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Denitrifying bacteria

Wei Zeng, Limin Zhang, Pengchao Fan, Jingjing Guo, Yongzhen Peng
Candidatus Accumulibacter has been identified as dominant polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus (P) removal (EBPR) from wastewater. This study revealed the relevance of community structure, abundance and seasonal population dynamics of Candidatus Accumulibacter to process operation of wastewater treatment plants (WWTPs) in China using ppk1 gene as phylogenetic marker. All sludge samples had properties of denitrifying P removal using nitrate as an electron acceptor. Accumulibacter abundance in the anaerobic-anoxic-oxic (A2 O) process was the highest (26% of total bacteria), and higher in winter than in summer with a better EBPR performance...
May 2018: Journal of Environmental Sciences (China)
Oliver Tiedt, Jonathan Fuchs, Wolfgang Eisenreich, Matthias Boll
Class I benzoyl-coenzyme A (BzCoA) reductases (BCRs) are key enzymes in the anaerobic degradation of aromatic compounds. They catalyze the ATP-dependent reduction of the central BzCoA intermediate and analogues of it to conjugated cyclic 1,5-dienoyl-CoAs probably by a radical-based, Birch-like reduction mechanism. Discovered in 1995, the enzyme from the denitrifying bacterium Thauera aromatica (BCRTar ) has so far remained the only isolated and biochemically accessible BCR, mainly because BCRs are extremely labile and their heterologous production has largely failed, so far...
May 16, 2018: Journal of Biological Chemistry
Gang Guo, Di Wu, George A Ekama, Tianwei Hao, Hamish Robert Mackey, Guanghao Chen
The recently developed Denitrifying Sulfur conversion-associated Enhanced Biological Phosphorus Removal (DS-EBPR) process has demonstrated simultaneous removal of organics, nitrogen and phosphorus with minimal sludge production in the treatment of saline/brackish wastewater. Its performance, however, is sensitive to operating and environmental conditions. In this study, the effects of temperature (20, 25, 30 and 35 °C) and the ratio of influent acetate to propionate (100-0, 75-25, 50-50, 25-75 and 0-100%) on anaerobic metabolism were investigated, and their optimal values/controls for performance optimization were identified...
April 16, 2018: Water Research
Lea Wittorf, Christopher M Jones, Germán Bonilla-Rosso, Sara Hallin
Reduction of nitrite to nitric oxide in denitrification is catalysed by two different nitrite reductases, encoded by nirS or nirK. Long considered mutually exclusive and functionally redundant in denitrifying bacteria, we show expression of both genes co-occurring in Pseudomonas stutzeri. The differential expression patterns between strain AN10 and JM300 in relation to oxygen and nitrate and their different denitrification phenotypes, with AN10 reducing nitrate more rapidly and accumulating nitrite, suggest that nirS and nirK can have different roles...
May 9, 2018: Research in Microbiology
Haitao Wang, Jack A Gilbert, Yongguan Zhu, Xiaoru Yang
Coastal ecosystems are hotspots for nitrogen cycling, and specifically for nitrogen removal from water and sediment through the coupled nitrification-denitrification process. Salinity is globally important in structuring bacterial and archaeal communities, but the association between salinity and microbially-mediated nitrification and denitrification remains unclear. The denitrification activity and composition and structure of microbial nitrifiers and denitrifiers were characterized across a gradient of manipulated salinity (0, 10, 20 and 30ppt) in a mangrove sediment...
August 1, 2018: Science of the Total Environment
Qi Yuan Sun, Jia Bing Li, Yue Ting Lai, Dang Yu Zhang, Wen Kang Qiu, Chun Shan Wu
Two estuary wetlands in Minjiang River, Shanyutan and Daoqingzhou, were selected as the research objects. Wetland sediments were collected to examine the effects of different salinity levels on nitrification processes in the wetland with a culture experiment. The results showed that the nitrification rate of sediment in Minjiang River estuary wetland was generally low. The highest nitrification rate of sediment in the Shanyutan wetland was 0.193 mg·kg-1 ·d-1 , while that in the Daoqingzhou wetland did not exceed 0...
April 2018: Ying Yong Sheng Tai Xue Bao, the Journal of Applied Ecology
Cameron M Callbeck, Gaute Lavik, Timothy G Ferdelman, Bernhard Fuchs, Harald R Gruber-Vodicka, Philipp F Hach, Sten Littmann, Niels J Schoffelen, Tim Kalvelage, Sören Thomsen, Harald Schunck, Carolin R Löscher, Ruth A Schmitz, Marcel M M Kuypers
Members of the gammaproteobacterial clade SUP05 couple water column sulfide oxidation to nitrate reduction in sulfidic oxygen minimum zones (OMZs). Their abundance in offshore OMZ waters devoid of detectable sulfide has led to the suggestion that local sulfate reduction fuels SUP05-mediated sulfide oxidation in a so-called "cryptic sulfur cycle". We examined the distribution and metabolic capacity of SUP05 in Peru Upwelling waters, using a combination of oceanographic, molecular, biogeochemical and single-cell techniques...
April 30, 2018: Nature Communications
Mui-Choo Jong, Jian-Qiang Su, Joshua T Bunce, Colin R Harwood, Jason R Snape, Yong-Guan Zhu, David W Graham
Inadequate sanitation can lead to the spread of infectious diseases and antimicrobial resistance (AMR) via contaminated water. Unfortunately, wastewater treatment is not universal in many developing and emerging countries, especially in rural and peri-urban locations that are remote from central sewers. As such, small-scale, more sustainable treatment options are needed, such as aerobic-Denitrifying Downflow Hanging Sponge (DDHS) bioreactors. In this study, DDHS reactors were assessed for such applications, and achieved over 79% and 84% removal of Chemical Oxygen Demand and Ammonium, respectively, and up to 71% removal of Total Nitrogen (TN) from domestic wastes...
April 13, 2018: Science of the Total Environment
Shilong He, Wan Yang, Meng Qin, Zhen Mao, Qigui Niu, Ming Han
Because ammonium (NH4 + -N) coexists with organic matter in some wastewaters, the possible adverse influences of organic matter become a major concern in the applications of anaerobic ammonium oxidation (anammox). In this study, the effects of acetate, as a representative of micro-molecule organic matter, on anammox were investigated. Efficient nitrogen removal was realized because denitrifying bacteria and anammox bacteria (AnAOB) had a better synergistic effect under the condition of chemical oxygen demand (COD) concentrations lower than 251 ± 7 mg L-1 ...
April 23, 2018: Chemosphere
Valérie Geoffroy, Geneviève Payette, Florian Mauffrey, Livie Lestin, Philippe Constant, Richard Villemur
Background: The biofilm of a methanol-fed, fluidized denitrification system treating a marine effluent is composed of multi-species microorganisms, among which Hyphomicrobium nitrativorans NL23 and Methylophaga nitratireducenticrescens JAM1 are the principal bacteria involved in the denitrifying activities. Strain NL23 can carry complete nitrate (NO[Formula: see text]) reduction to N2 , whereas strain JAM1 can perform 3 out of the 4 reduction steps. A small proportion of other denitrifiers exists in the biofilm, suggesting the potential plasticity of the biofilm in adapting to environmental changes...
2018: PeerJ
Xingang Zhou, Zhilin Wang, Huiting Jia, Li Li, Fengzhi Wu
Soil microbial communities have profound effects on the growth, nutrition and health of plants in agroecosystems. Understanding soil microbial dynamics in cropping systems can assist in determining how agricultural practices influence soil processes mediated by microorganisms. In this study, soil bacterial communities were monitored in a continuously monocropped Jerusalem artichoke (JA) system, in which JA was successively monocropped for 3 years in a wheat field. Soil bacterial community compositions were estimated by amplicon sequencing of the 16S rRNA gene...
2018: Frontiers in Microbiology
Késia S Lourenço, Noriko A Cassman, Agata S Pijl, Johannes A van Veen, Heitor Cantarella, Eiko E Kuramae
Organic vinasse, a residue produced during bioethanol production, increases nitrous oxide (N2 O) emissions when applied with inorganic nitrogen (N) fertilizer in soil. The present study investigated the role of the ammonia-oxidizing bacteria (AOB) community on the N2 O emissions in soils amended with organic vinasse (CV: concentrated and V: non-concentrated) plus inorganic N fertilizer. Soil samples and N2 O emissions were evaluated at 11, 19, and 45 days after fertilizer application, and the bacterial and archaea gene ( amo A) encoding the ammonia monooxygenase enzyme, bacterial denitrifier ( nir K, nir S, and nos Z) genes and total bacteria were quantified by real time PCR...
2018: Frontiers in Microbiology
Hui Qing, Oscar Omondi Donde, Cuicui Tian, Chunbo Wang, Xingqiang Wu, Shanshan Feng, Yao Liu, Bangding Xiao
AD-1, an aerobic denitrifier, was isolated from activated sludge and identified as Pseudomonas stutzeri. AD-1 completely removed NO3 - or NO2 - and removed 99.5% of NH4 + during individual culturing in a broth medium with an initial nitrogen concentration of approximately 50 mg L-1 . Results showed that larger amounts of nitrogen were removed through assimilation by the bacteria. And when NH4 + was used as the sole nitrogen source in the culture medium, neither NO2 - nor NO3 - was detected, thus indicating that AD-1 may not be a heterotrophic nitrifier...
April 18, 2018: Journal of Bioscience and Bioengineering
R G Sawers
Phthalic acid esters (phthalates) are anthropogenic compounds that are used as plasticizers. Unfortunately, because phthalates are non-covalently intercalated into plastic polymers they leach into the environment, accumulating in anoxic sediments. This has negative consequences for animal and human health. Denitrifying Betaproteobacteria, such as Aromatoleum aromaticum, can use ortho-phthalate, derived by ester hydrolysis, as a carbon and energy source. Mergelsberg et al. (in press) deconstruct the pathway whereby ortho-phthalic acid is converted, via the highly unstable phthaloyl-CoA, to the central intermediate of anaerobic aromatic degradation, benzoyl-CoA...
April 21, 2018: Molecular Microbiology
Rathnayake M L D Rathnayake, Mamoru Oshiki, Satoshi Ishii, Takahiro Segawa, Hisashi Satoh, Satoshi Okabe
Although nitric oxide (NO) emissions from anaerobic ammonium oxidation (anammox)-based processes were reported previously, the NO production pathways are poorly understood. Here, we investigated the NO production pathways in anammox granules in detail by combining 15 N-stable isotope tracer experiments with various inhibitors, microsensor measurements, and transcriptome analysis for key genes of NO2 - reduction. NO was emitted from the anammox granules, which account for 0.07% of the N2 emission. 15 N-stable isotope-tracer experiments indicated that most of the N2 was produced by anammox bacteria, whereas NO was produced from NO2 - reduction by anammox and denitrifying bacteria...
April 20, 2018: Environmental Science & Technology
M Azari, A V Le, M Lübken, M Denecke
A mathematical model for a granular biofilm reactor for leachate treatment was validated by long-term measured data to investigate the mechanisms and drivers influencing biological nitrogen removal and microbial consortia dynamics. The proposed model, based on Activated Sludge Model (ASM1), included anaerobic ammonium oxidation (anammox), nitrifying and heterotrophic denitrifying bacteria which can attach and grow on granular activated carbon (GAC) particles. Two kinetic descriptions for the model were proposed: with and without soluble microbial products (SMP) and extracellular polymeric substance (EPS)...
April 2018: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Qibin Wang, Renda Yao, Quan Yuan, Hui Gong, Heng Xu, Nasir Ali, Zhengyu Jin, Jiane Zuo, Kaijun Wang
Sequence batch reactors (SBR) with simultaneous feeding/draw mode and low-strength wastewater were used for the cultivation of aerobic granules, and analysis of bacterial community diversity were conducted. Results revealed that the ratio of chemical oxygen demand/total nitrogen removal amount for R1 with real wastewater and R2 with synthetic wastewater decreased from 9.9 to 8.7 and, 29.9 to 21.1, respectively, when volumetric exchange ratio (VER) decreased from 90% (stage I) to 50% (stage II), indicating that organic matter in real and low-strength wastewater was fully utilized with lower VER by denitrifying bacteria...
April 5, 2018: Bioresource Technology
Kati Blomberg, Pascal Kosse, Anna Mikola, Anna Kuokkanen, Tommi Fred, Mari Heinonen, Michela Mulas, Manfred Luebken, Marc Wichern, Riku Vahala
An Activated Sludge Model #3 (ASM3)-based, pseudo-mechanistic model describing nitrous oxide (N2O) production was created in this study to provide more insight into the dynamics of N2O production, consumption, and emissions at a full-scale wastewater treatment plant (WWTP). N2O emissions at the studied WWTP are monitored throughout the plant with an FT-IR analyzer, while the developed model encountered N2O production in the biological reactors via both ammonia oxidizing bacteria (AOB) nitrification and heterotrophic denitrifiers...
April 18, 2018: Environmental Science & Technology
Xiaolong Wang, Yuegen Yan, Dawen Gao
Low-strength ammonium is still a challenge for the mainstream deammonification because of nitrate over-accumulation. In this study, the threshold of influent ammonium concentration of one-stage deammonification system with granular sludge was investigated, by stepwise decreasing influent ammonium from high concentrations (280mg/L to 140mg/L) to the low concentration (70mg/L) in 108d at 32°C without aeration. Results showed that, under 70mg/L NH4 + -N, ΔNO3 - -N/ΔNH4 + -N ratio increased to 0.2, deviated from the theoretical value of 0...
April 10, 2018: Science of the Total Environment
Nuan Yang, Guoqiang Zhan, Tingting Wu, Yanyan Zhang, Qinrui Jiang, Daping Li, Yuanying Xiang
To investigate the effect of air-exposed biocathode (AEB) on the performance of single-chamber microbial fuel cell (SCMFC), wastewater quality, bioelectrochemical characteristics and the electrode biofilms were researched. It was demonstrated that exposing the biocathode to air was beneficial to nitrogen removal and current generation. In Test 1 of 95% AEB, removal rates of ammonia, total nitrogen (TN) and chemical oxygen demand (COD) reached 99.34%±0.11%, 99.34%±0.10% and 90.79%±0.12%, respectively. The nitrogen removal loading rates were 36...
April 2018: Journal of Environmental Sciences (China)
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