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Denitrifying bacteria

Theoni Maria Massara, Simos Malamis, Albert Guisasola, Juan Antonio Baeza, Constantinos Noutsopoulos, Evina Katsou
Nitrous oxide (N2O) is an important pollutant which is emitted during the biological nutrient removal (BNR) processes of wastewater treatment. Since it has a greenhouse effect which is 265 times higher than carbon dioxide, even relatively small amounts can result in a significant carbon footprint. Biological nitrogen (N) removal conventionally occurs with nitrification/denitrification, yet also through advanced processes such as nitritation/denitritation and completely autotrophic N-removal. The microbial pathways leading to the N2O emission include hydroxylamine oxidation and nitrifier denitrification, both activated by ammonia oxidizing bacteria, and heterotrophic denitrification...
April 17, 2017: Science of the Total Environment
Zhi-Feng Zhou, Yan-Hong Yao, Ming-Xia Wang, Xiao-Hu Zuo
It has previously been confirmed that polycyclic aromatic hydrocarbons (PAHs) could be degraded by soil microbes coupling with denitrification, but the relationships among soil denitrifiers, PAHs, and nitrate under obligate anaerobic condition are still unclear. Here, co-effects of pyrene and nitrate on the activity and abundance of soil denitrifiers were investigated through a 45-day incubation experiment. Two groups of soil treatments with (N30) and without (N0) nitrate (30 mg kg(-1) dry soil) amendment were conducted, and each group contained three treatments with different pyrene concentrations (0, 30, and 60 mg kg(-1) dry soil denoted as P0, P30, and P60, respectively)...
April 18, 2017: Archives of Microbiology
Fenge Li, Mingcong Li, Wenchong Shi, Han Li, Zhongtao Sun, Zheng Gao
Denitrification was considered to be the critical process removing reactive nitrogen in estuarine ecosystem. In the present study, the abundance, diversity and community structure of nirK- and nirS-type denitrifiers were compared in sediments from the Yellow River estuary. Quantitative PCR (qPCR) showed that the abundance of the two types denitrifiers performed different distribution patterns among the samples, indicating their distinct habitat preference. Phylogenetic analysis revealed that the most sequences from cluster Ⅰ, Ⅲ, Ⅳ, Ⅴ for nirK-type denitrifiers were dominant distributed at the lower dissolved oxygen (DO) sites and sequences in other clusters were dominant at higher DO area...
April 17, 2017: Canadian Journal of Microbiology
Zhaoming Zheng, Yun Li, Jun Li, Yanzhuo Zhang, Wei Bian, Jia Wei, Baihang Zhao, Jingyue Yang
The aim of the present work was to evaluate the effects of carbon sources and chemical oxygen demand (COD)/NO2(-)-N ratios on the anammox-denitrification coupling process of the simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm. Also, the anammox activities of the SNAD biofilm were investigated under different temperature. Kaldnes rings taken from the SNAD biofilm reactor were operated in batch tests to determine the nitrogen removal rates. As a result, with the carbon source of sodium acetate, the appropriate COD/NO2(-)-N ratios for the anammox-denitrification coupling process were 1 and 2...
April 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Lihui Liu, Xiurong Xu, Yangchun Cao, Chuanjiang Cai, Hongxiao Cui, Junhu Yao
Studies proved that addition of nitrate in rumen could lead to reduction of methane emission. The mechanism of this function was involved in the competition effect of nitrate on hydrogen consumption and the inhibitory effect of generated nitrite on methanogen proliferation. The present study investigated an alternative mechanism that denitrifying anaerobic methane oxidizing (DAMO) bacteria, DAMO archaea and anammox bacteria may co-exist in rumen, therefore, more methane can be oxidized when addition of nitrate...
December 2017: AMB Express
Shuqing Li, Lina Song, Xiang Gao, Yaguo Jin, Shuwei Liu, Qirong Shen, Jianwen Zou
Manure composting is a significant source of atmospheric methane (CH4) and nitrous oxide (N2O) that are two potent greenhouse gases. The CH4 and N2O fluxes are mediated by methanogens and methanotrophs, nitrifying and denitrifying bacteria in composting manure, respectively, while these specific bacterial functional groups may interplay in CH4 and N2O emissions during manure composting. To test the hypothesis that bacterial functional gene abundances regulate greenhouse gas fluxes in windrow composting systems, CH4 and N2O fluxes were simultaneously measured using the chamber method, and molecular techniques were used to quantify the abundances of CH4-related functional genes (mcrA and pmoA genes) and N2O-related functional genes (amoA, narG, nirK, nirS, norB, and nosZ genes)...
2017: Frontiers in Microbiology
Zhiwei Li, Qingbo Chang, Shanshan Li, Mengchun Gao, Zonglian She, Liang Guo, Yangguo Zhao, Chunji Jin, Dong Zheng, Qiaoyan Xu
The impact of sulfadiazine on the performance, microbial activity and microbial community of a sequencing batch biofilm reactor (SBBR) were evaluated in treating mariculture wastewater due to the application of sulfadiazine as an antibiotic in mariculture. The COD and nitrogen removals kept stable at 0-6mg/L sulfadiazine and were inhibited at 10-35mg/L sulfadiazine. The microbial activities related to organic matter and nitrogen removals reduced with an increase in sulfadiazine concentration. The presence of sulfadiazine could affect the production and chemical composition of loosely bound extracellular polymeric substances (LB-EPS) and tightly bound EPS (TB-EPS) in the biofilm...
March 22, 2017: Bioresource Technology
Muhammad Ahmad, Sitong Liu, Nasir Mahmood, Asif Mahmood, Muhammad Ali, Maosheng Zheng, Jinren Ni
In this study, effects of porous carrier's size (polyurethane-based) on microbial characteristics were systematically investigated in addition to nitrogen removal performance in six microaerobic bioreactors. Among different sized carriers (50, 30, 20, 15,10, 5mm), 15mm carrier showed highest nitrogen removal (98%) due to optimal micro-environments created for aerobic nitrifiers in outer layer (0-7mm), nitrifiers and denitrifiers in middle layer (7-10mm) and anaerobic denitrifiers in inner layer (10-15mm). Candidatus brocadia, a dominant anammox bacteria, was solely concentrated close to centroid (0-70μm) and strongly co-aggregated with other bacterial communities in the middle layer of the carrier...
March 15, 2017: Bioresource Technology
Cui-Jing Zhang, Ju-Pei Shen, Yi-Fei Sun, Jun-Tao Wang, Li-Mei Zhang, Zhong-Ling Yang, Hong-Yan Han, Shi-Qiang Wan, Ji-Zheng He
Global climate change could have profound effects on belowground microbial communities and subsequently affect soil biogeochemical processes. The interactive effects of multiple co-occurring climate change factors on microbially mediated processes are not well understood. A four-factorial field experiment with elevated CO2, watering, nitrogen (N) addition and night warming was conducted in a temperate steppe of northern China. Real-time polymerase chain reaction and terminal-restriction fragment length polymorphism, combined with clone library techniques, were applied to examine the effects of those climate change factors on N-related microbial abundance and community composition...
April 1, 2017: FEMS Microbiology Ecology
Syed Afrin Azmi, Soumendranath Chatterjee
In this present study the population dynamics of the soil bacteria of some coastal villages, namely Padima, Jatimati, Chanpabani, Palsandapur, Bhagibaharampur, Duttapur, Gangadharpur, Gobindabasan, Somaibasan of Digha, West Bengal, India, was determined. In these villages the aerobic heterotrophic, Gram-negative, spore-forming, starch-hydrolyzing, Pseudomonas, nitrate-reducing, denitrifying, asymbiotic N2 fixing, nitrifying, phosphate-solubilizing bacterial populations ranged from 1.22 to 2.67 × 10(6), 0...
June 2016: 3 Biotech
Carol Barford, Joseph Montoya, Mark Altabet, Ralph Mitchell
Knowledge of isotopic discrimination, or fractionation, by denitrifying bacteria can benefit agricultural fertilizer management, wastewater treatment, and other applications. However, the complexity of N transformation pathways in the environment and the sensitivity of denitrification to environmental conditions warrant better isotopic distinction between denitrification and other processes, especially for oxygen isotopes. Here, we present a dataset of δ(18)O measurements in continuous culture of Paracoccus denitrificans...
March 21, 2017: Microbial Ecology
Xiaoya Xu, Xiaorui Liu, Yong Li, Yu Ran, Yapeng Liu, Qichun Zhang, Zheng Li, Yan He, Jianming Xu, Hongjie Di
Although the effect of simulated climate change on nitrous oxide (N2O) emissions and on associated microbial communities has been reported, it is not well understood if these effects are short-lived or long-lasting. Here, we conducted a field study to determine the interactive effects of simulated warmer and drier conditions on nitrifier and denitrifier communities and N2O emissions in an acidic soil and the longevity of the effects. A warmer (+2.3 °C) and drier climate (-7.4% soil moisture content) was created with greenhouses...
March 21, 2017: Environmental Science and Pollution Research International
Marcelle J van der Waals, Siavash Atashgahi, Ulisses Nunes da Rocha, Bas M van der Zaan, Hauke Smidt, Jan Gerritse
Benzene is an aromatic compound and harmful for the environment. Biodegradation of benzene can reduce the toxicological risk after accidental or controlled release of this chemical in the environment. In this study, we further characterized an anaerobic continuous biofilm culture grown for more than 14 years on benzene with nitrate as electron acceptor. We determined steady state degradation rates, microbial community composition dynamics in the biofilm, and the initial anaerobic benzene degradation reactions...
March 20, 2017: Applied Microbiology and Biotechnology
Cong Du, Chong-Wei Cui, Shan Qiu, Sheng-Nan Shi, Ang Li, Fang Ma
An aerobic denitrification system, initially bioaugmented with Pseudomonas strain T13, was established to treat coal-based ethylene glycol industry wastewater, which contained 3219 ± 86 mg/L total nitrogen (TN) and 1978 ± 14 mg/L NO3(-)-N. In the current study, a stable denitrification efficiency of 53.7 ± 4.7% and nitrite removal efficiency of 40.1 ± 2.7% were achieved at different diluted influent concentrations. Toxicity evaluation showed that a lower toxicity of effluent was achieved when industry wastewater was treated by stuffing biofilm communities compared to suspended communities...
March 18, 2017: Environmental Science and Pollution Research International
Ana M S Paulo, Rozelin Aydin, Mauricio R Dimitrov, Harm Vreeling, Ana J Cavaleiro, Pedro A García-Encina, Alfons J M Stams, Caroline M Plugge
The surfactant sodium lauryl ether sulfate (SLES) is widely used in the composition of detergents and frequently ends up in wastewater treatment plants (WWTPs). While aerobic SLES degradation is well studied, little is known about the fate of this compound in anoxic environments, such as denitrification tanks of WWTPs, nor about the bacteria involved in the anoxic biodegradation. Here, we used SLES as sole carbon and energy source, at concentrations ranging from 50 to 1000 mg L(-1), to enrich and isolate nitrate-reducing bacteria from activated sludge of a WWTP with the anaerobic-anoxic-oxic (A(2)/O) concept...
March 15, 2017: Applied Microbiology and Biotechnology
Shelesh Agrawal, Søren M Karst, Eva M Gilbert, Harald Horn, Per H Nielsen, Susanne Lackner
Implementation of partial nitritation anammox (PNA) in the mainstream (municipal wastewater treatment) is still under investigation. Microbial community structure and reactor type can influence the performance of PNA reactor; yet, little is known about the role of the community composition of the inoculum and the reactor configuration under mainstream conditions. Therefore, this study investigated the community structure of inocula of different origin and their consecutive community dynamics in four different lab-scale PNA reactors with 16S rRNA gene amplicon sequencing...
March 10, 2017: MicrobiologyOpen
Haitao Wang, Christopher W Marshall, Minying Cheng, Huijuan Xu, Hu Li, Xiaoru Yang, Tianling Zheng
Transition of populations from rural to urban living causes landscape changes and alters the functionality of soil ecosystems. It is unclear how this urbanization disturbs the microbial ecology of soils and how the disruption influences nitrogen cycling. In this study, microbial communities in turfgrass-grown soils from urban and suburban areas around Xiamen City were compared to microbial communities in the soils from rural farmlands. The potential N2O emissions, potential denitrification activity, and abundances of denitrifiers were higher in the rural farmland soils compared with the turfgrass soils...
March 10, 2017: Scientific Reports
Hengyuan Liu, Nan Chen, Chuanping Feng, Shuang Tong, Rui Li
This study aimed to investigate the effect of electro-stimulation on denitrifying bacterial growth in a bio-electrochemical reactor, and the growth were modeled using modified Gompertz model under different current densities at three C/Ns. It was found that the similar optimum current density of 250mA/m(2) was obtained at C/N=0.75, 1.00 and 1.25, correspondingly the maximum nitrate removal efficiencies were 98.0%, 99.2% and 99.9%. Moreover, ATP content and cell membrane permeability of denitrifying bacteria were significantly increased at optimum current density...
February 20, 2017: Bioresource Technology
Chuan Chen, Ruo-Chen Zhang, Xi-Jun Xu, Ning Fang, Ai-Jie Wang, Nan-Qi Ren, Duu-Jong Lee
The success of denitrifying sulfide removal (DSR) processes, which simultaneously degrade sulfide, nitrate and organic carbon in the same reactor, counts on synergetic growths of autotrophic and heterotrophic denitrifiers. Feeding wastewaters at high C/N ratio would stimulate overgrowth of heterotrophic bacteria in the DSR reactor so deteriorating the growth of autotrophic denitrifiers. The DSR tests at C/N=1.26:1, 2:1 or 3:1 and S/N =5:6 or 5:8 under anaerobic (control) or micro-aerobic conditions were conducted...
February 11, 2017: Bioresource Technology
Liang Fu, Jing Ding, Yong-Ze Lu, Zhao-Wei Ding, Ya-Nan Bai, Raymond J Zeng
Denitrifying anaerobic methane oxidation (DAMO) and Anammox co-culture system was investigated in hollow fiber membrane bioreactor (HfMBR) for the change of microbial community morphology and proportion. NO3(-)-N and NH4(+)-N removal rates reached 85.33 and 37.95mg/L/d on 193d. The inoculum microorganisms were flocs and the proportion of DAMO archaea, DAMO bacteria and Anammox bacteria was 11.0, 24.2 and 0.4%, respectively, but it changed to 74.3, 11.8, 5.6% in HfMBR, respectively. Interestingly, microorganisms formed biofilms on fibers surface and the biofilms included two layers: inner layer was thin and dominated by DAMO bacteria and Anammox bacteria; while the outer layer was thick made up of granules with 100-200μm diameter and dominated by DAMO archaea...
February 14, 2017: Bioresource Technology
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