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Denitrifying bacteria

Hannah Gaimster, Lisa Chalklen, Mark Alston, John T Munnoch, David J Richardson, Andrew J Gates, Gary Rowley
Nitrous oxide (N2O) is a stable, ozone depleting greenhouse gas. Emissions of N2O into the atmosphere continue to rise, primarily due to the use of nitrogen-containing fertilizers by soil denitrifying microbes. It is clear more effective mitigation strategies are required to reduce emissions. One way to help develop future mitigation strategies is to address the currently poor understanding of transcriptional regulation of the enzymes used to produce and consume N2O. With this ultimate aim in mind we performed RNA-seq on a model soil denitrifier, Paracoccus denitrificans, cultured anaerobically under high N2O and low N2O emitting conditions, and aerobically under zero N2O emitting conditions to identify small RNAs (sRNAs) with potential regulatory functions transcribed under these conditions...
2016: Frontiers in Microbiology
Sophie-Marie Martirani-Von Abercron, Daniel Pacheco, Patricia Benito-Santano, Patricia Marín, Silvia Marqués
Although bacterial anaerobic degradation of mono-aromatic compounds has been characterized in depth, the degradation of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene has only started to be understood in sulfate reducing bacteria, and little is known about the anaerobic degradation of PAHs in nitrate reducing bacteria. Starting from a series of environments which had suffered different degrees of hydrocarbon pollution, we used most probable number (MPN) enumeration to detect and quantify the presence of bacterial communities able to degrade several PAHs using nitrate as electron acceptor...
2016: Frontiers in Microbiology
Xinghui Xia, Ting Liu, Zhifeng Yang, Greg Michalski, Shaoda Liu, Zhimei Jia, Sibo Zhang
Present-day estimations of global nitrogen loss (N-loss) are underestimated. Commonly, N-loss from rivers is thought to be caused by denitrification only in bed-sediments. However, coupled nitrification-denitrification occurring in overlying water with suspended sediments (SPS) where oxic and anoxic/low oxygen zones may coexist is ignored for N-loss in rivers. Here the Yellow and Yangtze Rivers were taken as examples to investigate the effect of SPS, which exists in many rivers of the world, on N loss through coupled nitrification-denitrification with nitrogen stable ((15)N) isotopic tracer simulation experiments and in-situ investigation...
November 17, 2016: Science of the Total Environment
Xin Li, Yali Liu, Mingxing Chu, Aimin Liu
A novel process, inclined-plates hydrolytic tank (IHT) and membrane bioreactor (MBR), was used to treat domestic sewage continuously. In this study, the effects of carriers' addition on operational performances of IHT-MBR were studied at the hydraulic retention time of 5.4 h and the recycling rate of 200%. Experimental results indicated the removal efficiencies of chemical oxygen demand, total nitrogen and total phosphorus reached 86.8%, 82.9% and 89.6%, respectively, corresponding trans-membrane pressure decreased to 1...
November 2016: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Mengyao Gui, Qian Chen, Tao Ma, Maosheng Zheng, Jinren Ni
Effects of heavy metals on aerobic denitrification have been poorly understood compared with their impacts on anaerobic denitrification. This paper presented effects of four heavy metals (Cd(II), Cu(II), Ni(II), and Zn(II)) on aerobic denitrification by a novel aerobic denitrifying strain Pseudomonas stutzeri PCN-1. Results indicated that aerobic denitrifying activity decreased with increasing heavy metal concentrations due to their corresponding inhibition on the denitrifying gene expression characterized by a time lapse between the expression of the nosZ gene and that of the cnorB gene by PCN-1, which led to lower nitrate removal rate (1...
November 16, 2016: Applied Microbiology and Biotechnology
Xiaomei Zhang, Xiufu Hua, Xiuping Yue
For quinoline-denitrifying degradation, very few researches focused on shortcut denitrification process and its bacterial community characteristics. In this study, complete and shortcut denitrification systems were constructed simultaneously for quinoline degradation. By calculation, specific quinoline removal rates were 0.905 and 1.123 g/(gVSS d), respectively, in the complete and shortcut systems, and the latter was 1.24 times of the former. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), high-throughput sequencing, and quantitative PCR (qPCR) techniques based on 16S rRNA were jointly applied to compare microbial community structures of two systems...
November 16, 2016: Applied Microbiology and Biotechnology
Hao Song, Jiahui Xu, Michel Lavoie, Xiaoji Fan, Guangfu Liu, Liwei Sun, Zhengwei Fu, Haifeng Qian
Physico-chemical parameters, hydrological conditions, and microbial interactions can affect the growth and persistence of cyanobacteria, but the interacting effects among these bloom-forming factors are still poorly known. This hampers our capacity to predict the occurrence of cyanobacterial bloom accurately. Here, we studied the relationship between temperature, N and P cycles, and the microbial community abundance and diversity at 0.5 m under the surface of West Lake (China) from January 21 to November 20, 2015, in order to better understand the key factors regulating temporal changes in the cyanobacterial community...
November 15, 2016: Applied Microbiology and Biotechnology
Lijuan Feng, Kun Chen, Doudou Han, Jing Zhao, Yi Lu, Guangfeng Yang, Jun Mu, Xiangjiong Zhao
This study explored the water purification performances of solid-phase denitrification systems filled with either untreated, acid and alkali pretreated corncob, rice straw and rice hulls. Nitrate reduction improved via pretreatments was found in ascending order from corncob, rice straw and rice hulls systems due to their various chemical compositions, while the pretreated rice hull systems still had the lowest nitrate reduction efficiencies (<90%). Besides, nitrite accumulation only frequently detected (<0...
November 4, 2016: Bioresource Technology
Shiva Ladan, Pierre-André Jacinthe
Nitrous oxide (N2O) is an atmospheric constituent implicated in climate warming and stratospheric ozone depletion. Both bacteria and fungi participate in N2O production, but information is lacking with regard to the relative contribution of bacterial and fungal denitrifiers to the denitrification process in agricultural soils. The selective inhibition (SI) technique is widely used to assess the contribution of different groups of microbes to soil processes, but success of the technique depends on the effectiveness of the inhibitors...
November 8, 2016: Environmental Science. Processes & Impacts
Yvonne A Lipsewers, Ellen C Hopmans, Filip J R Meysman, Jaap S Sinninghe Damsté, Laura Villanueva
Denitrifying and anammox bacteria are involved in the nitrogen cycling in marine sediments but the environmental factors that regulate the relative importance of these processes are not well constrained. Here, we evaluated the abundance, diversity, and potential activity of denitrifying, anammox, and sulfide-dependent denitrifying bacteria in the sediments of the seasonally hypoxic saline Lake Grevelingen, known to harbor an active microbial community involved in sulfur oxidation pathways. Depth distributions of 16S rRNA gene, nirS gene of denitrifying and anammox bacteria, aprA gene of sulfur-oxidizing and sulfate-reducing bacteria, and ladderane lipids of anammox bacteria were studied in sediments impacted by seasonally hypoxic bottom waters...
2016: Frontiers in Microbiology
Hao Wang, Zhengkui Li, Huayang Han
Ecological remediation is one of the most practical methods for removing nutrients from river ecosystems. In this study, transformation and fate of nitrate and ammonium among four different ecological restoration treatments were investigated by stable (15)N isotope pairing technique combined with quantitative polymerase chain reaction and high-throughput sequencing technology. The results of (15)N mass-balance model showed that there were three ways to the fate of nitrogen: precipitated in the sediment, absorbed by Elodea nuttallii (E...
October 29, 2016: Environmental Science and Pollution Research International
Ruixia Hao, Chengcheng Meng, Jianbing Li
Two main operating parameters (influent C/N ratio and electric current intensity) were examined for their impacts on the denitrifying bacterial community structure in an integrated system of three-dimensional biofilm-electrode reactor and sulfur autotrophic denitrification (3DBER-SAD). It was found that genus β-proteobacteria played a leading role under different operating conditions. The influent C/N ratio illustrated a great impact on denitrifying bacteria diversity. When the C/N ratio decreased from 1.07 to 0...
October 28, 2016: Journal of Industrial Microbiology & Biotechnology
Yingxue Sun, Dandan Shen, Xiaoli Zhou, Na Shi, Yuan Tian
The treatment performance and spatial microbial community structure of three parallel denitrifying biological filters (DNBFs) operated with methanol, ethanol and acetate, respectively, were explored. The acetate-fed DNBF presented the highest denitrification rate and NOx-N (NO2-N and NO3-N) removal efficiency, while the methanol-fed DNBF showed the lowest carbon consumption and NOx-N removal efficiency. Distinct spatial distribution patterns of terminal restriction fragment length polymorphism fingerprints were observed among the DNBFs...
2016: SpringerPlus
Songhe Zhang, Si Pang, Peifang Wang, Chao Wang, Chuan Guo, Felix Gyawu Addo, Yi Li
Submerged macrophytes play important roles in constructed wetlands and natural water bodies, as these organisms remove nutrients and provide large surfaces for biofilms, which are beneficial for nitrogen removal, particularly from submerged macrophyte-dominated water columns. However, information on the responses of biofilms to submerged macrophytes and nitrogen molecules is limited. In the present study, bacterial community structure and denitrifiers were investigated in biofilms on the leaves of four submerged macrophytes and artificial plants exposed to two nitrate concentrations...
October 26, 2016: Scientific Reports
Linlin Yao, Yanxin Wang, Lei Tong, Yamin Deng, Yonggang Li, Yiqun Gan, Wei Guo, Chuangju Dong, Yanhua Duan, Ke Zhao
The occurrence of 14 antibiotics (fluoroquinolones, tetracyclines, macrolides and sulfonamides) in groundwater and surface water at Jianghan Plain was investigated during three seasons. The total concentrations of target compounds in the water samples were higher in spring than those in summer and winter. Erythromycin was the predominant antibiotic in surface water samples with an average value of 1.60μg/L, 0.772μg/L and 0.546μg/L respectively in spring, summer and winter. In groundwater samples, fluoroquinolones and tetracyclines accounted for the dominant proportion of total antibiotic residues...
October 13, 2016: Ecotoxicology and Environmental Safety
Upendra Kumar, J Berliner, Totan Adak, Prakash C Rath, Avro Dey, Somnath S Pokhare, Nitiprasad N Jambhulkar, P Panneerselvam, Anjani Kumar, Shyamranjan D Mohapatra
Application of pesticide in agricultural fields is "unnecessary evil" for non-target microflora and fauna. Hence, to identify the safer pesticide molecules against non-target microbes, a long-term pesticide experiment was initiated at National Rice Research Institute, Cuttack, India. In the present study, the effect of continuous application of chlorpyrifos (0.5kgha(-1)) in rice fields on non-target groups of soil microbes and nematodes was studied for seven seasons (four wet and three dry seasons) during 2009-2013...
October 13, 2016: Ecotoxicology and Environmental Safety
Yun-Feng Duan, Xian-Wang Kong, Andreas Schramm, Rodrigo Labouriau, Jørgen Eriksen, Søren O Petersen
: Grassland cultivation can mobilize large pools of N in the soil, with a potential for N leaching and N2O emissions. Spraying with the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) before cultivation was simulated with soil columns where residue distribution corresponded to ploughing or rotovation, to study effects of soil-residue contact on N transformations. DMPP was sprayed on above-ground parts of ryegrass and white clover before incorporation. During a 42-day incubation, soil mineral N dynamics, potential ammonia oxidation (PAO) and denitrifying enzyme activity (DEA), nitrifier and denitrifier populations, and N2O emissions were investigated...
October 14, 2016: Applied and Environmental Microbiology
Zhao-Wei Ding, Yong-Ze Lu, Liang Fu, Jing Ding, Raymond J Zeng
In this study, the coculture system of denitrifying anaerobic methane oxidation (DAMO) microbes and anaerobic ammonium oxidation (anammox) bacteria was successfully enriched in a hollow-fiber membrane biofilm reactor (HfMBR) using freshwater sediment as the inoculum. The maximal removal rates of nitrate and ammonium were 78 mg N/L/day (131 mg N/m(2)/day) and 26 mg N/L/day (43 mg N/m(2)/day), respectively. Due to the high rate of methane mass transfer in HfMBR, the activity of DAMO archaea continued to increase during the enrichment period, indicating that HfMBR could be a powerful tool to enrich DAMO microorganisms...
October 12, 2016: Applied Microbiology and Biotechnology
Yue Yuan, Jinjin Liu, Bin Ma, Ye Liu, Bo Wang, Yongzhen Peng
This study presents a novel strategy to improve the removal efficiency of nitrogen and phosphorus from municipal wastewater by feeding sequencing batch reactor (SBR) with sludge alkaline fermentation products as carbon sources. The performances of two SBRs treating municipal wastewater (one was fed with sludge fermentation products; F-SBR, and the other without sludge fermentation products; B-SBR) were compared. The removal efficiencies of total nitrogen (TN) and phosphorus (PO4(3-)-P) were found to be 82.9% and 96...
October 8, 2016: Bioresource Technology
Wei Li, Xiao-Yu Lin, Jun-Jie Chen, Chao-Yang Cai, Ghulam Abbas, Zhi-Qiang Hu, He-Ping Zhao, Ping Zheng
Denitratation (nitrite produced from nitrate), has the potential applications in wastewater treatment by combining with ANAMMOX process. The occurrence of denitratation has been shown to be effected qualitatively by various parameters in the environment. A more quantitative understanding can be obtained using enrichment cultures in lab-scale experiments, yet information on the enrichment of functional microorganisms responsible for denitratation is lacking. In this study, a stable denitratation-dominated culture was obtained from methylotrophic denitrifying culture...
October 6, 2016: Applied Microbiology and Biotechnology
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