guangdong, China
| | - Si-Cheng Xing
- Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, and Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry Agriculture, Guangzhou 510642, Guangdong, China; National-Local Joint Engineering Research Center for Livestock Breeding, Guangzhou 510642, Guangdong, China.
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