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Ammonia oxidizing bacteria

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https://www.readbyqxmd.com/read/28549327/achievement-performance-and-characteristics-of-microbial-products-in-a-partial-nitrification-sequencing-batch-reactor-as-a-pretreatment-for-anaerobic-ammonium-oxidation
#1
Heng Dong, Keyi Zhang, Xiao Han, Bin Du, Qin Wei, Dong Wei
This study was carried out to evaluate achievement, performance and characteristics of microbial products in a partial nitrification sequencing batch reactor as a pretreatment for anaerobic ammonium oxidation (anammox). After 100 days long-term operation, the effluent NO2(-)-N/NH4(+)N ratio of the reactor was average at 1.3 and NO3(-)-N concentration was low by controlling low dissolved oxygen (DO) concentration, which was considered as the ideal influent for anammox. Specific oxygen uptake rate (SOUR) implied that (SOUR)NH4 and (SOUR)NO2 of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) in sludge changed from 21...
May 20, 2017: Chemosphere
https://www.readbyqxmd.com/read/28544522/metagenomic-potential-for-and-diversity-of-n-cycle-driving-microorganisms-in-the-bothnian-sea-sediment
#2
Olivia Rasigraf, Julia Schmitt, Mike S M Jetten, Claudia Lüke
The biological nitrogen cycle is driven by a plethora of reactions transforming nitrogen compounds between various redox states. Here, we investigated the metagenomic potential for nitrogen cycle of the in situ microbial community in an oligotrophic, brackish environment of the Bothnian Sea sediment. Total DNA from three sediment depths was isolated and sequenced. The characterization of the total community was performed based on 16S rRNA gene inventory using SILVA database as reference. The diversity of diagnostic functional genes coding for nitrate reductases (napA;narG), nitrite:nitrate oxidoreductase (nxrA), nitrite reductases (nirK;nirS;nrfA), nitric oxide reductase (nor), nitrous oxide reductase (nosZ), hydrazine synthase (hzsA), ammonia monooxygenase (amoA), hydroxylamine oxidoreductase (hao), and nitrogenase (nifH) was analyzed by blastx against curated reference databases...
May 23, 2017: MicrobiologyOpen
https://www.readbyqxmd.com/read/28543691/emergent-macrophytes-modify-the-abundance-and-community-composition-of-ammonia-oxidizers-in-their-rhizosphere-sediments
#3
Dayong Zhao, Xiaowei He, Rui Huang, Wenming Yan, Zhongbo Yu
Ammonia oxidation is a crucial process in global nitrogen cycling, which is catalyzed by the ammonia oxidizers. Emergent plants play important roles in the freshwater ecosystem. Therefore, it is meaningful to investigate the effects of emergent macrophytes on the abundance and community composition of ammonia oxidizers. In the present study, two commonly found emergent macrophytes (Zizania caduciflora and Phragmitas communis) were obtained from freshwater lakes and the abundance and community composition of the ammonia-oxidizing prokaryotes in the rhizosphere sediments of these emergent macrophytes were investigated...
May 22, 2017: Journal of Basic Microbiology
https://www.readbyqxmd.com/read/28540424/screening-and-optimizing-of-inhibitors-for-ammonia-oxidizing-bacteria-in-sediments-of-malodorous-river
#4
Jianhua Wang, Yan He, Jin Zhu, Huimin Guan, Minsheng Huang
The proper use of selective ammonia-oxidizing archaea (AOA) and/or ammonia-oxidizing bacteria (AOB) inhibitors is critical to distinguish AOA and AOB contribution. In this research, three inhibitors including ampicillin, dicyandiamide (DCD), and allylthiourea (ATU) were examined mainly focusing on inhibiting dosage, adaptability, and effects. The results showed that the optimized inhibitory dosage of ampicillin, DCD, and ATU was separately 1.5 g L(-1), 1 mM, and 25 μM. Among the three inhibitors, ATU exhibited the strongest and persistent inhibition effects and resulted in up to 90% inhibition in the AOB-enriched culture...
May 24, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28526785/effects-of-arginine-on-growth-virulence-gene-expression-and-stress-tolerance-by-streptococcus-mutans
#5
Brinta Chakraborty, Robert A Burne
Streptococcus mutans is a common constituent of oral biofilms and a primary etiologic agent of human dental caries. The bacteria associated with dental caries have a potent ability to produce organic acids from dietary carbohydrates and to grow and metabolize in acidic conditions. In contrast, many commensal bacteria produce ammonia through the arginine deiminase system (ADS), which moderates the pH of oral biofilms. Arginine metabolism by the ADS is a significant deterrent to the initiation and progression of dental caries...
May 19, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28523826/occurrence-and-abundance-of-ammonia-oxidizing-archaea-and-bacteria-from-the-surface-to-below-the-water-table-in-deep-soil-and-their-contributions-to-nitrification
#6
Lei Zheng, Xue Zhao, Guibing Zhu, Wei Yang, Chao Xia, Tao Xu
Using molecular biology methods (qualitative and quantitative PCR), we determined the occurrence and abundance of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) from a dry inland soil in Basel, Switzerland, and from the riparian zone of Baiyangdian Lake, China. We also determined the contributions of these microorganisms to ammonia oxidization at different depths based on the nitrification rate. The number of archaeal amoA genes (the key functional gene in AOA) was larger than the number of bacterial amoA genes in each sample, suggesting a dominant role for the AOA amoA gene in environments with a low ammonium concentration...
May 19, 2017: MicrobiologyOpen
https://www.readbyqxmd.com/read/28521169/heterotrophic-ammonia-and-nitrate-bio-removal-over-nitrite-hanbon-performance-and-microflora
#7
Wei Li, Zhao-Yang Cai, Zi-Jun Duo, Yao-Feng Lu, Ke-Xin Gao, Ghulam Abbas, Meng Zhang, Ping Zheng
A novel Heterotrophic Ammonia and Nitrate Bio-removal Over Nitrite (Hanbon) process, combining Short Nitrate Reduction (SNR) with Anaerobic Ammonia Oxidation (Anammox), was developed in a lab-scale continuous up-flow reactor. The substrate effects were investigated to characterize the performance of Hanbon process, and the corresponding microflora information was also revealed. Our results showed that the optimal substrate ratio of NH4(+)-N:NO3(-)-N:COD for the Hanbon process was 0.65:1:2.2. The volumetric nitrogen removal rate was up to 9...
May 13, 2017: Chemosphere
https://www.readbyqxmd.com/read/28509546/growth-of-nitrosococcus-related-ammonia-oxidizing-bacteria-coincides-with-extremely-low-ph-values-in-high-strength-nitrogen-wastewater
#8
Alexandra Fumasoli, Helmut Buergmann, David G Weissbrodt, George F Wells, Karin Beck, Joachim Mohn, Eberhard Morgenroth, Kai M Udert
Ammonia oxidation decreases the pH in wastewaters where the alkalinity is limited relative to the total ammonia. The activity of ammonia oxidizing bacteria (AOB), however, typically decreases with pH and often ceases completely in slightly acidic wastewaters. Nevertheless, low pH nitrification has been reported in reactors treating human urine, but it is not clear which organisms are involved. In this study, we followed the population dynamics of ammonia oxidizing organisms and reactor performance in synthetic, synthetic fully hydrolysed urine as the pH decreased over time in response to a decrease in the loading rate...
May 16, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28500038/enrichment-and-physiological-characterization-of-a-cold-adapted-nitrite-oxidizer-nitrotoga-sp-from-eelgrass-sediments
#9
Kento Ishii, Hirotsugu Fujitani, Kentaro Soh, Tatsunori Nakagawa, Reiji Takahashi, Satoshi Tsuneda
Nitrite-oxidizing bacteria (NOB) are responsible for the second step of nitrification in natural and engineered ecosystems. The recently discovered genus Nitrotoga belongs to the Betaproteobacteria and has potentially high environmental importance. Although environmental clones affiliated with Nitrotoga are widely distributed, the limited number of cultivated Nitrotoga results in poor understanding of their ecophysiological features. In this study, we successfully enriched the non-marine cold-adapted Nitrotoga sp...
May 12, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28499263/effect-of-fumigation-with-chloropicrin-on-soil-bacterial-communities-and-genes-encoding-key-enzymes-involved-in-nitrogen-cycling
#10
Jun Li, Bin Huang, Qiuxia Wang, Yuan Li, Wensheng Fang, Dongdong Yan, Meixia Guo, Aocheng Cao
Chloropicrin (CP) is a potential alternative for methyl bromide as a soil fumigant given that the use of methyl bromide has become limited. However, little is known about how fumigation with CP affects the condition of the soil microbial community. In this study, 16S rRNA amplicon sequencing and quantitative PCR were combined to investigate the effect of CP on soil bacterial community. In total, 938,922 effective reads were obtained from 18 samples and clustered into 58,662 operational taxonomic units at a similarity cut-off of 97%...
May 9, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28486170/weak-magnetic-field-a-powerful-strategy-to-enhance-partial-nitrification
#11
Zhibin Wang, Xiaolin Liu, Shou-Qing Ni, Jian Zhang, Xu Zhang, Hafiz Adeel Ahmad, Baoyu Gao
Partial nitrification (PN) combined with anaerobic ammonium oxidation process has been recognized as a promising technology for the removal of nitrogenous contaminants from wastewater. This research aimed to investigate the potential of external magnetic field for enhancing the PN process in short and long term laboratory-scale experiments. Different strength magnetic fields (0, 5, 10, 15, 20 and 25 mT) were evaluated in short-term batch tests and 5 mT magnetic field was found to have better ability to increase the activities of aerobic ammonium oxidizing bacteria (AOB) of PN consortium...
April 26, 2017: Water Research
https://www.readbyqxmd.com/read/28476240/effect-of-free-ammonium-and-free-nitrous-acid-on-the-activity-aggregate-morphology-and-eps-distribution-of-ammonium-oxidizing-bacteria-in-partial-nitrification
#12
Qian Yao, Dangcong Peng, Bo Wang, Yuanyuan Chen, Jiaqi Li, Qiaodi Zhao, Binbin Wang
Successful partial nitrification not only guarantees the inhibition of nitrite oxidation, but also does not excessively retard the ammonia oxidation rate. Therefore, the performance of ammonium oxidizing bacteria (AOB) during partial nitrification is fundamental to this process. In this study, two lab-scale partial nitrification bioreactors containing different inhibition conditions-one with free ammonium (FA) inhibition, the other with free nitrous acid (FNA) inhibition-were used to compare the differences between activity, quantity, aggregation morphology and extracellular polymeric substance (EPS) distribution of AOB...
May 2, 2017: Journal of Bioscience and Bioengineering
https://www.readbyqxmd.com/read/28475989/development-of-a-novel-proton-exchange-membrane-free-integrated-mfc-system-with-electric-membrane-bioreactor-and-air-contact-oxidation-bed-for-efficient-and-energy-saving-wastewater-treatment
#13
Changfei Gao, Lifen Liu, Fenglin Yang
A novel combined system integrating MFC and electric membrane bioreactor (EMBR) was developed, in which a quartz sand chamber (QSC) was used, replacing expensive proton exchange membrane (PEM). An air contact oxidation bed (ACOB) and embedded trickling filter (TF) with filled volcano rock, was designed to increase dissolved oxygen (DO) in cathodic EMBR to save aeration cost. Membrane fouling in EMBR was successful inhibited/reduced by the generated bioelectricity of the system. The combined system demonstrated superior effluent quality in removing chemical oxygen demand (>97%) and ammonia nitrogen (>93%) during the stable operation, and the phosphorus removal was about 50%...
April 25, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28470424/nitrogen-transformation-under-different-dissolved-oxygen-levels-by-the-anoxygenic-phototrophic-bacterium-marichromatium-gracile
#14
Xuan Hong, Zhongwei Chen, Chungui Zhao, Suping Yang
Marichromatium gracile: YL28 (M. gracile YL28) is an anoxygenic phototrophic bacterial strain that utilizes ammonia, nitrate, or nitrite as its sole nitrogen source during growth. In this study, we investigated the removal and transformation of ammonium, nitrate, and nitrite by M. gracile YL28 grown in a combinatorial culture system of sodium acetate-ammonium, sodium acetate-nitrate and sodium acetate-nitrite in response to different initial dissolved oxygen (DO) levels. In the sodium acetate-ammonium system under aerobic conditions (initial DO = 7...
June 2017: World Journal of Microbiology & Biotechnology
https://www.readbyqxmd.com/read/28465056/unraveling-microbial-structure-and-diversity-of-activated-sludge-in-a-full-scale-simultaneous-nitrogen-and-phosphorus-removal-plant-using-metagenomic-sequencing
#15
Jianhua Guo, Bing-Jie Ni, Xiaoyu Han, Xueming Chen, Philip Bond, Yongzhen Peng, Zhiguo Yuan
Activated sludge contains highly complex microbial communities, which play crucial roles in pollutant removal performance in wastewater treatment plants (WWTPs). Metagenomic sequencing was applied to characterize microbial community and functional profiles within activated sludge from a full-scale municipal WWTP carrying out simultaneous nitrogen and phosphorous removal (SNPR). We applied the assembled contigs (N90 of 591bp) and predicted genes to conduct taxonomic and function annotations, respectively. Results revealed the extraordinary microbial diversity of activated sludge, which included detection of minority populations that are difficult to be explored by traditional molecular methods...
July 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28460292/efficient-simultaneous-partial-nitrification-anammox-and-denitrification-snad-system-equipped-with-a-real-time-dissolved-oxygen-do-intelligent-control-system-and-microbial-community-shifts-of-different-substrate-concentrations
#16
Xin Wen, Benzhou Gong, Jian Zhou, Qiang He, Xiaoxia Qing
Simultaneous partial nitrification, anammox and denitrification (SNAD) process was studied in a sequencing batch biofilm reactor (SBBR) fed with synthetic wastewater in a range of 2200 mgN/L ∼ 50 mgN/L. Important was an external real-time precision dissolved oxygen (DO) intelligent control system that consisted of feed forward control system and feedback control system. This DO control system permitted close control of oxygen supply according to influent concentration, effluent quality and other environmental factors in the reactor...
April 21, 2017: Water Research
https://www.readbyqxmd.com/read/28448139/intermittent-aeration-suppresses-nitrite-oxidizing-bacteria-in-membrane-aerated-biofilms-a-model-based-explanation
#17
Yunjie Ma, Carlos Domingo-Félez, Benedek Gy Plósz, Barth F Smets
Autotrophic ammonium oxidation in membrane-aerated biofilm reactors (MABRs) can make treatment of ammonium-rich wastewaters more energy-efficient, especially within the context of short-cut ammonium removal. The challenge is to exclusively enrich ammonium-oxidizing bacteria (AOB). To achieve nitritation, strategies to suppress nitrite-oxidizing bacteria (NOB) are needed, which are ideally grounded on an understanding of underlying mechanisms. In this study, a nitrifying MABR was operated under intermittent aeration...
May 11, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28446904/dynamic-response-of-ammonia-oxidizers-to-four-fertilization-regimes-across-a-wheat-rice-rotation-system
#18
Jichen Wang, Lei Ni, Yang Song, Geoff Rhodes, Jing Li, Qiwei Huang, Qirong Shen
Ammonia oxidation by microorganisms is a rate-limiting step of the nitrification process and determines the efficiency of fertilizer utilized by crops. Little is known about the dynamic response of ammonia-oxidizers to different fertilization regimes in a wheat-rice rotation system. Here, we examined ammonia-oxidizing bacteria (AOB) and archaea (AOA) communities across eight representative stages of wheat and rice growth and under four fertilization regimes: no nitrogen fertilization (NNF), chemical fertilization (CF), organic-inorganic mixed fertilizer (OIMF) and organic fertilization (OF)...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28433911/enhanced-nitrogen-removal-by-membrane-aerated-nitritation-anammox-in-a-bioelectrochemical-system
#19
Yuli Yang, Xiaojin Li, Xiaoli Yang, Zhen He
A bioelectrochemical system (BES) containing membrane-aerated nitritation-anammox in its cathode has been developed for enhancing nitrogen removal. Long-term performance and microbial community structure were investigated. The BES using loop operation and external voltage achieved the highest total nitrogen removal efficiency of 94.8±7.7%, and COD removal of 98.2±3.3% at hydraulic retention time of 60h and the lumen pressure of 10psi. The energy consumption of the system was 0.90kWhkgN(-1) or 0.38kWhkg COD(-1)...
April 9, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28426987/a-review-on-nitrous-oxide-n2o-emissions-during-biological-nutrient-removal-from-municipal-wastewater-and-sludge-reject-water
#20
REVIEW
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
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