keyword
MENU ▼
Read by QxMD icon Read
search

Ammonia oxidizing bacteria

keyword
https://www.readbyqxmd.com/read/27920767/ecophysiology-and-comparative-genomics-of-nitrosomonas-mobilis-ms1-isolated-from-autotrophic-nitrifying-granules-of-wastewater-treatment-bioreactor
#1
Soe Myat Thandar, Norisuke Ushiki, Hirotsugu Fujitani, Yuji Sekiguchi, Satoshi Tsuneda
Ammonia-oxidizing bacteria (AOB), which oxidize ammonia to nitrite in the first step of nitrification, play an important role in biological wastewater treatment systems. Nitrosomonas mobilis is an important and dominant AOB in various wastewater treatment systems. However, the detailed physiological and genomic properties of N. mobilis have not been thoroughly investigated because of limited success isolating pure cultures. This study investigated the key physiological characteristics of N. mobilis Ms1, which was previously isolated into pure culture from the nitrifying granules of wastewater treatment bioreactor...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27913871/n2o-emission-characteristics-and-its-affecting-factors-in-rain-fed-potato-fields-in-wuchuan-county-china
#2
Liwei Wang, Cheng Wang, Zhihua Pan, Hui Xu, Lin Gao, Peiyi Zhao, Zhiqiang Dong, Jingting Zhang, Guohui Cui, Sen Wang, Guolin Han, Hui Zhao
Representing an important greenhouse gas, nitrous oxide (N2O) emission from cultivated land is a hot topic in current climate change research. This study examined the influences of nitrogen fertilisation, temperature and soil moisture on the ammonia monooxygenase subunit A (amoA) gene copy numbers and N2O emission characteristics. The experimental observation of N2O fluxes was based on the static chamber-gas chromatographic method. The ammonia-oxidising bacteria (AOB) and ammonia-oxidising archaea (AOA) gene copy numbers in different periods were measured by real-time polymerase chain reaction (PCR)...
December 3, 2016: International Journal of Biometeorology
https://www.readbyqxmd.com/read/27909430/bacterial-active-community-cycling-in-response-to-solar-radiation-and-their-influence-on-nutrient-changes-in-a-high-altitude-wetland
#3
Verónica Molina, Klaudia Hernández, Cristina Dorador, Yoanna Eissler, Martha Hengst, Vilma Pérez, Chris Harrod
Microbial communities inhabiting high-altitude spring ecosystems are subjected to extreme changes in solar irradiance and temperature throughout the diel cycle. Here, using 16S rRNA gene tag pyrosequencing (cDNA) we determined the composition of actively transcribing bacteria from spring waters experimentally exposed through the day (morning, noon, and afternoon) to variable levels of solar radiation and light quality, and evaluated their influence on nutrient recycling. Solar irradiance, temperature, and changes in nutrient dynamics were associated with changes in the active bacterial community structure, predominantly by Cyanobacteria, Verrucomicrobia, Proteobacteria, and 35 other Phyla, including the recently described Candidate Phyla Radiation (e...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27900438/start-up-and-bacterial-community-compositions-of-partial-nitrification-in-moving-bed-biofilm-reactor
#4
Tao Liu, Yan-Jun Mao, Yan-Ping Shi, Xie Quan
Partial nitrification (PN) has been considered as one of the promising processes for pretreatment of ammonium-rich wastewater. In this study, a kind of novel carriers with enhanced hydrophilicity and electrophilicity was implemented in a moving bed biofilm reactor (MBBR) to start up PN process. Results indicated that biofilm formation rate was higher on modified carriers. In comparison with the reactor filled with traditional carriers (start-up period of 21 days), it took only 14 days to start up PN successfully with ammonia removal efficiency and nitrite accumulation rate of 90 and 91%, respectively, in the reactor filled with modified carriers...
November 30, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27898334/relative-contribution-of-ammonia-oxidizing-bacteria-and-other-members-of-nitrifying-activated-sludge-communities-to-micropollutant-biotransformation
#5
Yujie Men, Stefan Achermann, Damian E Helbling, David R Johnson, Kathrin Fenner
Improved micropollutant (MP) biotransformation during biological wastewater treatment has been associated with high ammonia oxidation activities, suggesting co-metabolic biotransformation by ammonia oxidizing bacteria as an underlying mechanism. The goal of this study was to clarify the contribution of ammonia oxidizing bacteria to increased MP degradation in nitrifying activated sludge (NAS) communities using a series of inhibition experiments. To this end, we treated a NAS community with two different ammonia oxidation inhibitors, namely octyne (OCT), a mechanistic inhibitor that covalently binds to ammonia monooxygenases, and allylthiourea (ATU), a copper chelator that depletes copper ions from the active center of ammonia monooxygenases...
November 22, 2016: Water Research
https://www.readbyqxmd.com/read/27881860/in-situ-restoration-of-one-stage-partial-nitritation-anammox-process-deteriorated-by-nitrate-build-up-via-elevated-substrate-levels
#6
Xiaolong Wang, Dawen Gao
The one-stage partial nitritation and anammox process (PN/A) has been a promising microbial process to remove ammonia from wastewater especially with low carbon/nitrogen ratio. The main breakdown was the deterioration caused by overgrowth of nitrite oxidizing bacteria (NOB) resulting effluent nitrate build-up in the PN/A process. This study presented an in-situ restoring strategy for suppressing NOB activity in a one-stage granular PN/A system deteriorated over 2 months, using elevated concentrations of substrates (ammonia and nitrite) under limited dissolved oxygen level...
November 24, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27871745/the-effect-of-dissolved-oxygen-concentration-do-on-oxygen-diffusion-and-bacterial-community-structure-in-moving-bed-sequencing-batch-reactor-mbsbr
#7
Yongfeng Cao, Chaosheng Zhang, Hongwei Rong, Guilin Zheng, Limin Zhao
The effect of dissolved oxygen concentration (DO) on simultaneous nitrification and denitrification was studied in a moving bed sequencing batch reactor (MBSBR) by microelectrode measurements and by real-time PCR. In this system, the biofilm grew on polyurethane foam carriers used to treat municipal sewage at five DO concentrations (1.5, 2.5, 3.5, 4.5 and 5.5 mg/L). The results indicated that the MBSBR exhibited good removal of chemical oxygen demand (92.43%) and nitrogen (83.73%) when DO concentration was 2...
January 1, 2017: Water Research
https://www.readbyqxmd.com/read/27863060/community-structure-of-partial-nitritation-anammox-biofilms-at-decreasing-substrate-concentrations-and-low-temperature
#8
Frank Persson, Carolina Suarez, Malte Hermansson, Elzbieta Plaza, Razia Sultana, Britt-Marie Wilén
Partial nitritation-anammox (PNA) permits energy effective nitrogen removal. Today PNA is used for treatment of concentrated and warm side streams at wastewater treatment plants, but not the more diluted and colder main stream. To implement PNA in the main stream, better knowledge about microbial communities at the typical environmental conditions is necessary. In order to investigate the response of PNA microbial communities to decreasing substrate availability, we have operated a moving bed biofilm reactor (MBBR) at decreasing reactor concentrations (311-27 mg-N l(-1) of ammonium) and low temperature (13°C) for 302 days and investigated the biofilm community using high throughput amplicon sequencing; quantitative PCR; and fluorescence in situ hybridization...
November 14, 2016: Microbial Biotechnology
https://www.readbyqxmd.com/read/27856762/nitrosomonas-europaea-cytochrome-p460-is-a-direct-link-between-nitrification-and-nitrous-oxide-emission
#9
Jonathan D Caranto, Avery C Vilbert, Kyle M Lancaster
Ammonia oxidizing bacteria (AOB) are major contributors to the emission of nitrous oxide (N2O). It has been proposed that N2O is produced by reduction of NO. Here, we report that the enzyme cytochrome (cyt) P460 from the AOB Nitrosomonas europaea converts hydroxylamine (NH2OH) quantitatively to N2O under anaerobic conditions. Previous literature reported that this enzyme oxidizes NH2OH to nitrite ([Formula: see text]) under aerobic conditions. Although we observe [Formula: see text] formation under aerobic conditions, its concentration is not stoichiometric with the NH2OH concentration...
November 16, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27845498/spatial-homogeneity-of-bacterial-and-archaeal-communities-in-the-deep-eastern-mediterranean-sea-surface-sediments
#10
Sabine Keuter, Baruch Rinkevich
The diversity of microorganisms inhabiting the deep sea surface sediments was investigated in 9 stations (700-1900 m depth) in the Levantine basin by 454 massive tag sequencing of the 16S rDNA V4 region using universal primers. In total, 108,811 reads (an average of 10,088 per sample) were assigned to 5014 bacterial and 966 archaeal operational taxonomic units (OTUs; at 97% cut off). The 55% of the reads were of archaea, indicating dominance of archaea over bacteria at eight of the stations. The diversity and estimated richness values were high (e...
June 2016: International Microbiology: the Official Journal of the Spanish Society for Microbiology
https://www.readbyqxmd.com/read/27842968/effects-of-earthworms-on-nitrification-and-ammonia-oxidizers-in-vermicomposting-systems-for-recycling-of-fruit-and-vegetable-wastes
#11
Kui Huang, Hui Xia, Guangyu Cui, Fusheng Li
Although it is known that earthworms enrich the nitrate content in their final products, the detailed mechanisms behind this are not well understood, and this is important for determining the agricultural value of vermicomposting. Hence, this study aimed to investigate the effects of earthworms on ammonia oxidization and to clarify the functions of ammonia-oxidizing bacteria and archaea (AOB and AOA) during vermicomposting of fruit and vegetable wastes (FVWs). For this, two dry systems using dry FVWs and a fresh system using fresh FVWs were adopted and compared during 60days of vermicomposting...
November 11, 2016: Science of the Total Environment
https://www.readbyqxmd.com/read/27837317/free-nitrous-acid-and-ph-determine-the-predominant-ammonia-oxidizing-bacteria-and-amount-of-n2o-in-a-partial-nitrifying-reactor
#12
Co Thi Kinh, Johwan Ahn, Toshikazu Suenaga, Nakanya Sittivorakulpong, Pongsak Noophan, Tomoyuki Hori, Shohei Riya, Masaaki Hosomi, Akihiko Terada
We investigated the effects of free ammonia (FA) and free nitrous acid (FNA) concentrations on the predominant ammonia-oxidizing bacteria (AOB) and the emission of nitrous oxide (N2O) in a lab-scale sequencing batch reactor for partial nitrification. The reactor was operated with stepwise increases in the NH4(+) loading rate, which resulted in a maximum FA concentration of 29.3 mg-N/L at pH 8.3. Afterwards, FNA was increased by a gradual decrease of pH, reaching its maximum concentration of 4.1 mg-N/L at pH 6...
November 11, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27836171/a-rapid-collection-of-yet-unknown-ammonia-oxidizers-in-pure-culture-from-activated-sludge
#13
Takuma Abe, Norisuke Ushiki, Hirotsugu Fujitani, Satoshi Tsuneda
Nitrification is an important reaction in the biological nitrogen removal process in wastewater treatment plants (WWTPs). As ammonia-oxidizing microbes are slow-growing and sensitive to environmental factors such as free ammonia, pure strains are hard to obtain, preventing our understanding of their physiological characteristics. To conquer this hurdle, we report a high-throughput isolation technique based on scattering signatures, which exploits the tendency of many ammonia-oxidizing bacteria (AOB) to form microcolonies in activated sludge...
January 1, 2017: Water Research
https://www.readbyqxmd.com/read/27822555/novel-syntrophic-populations-dominate-an-ammonia-tolerant-methanogenic-microbiome
#14
J A Frank, M Ø Arntzen, L Sun, L H Hagen, A C McHardy, S J Horn, V G H Eijsink, A Schnürer, P B Pope
Biogas reactors operating with protein-rich substrates have high methane potential and industrial value; however, they are highly susceptible to process failure because of the accumulation of ammonia. High ammonia levels cause a decline in acetate-utilizing methanogens and instead promote the conversion of acetate via a two-step mechanism involving syntrophic acetate oxidation (SAO) to H2 and CO2, followed by hydrogenotrophic methanogenesis. Despite the key role of syntrophic acetate-oxidizing bacteria (SAOB), only a few culturable representatives have been characterized...
September 2016: MSystems
https://www.readbyqxmd.com/read/27817146/the-response-of-ammonia-oxidizing-microorganisms-to-trace-metals-and-urine-in-two-grassland-soils-in-new-zealand
#15
Pengcheng Wang, Hong J Di, Keith C Cameron, Qiling Tan, Andriy Podolyan, Xiaohu Zhao, Ron G McLaren, Chengxiao Hu
An incubation experiment was conducted to investigate the response of ammonia-oxidizing bacteria (AOB), ammonia-oxidizing archaea (AOA), and the nitrification rate to the contamination of Cu, Zn, and Cd in two New Zealand grassland soils. The soils spiked with different concentrations of Cu (20 and 50 mg kg(-1)), Zn (20 and 50 mg kg(-1)), and Cd (2 and 10 mg kg(-1)) were incubated for 14 days and then treated with 500 mg kg(-1) urine-N before continuing incubation for a total of 115 days. Soils were sampled at intervals throughout the incubation...
November 6, 2016: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/27815274/quantitative-metaproteomics-highlight-the-metabolic-contributions-of-uncultured-phylotypes-in-a-thermophilic-anaerobic-digester
#16
Live H Hagen, Jeremy A Frank, Mirzaman Zamanzadeh, Vincent G H Eijsink, Phillip B Pope, Svein J Horn, Magnus Ø Arntzen
: In this study, we used multiple meta-omic approaches to characterize the microbial community and the active metabolic pathways of a stable industrial biogas reactor with food waste as the dominant feedstock, operating at thermophilic temperatures (60°C) and elevated levels of free ammonia (367 mg NH3-N/L). The microbial community was strongly dominated (76% of all 16S rRNA amplicon reads) by populations affiliated to the proteolytic bacterium, Coprothermobacter proteolyticus. Multiple Coprothermobacter-affiliated strains were detected, introducing an additional level of complexity seldom explored in biogas studies...
November 4, 2016: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/27812154/fabrication-of-bacteria-environment-cubes-with-dry-lift-off-fabrication-process-for-enhanced-nitrification
#17
S A P L Samarasinghe, Yiru Shao, Po-Jung Huang, Michael Pishko, Kung-Hui Chu, Jun Kameoka
We have developed a 3D dry lift-off process to localize multiple types of nitrifying bacteria in polyethylene glycol diacrylate (PEGDA) cubes for enhanced nitrification, a two-step biological process that converts ammonium to nitrite and then to nitrate. Ammonia-oxidizing bacteria (AOB) is responsible for converting ammonia into nitrite, and nitrite-oxidizing bacteria (NOB) is responsible for converting nitrite to nitrate. Successful nitrification is often challenging to accomplish, in part because AOB and NOB are slow growers and highly susceptible to many organic and inorganic chemicals in wastewater...
2016: PloS One
https://www.readbyqxmd.com/read/27807431/community-composition-and-abundance-of-bacterial-archaeal-and-nitrifying-populations-in-savanna-soils-on-contrasting-bedrock-material-in-kruger-national-park-south-africa
#18
Saskia Rughöft, Martina Herrmann, Cassandre S Lazar, Simone Cesarz, Shaun R Levick, Susan E Trumbore, Kirsten Küsel
Savannas cover at least 13% of the global terrestrial surface and are often nutrient limited, especially by nitrogen. To gain a better understanding of their microbial diversity and the microbial nitrogen cycling in savanna soils, soil samples were collected along a granitic and a basaltic catena in Kruger National Park (South Africa) to characterize their bacterial and archaeal composition and the genetic potential for nitrification. Although the basaltic soils were on average 5 times more nutrient rich than the granitic soils, all investigated savanna soil samples showed typically low nutrient availabilities, i...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27795404/quorum-quenching-of-nitrobacter-winogradskyi-suggests-that-quorum-sensing-regulates-fluxes-of-nitrogen-oxide-s-during-nitrification
#19
Brett L Mellbye, Andrew T Giguere, Peter J Bottomley, Luis A Sayavedra-Soto
: Quorum sensing (QS) is a widespread process in bacteria used to coordinate gene expression with cell density, diffusion dynamics, and spatial distribution through the production of diffusible chemical signals. To date, most studies on QS have focused on model bacteria that are amenable to genetic manipulation and capable of high growth rates, but many environmentally important bacteria have been overlooked. For example, representatives of proteobacteria that participate in nitrification, the aerobic oxidation of ammonia to nitrate via nitrite, produce QS signals called acyl-homoserine lactones (AHLs)...
October 25, 2016: MBio
https://www.readbyqxmd.com/read/27770728/effects-of-the-residual-ammonium-concentration-on-nob-repression-during-partial-nitritation-with-granular-sludge
#20
Vincent Poot, Maaike Hoekstra, Mitchell A A Geleijnse, Mark C M van Loosdrecht, Julio Pérez
Partial nitritation was stably achieved in a bench-scale airlift reactor (1.5L) containing granular sludge. Continuous operation at 20 °C treating low-strength synthetic wastewater (50 mg N-NH4(+)/L and no COD) achieved nitrogen loading rates of 0.8 g N-NH4(+)/(L·d) during partial nitritation. The switch between nitrite-oxidizing bacteria (NOB) repression and NOB proliferation was observed when ammonium concentrations in the reactor were below 2-5 mg N-NH4(+)/L for DO concentrations lower than 4 mg O2/L at 20 °C...
October 11, 2016: Water Research
keyword
keyword
112184
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"