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Fortune J, van de Kamp J, Holmes B, Bodrossy L, Gibb K, Kaestli M. Dynamics of nitrogen genes in intertidal sediments of Darwin Harbour and their connection to N-biogeochemistry. MARINE ENVIRONMENTAL RESEARCH 2024; 198:106500. [PMID: 38626627 DOI: 10.1016/j.marenvres.2024.106500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/29/2024] [Accepted: 04/08/2024] [Indexed: 04/18/2024]
Abstract
Microbial mediated nitrogen (N) transformation is subject to multiple controlling factors such as prevailing physical and chemical conditions, and little is known about these processes in sediments of wet-dry tropical macrotidal systems such as Darwin Harbour in North Australia. To understand key transformations, we assessed the association between the relative abundance of nitrogen cycling genes with trophic status, sediment partition and benthic nitrogen fluxes in Darwin Harbour. We analysed nitrogen cycling gene abundance using a functional gene microarray and quantitative PCRs targeting the denitrification gene (nosZ) and archaeal ammonia oxidation (AOA.1). We found a significant negative correlation between archaeal ammonia oxidation and silicate flux (P = 0.004), an indicator for diatom and benthic microalgal activity. It is suggested that the degradation of the diatomaceous organic matter generates localised anoxic conditions and inhibition of nitrification. Abundance of the nosZ gene was negatively correlated with nutrient load. The lowest nosZ gene levels were in hyper-eutrophic tidal creeks with anoxic conditions and increased levels of sulphide limiting the coupling of nitrification-denitrification (P = 0.016). Significantly higher levels of nosZ genes were measured in the surface (top 2 cm) compared to bulk sediment (top 10 cm) and there was a positive association with di-nitrogen flux (N2) in surface (P = 0.024) but not bulk sediment. This suggests that denitrifiers are most active in surficial sediment at the sediment-water interface. Elevated levels of nosZ genes also occurred in the sediments of tidal creek mouths and mudflats with these depositional zones combining the diffuse and seaward supply of nitrogen and carbon supporting denitrifiers. N-cycle molecular assays using surface sediments show promise as a rapid monitoring technique for impact assessment and measuring ecosystem function. This is particularly pertinent for tropical macrotidal systems where systematic monitoring is sparse and in many cases challenged by climatic extremes and remoteness.
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Affiliation(s)
- Julia Fortune
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia; Department of Environment, Parks and Water Security, Northern Territory Government, Australia.
| | | | | | | | - Karen Gibb
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Mirjam Kaestli
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia
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Huang S, Kong Y, Chen Y, Huang X, Ma P, Liu X. Microbial denitrification characteristics of typical decentralized wastewater treatment processes based on 16S rRNA sequencing. Front Microbiol 2023; 14:1242506. [PMID: 37779708 PMCID: PMC10537219 DOI: 10.3389/fmicb.2023.1242506] [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: 06/19/2023] [Accepted: 09/04/2023] [Indexed: 10/03/2023] Open
Abstract
Despite the widespread application of decentralized wastewater treatment (WWT) facilities in China, relatively few research has used the multi-media biological filter (MMBF) facilities to investigate the microorganism characteristics. This study utilizes 16S rRNA high-throughput sequencing (HTS) technology to examine the microbial biodiversity of a representative wastewater treatment (WWT) system in an expressway service area. The pathways of nitrogen removal along the treatment route were analyzed in conjunction with water quality monitoring. The distribution and composition of microbial flora in the samples were examined, and the dominant flora were identified using LEfSe analysis. The FAPROTAX methodology was employed to investigate the relative abundance of genes associated with the nitrogen cycle and to discern the presence of functional genes involved in nitrogen metabolism. On average, the method has a high level of efficiency in removing COD, TN, NH3-N, and TP from the effluent. The analysis of the microbial community identified a total of 40 phyla, 111 classes, 143 orders, 263 families, and 419 genera. The phyla that were predominantly observed include Proteobacteria, Acidobacteria, Chloroflexi, Actinobacteria, Nitrospirae, Bacteroidetes. The results show that the system has achieved high performance in nitrogen removal, the abundance of nitrification genes is significantly higher than that of other nitrogen cycle genes such as denitrification, and there are six nitrogen metabolism pathways, primarily nitrification, among which Nitrospirae and Nitrospira are the core differentiated flora that can adapt to low temperature conditions and participate in nitrification, and are the dominant nitrogen removal flora in cold regions. This work aims to comprehensively investigate the diversity and functional properties of the bacterial community in decentralized WWT processes.
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Affiliation(s)
- Shanqian Huang
- Center of Environment Protection, China Academy of Transportation Sciences, Beijing, China
| | - Yaping Kong
- Center of Environment Protection, China Academy of Transportation Sciences, Beijing, China
| | - Yao Chen
- Center of Environment Protection, China Academy of Transportation Sciences, Beijing, China
| | - Xuewen Huang
- Anhui Transportation Holding Group CO., LTD., Hefei, China
| | - Pengfei Ma
- Qinghai Expressway Maintenance Service CO., LTD., Xining, China
| | - Xuexin Liu
- Center of Environment Protection, China Academy of Transportation Sciences, Beijing, China
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Wang Y, Cao X, Yu H, Xu Y, Peng J, Qu J. Nitrate with enriched heavy oxygen isotope linked to changes in nitrogen source and transformation as groundwater table rises. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131527. [PMID: 37163892 DOI: 10.1016/j.jhazmat.2023.131527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 04/19/2023] [Accepted: 04/26/2023] [Indexed: 05/12/2023]
Abstract
Nitrate is a significant constituent of the total nitrogen pool in shallow aquifers and poses an escalating threat to groundwater resources, making it crucial to comprehend the source, conversion, and elimination of nitrogen using appropriate techniques. Although dual-isotope dynamics in nitrate have been widely used, uncertainties remain regarding the asynchronously temporal changes in δ18O-NO3- and δ15N-NO3- observed in hypoxic aquifers. This study aimed to investigate changes in nitrogen sources and transformations using temporal changes in field-based NO3- isotopic composition, hydro-chemical variables, and environmental DNA profiling, as the groundwater table varied. The results showed that the larger enrichment in δ18O-NO3- (+13‰) compared with δ15N-NO3- (-2‰) on average during groundwater table rise was due to a combination of factors, including high 18O-based atmospheric N deposition, canopies nitrification, and soil nitrification transported vertically by rainfalls, and 18O-enriched O2 produced through microbial and root respiration within denitrification. The strong association between functional gene abundance and nitrogen-related indicators suggests that anammox was actively processed with nitrification but in small bacterial population during groundwater table rise. Furthermore, bacterial species associated with nitrogen-associated gradients provided insight into subsurface nitrogen transformation, with Burkholderiaceae species and Pseudorhodobacter potentially serving as bioindicators of denitrification, while Candidatus Nitrotogn represents soil nitrification. Fluctuating groundwater tables can cause shifts in hydro-chemical and isotopic composition, which in turn can indicate changes in nitrogen sources and transformations. These changes can be used to improve input sources for mixture models and aid in microbial remediation of nitrate.
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Affiliation(s)
- Yajun Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaofeng Cao
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Hongwei Yu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yan Xu
- College of Marine Science and Technology, China University of Geosciences, Wuhan 430074, China
| | - Jianfeng Peng
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiuhui Qu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Zhang K, Zhang Y, Deng M, Wang P, Yue X, Wang P, Li W. Monthly dynamics of microbial communities and variation of nitrogen-cycling genes in an industrial-scale expanded granular sludge bed reactor. Front Microbiol 2023; 14:1125709. [PMID: 36876106 PMCID: PMC9978346 DOI: 10.3389/fmicb.2023.1125709] [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: 12/16/2022] [Accepted: 01/18/2023] [Indexed: 02/18/2023] Open
Abstract
Introduction The expanded granular sludge bed (EGSB) is a major form of anaerobic digestion system during wastewater treatment. Yet, the dynamics of microbial and viral communities and members functioning in nitrogen cycling along with monthly changing physicochemical properties have not been well elucidated. Methods Here, by collecting the anaerobic activated sludge samples from a continuously operating industrial-scale EGSB reactor, we conducted 16S rRNA gene amplicon sequencing and metagenome sequencing to reveal the microbial community structure and variation with the ever-changing physicochemical properties along within a year. Results We observed a clear monthly variation of microbial community structures, while COD, the ratio of volatile suspended solids (VSS) to total suspended solids (TSS) (VSS/TSS ratio), and temperature were predominant factors in shaping community dissimilarities examined by generalized boosted regression modeling (GBM) analysis. Meanwhile, a significant correlation was found between the changing physicochemical properties and microbial communities (p <0.05). The alpha diversity (Chao1 and Shannon) was significantly higher (p <0.05) in both winter (December, January, and February) and autumn (September, October, and November) with higher organic loading rate (OLR), higher VSS/TSS ratio, and lower temperature, resulting higher biogas production and nutrition removal efficiency. Further, 18 key genes covering nitrate reduction, denitrification, nitrification, and nitrogen fixation pathways were discovered, the total abundance of which was significantly associated with the changing environmental factors (p <0.05). Among these pathways, the dissimilatory nitrate reduction to ammonia (DNRA) and denitrification had the higher abundance contributed by the top highly abundant genes narGH, nrfABCDH, and hcp. The COD, OLR, and temperature were primary factors in affecting DNRA and denitrification by GBM evaluation. Moreover, by metagenome binning, we found the DNRA populations mainly belonged to Proteobacteria, Planctomycetota, and Nitrospirae, while the denitrifying bacteria with complete denitrification performance were all Proteobacteria. Besides, we detected 3,360 non-redundant viral sequences with great novelty, in which Siphoviridae, Podoviridae, and Myoviridae were dominant viral families. Interestingly, viral communities likewise depicted clear monthly variation and had significant associations with the recovered populations (p <0.05). Discussion Our work highlights the monthly variation of microbial and viral communities during the continuous operation of EGSB affected by the predominant changing COD, OLR, and temperature, while DNRA and denitrification pathways dominated in this anaerobic system. The results also provide a theoretical basis for the optimization of the engineered system.
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Affiliation(s)
- Kun Zhang
- School of Eco-environment Technology, Guangdong Industry Polytechnic, Guangzhou, China
| | - Yanling Zhang
- School of Mechanics and Construction Engineering, Jinan University, Guangzhou, China
| | - Maocheng Deng
- School of Food and Bioengineering, Guangdong Industry Polytechnic, Guangzhou, China
| | - Pengcheng Wang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, China.,China National Electric Apparatus Research Institute Co., Ltd., Guangzhou, China
| | - Xiu Yue
- School of Eco-environment Technology, Guangdong Industry Polytechnic, Guangzhou, China
| | - Pandeng Wang
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Wenjun Li
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
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Yuan H, Liu Q, Yu Y. Dynamic changes of serum cytokines in acute paraquat poisoning and changes in patients' immune function. IET Syst Biol 2022; 16:132-143. [PMID: 35761476 PMCID: PMC9290778 DOI: 10.1049/syb2.12045] [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: 11/29/2021] [Revised: 03/23/2022] [Accepted: 05/31/2022] [Indexed: 11/20/2022] Open
Abstract
Acute paraquat poisoning is due to the extremely severe toxicity of paraquat. After paraquat enters the human body, it will cause rapid changes in the human body system. Since paraquat poisoning will quickly invade the organs of the whole body, it may cause damage to the functions of multiple organs in the poisoned patient. The liver organ is the most important detoxification site for the human body, so the damage to the liver of the patient is more obvious. This article discovers and observes the structure of paraquat and the dynamic changes of serum cytokines in patients with paraquat poisoning through the clinical phenomenon of paraquat poisoning, and the related changes of human serum cells after the subjects took paraquat and the changes of cell dynamic factors after different doses of paraquat entered the human body were analysed. At the same time, the changes in the immune function of the body of different groups of people were also observed. The experimental results in this article show that according to the intake of paraquat, the severity of poisoning patients will be mild, moderate, severe and outbreak poisoning. Among them, the dose for adults who cannot be treated for prognosis is 10 ml.
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Affiliation(s)
- Huimin Yuan
- Emergency Department, Harrison International Peace Hospital, Hengshui, China
| | - Qian Liu
- Emergency Department, Harrison International Peace Hospital, Hengshui, China
| | - Yulan Yu
- Emergency Department, Harrison International Peace Hospital, Hengshui, China
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Metagenomic analysis of microbial community structure and function in a improved biofilter with odorous gases. Sci Rep 2022; 12:1731. [PMID: 35110663 PMCID: PMC8810771 DOI: 10.1038/s41598-022-05858-9] [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: 10/26/2021] [Accepted: 01/19/2022] [Indexed: 11/09/2022] Open
Abstract
Biofilters have been broadly applied to degrade the odorous gases from industrial emissions. A industrial scale biofilter was set up to treat the odorous gases. To explore biofilter potentials, the microbial community structure and function must be well defined. Using of improved biofilter, the differences in microbial community structures and functions in biofilters before and after treatment were investigated by metagenomic analysis. Odorous gases have the potential to alter the microbial community structure in the sludge of biofilter. A total of 90,016 genes assigned into various functional metabolic pathways were identified. In the improved biofilter, the dominant phyla were Proteobacteria, Planctomycetes, and Chloroflexi, and the dominant genera were Thioalkalivibrio, Thauera, and Pseudomonas. Several xenobiotic biodegradation-related pathways showed significant changes during the treatment process. Compared with the original biofilter, Thermotogae and Crenarchaeota phyla were significantly enriched in the improved biofilter, suggesting their important role in nitrogen-fixing. Furthermore, several nitrogen metabolic pathway-related genes, such as nirA and nifA, and sulfur metabolic pathway-related genes, such as fccB and phsA, were considered to be efficient genes that were involved in removing odorous gases. Our findings can be used for improving the efficiency of biofilter and helping the industrial enterprises to reduce the emission of waste gases.
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