Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| effect of continuous cd feeding on the performance of a nitrification reactor. | the inhibitory effect of cd on nitrification was investigated in a continuous-flow system with enriched nitrifying bacteria. the maximum specific ammonium utilization rate and the half-saturation constant were found as 671 mg nh(4)-n/g vss day and 0.48 mg/l, respectively. in the case of continuous cd input at 1 and 2.5 mg/l, nitrification was inhibited by 30% and 47%, respectively. inhibition ranged from 20% to 40% and no further increase in inhibition was exhibited in new runs except at 10 mg/l ... | 2009 | 18677441 |
| use of quantitative real-time pcr to monitor population dynamics of ammonia-oxidizing bacteria in batch process. | a quantitative real-time pcr (qpcr) assay with the taqman system was used to quantify 16s rrna genes of beta-proteobacterial ammonia-oxidizing bacteria (aob) in a batch nitrification bioreactor. five different sets of primers, together with a taqman probe, were used to quantify the 16s rrna genes of beta-proteobacterial aob belonging to the nitrosomonas europaea, nitrosococcus mobilis, nitrosomonas nitrosa, and nitrosomonas cryotolerans clusters, and the genus nitrosospira. we also used pcr foll ... | 2008 | 18712556 |
| comparative analysis of ammonia monooxygenase (amoa) genes in the water column and sediment-water interface of two lakes and the baltic sea. | the functional gene amoa was used to compare the diversity of ammonia-oxidizing bacteria (aob) in the water column and sediment-water interface of the two freshwater lakes plusssee and schöhsee and the baltic sea. nested amplifications were used to increase the sensitivity of amoa detection, and to amplify a 789-bp fragment from which clone libraries were prepared. the larger part of the sequences was only distantly related to any of the cultured aob and is considered to represent new clusters o ... | 2008 | 18721144 |
| removal of ammonium via simultaneous nitrification-denitrification nitrite-shortcut in a single packed-bed batch reactor. | a polyurethane packed-bed-biofilm sequential batch reactor was fed with synthetic substrate simulating the composition of uasb reactor effluents. two distinct ammonia nitrogen concentrations (125 and 250 mg l(-1)) were supplied during two sequential long-term experiments of 160 days each (320 total). cycles of 24h under intermittent aeration for periods of 1h were applied, and ethanol was added as a carbon source at the beginning of each anoxic period. nitrite was the main oxidized nitrogen comp ... | 2009 | 18793833 |
| [regulation of soil nitrification with nitrification inhibitors and related mechanisms]. | to improve the use efficiency of fertilizer n while alleviate its pollution is one of the keys in ensuring the high yield and good quality of agricultural products and the sustainable development of agriculture and environment, for which, applying nitrification inhibitors to retard the course of soil nitrification is an efficient measure. in this review, the definition, screening criteria, major varieties being widely used, and action mechanisms of nitrification inhibitors were introduced, and t ... | 2008 | 18808037 |
| effect of metasystox-r on marine nitrosomonas sp. as a nitrification inhibitor. | metasystox-r is a systemic soluble liquid insecticide for the control of aphids on brassica vegetable crops, cotton and lupins and it is possible enter to the marine environment and may be have a hazard effects for the marine organisms and nitrification processes. effect of metasystox-r on ammonia oxidizing activity by marine nitrosomonas sp. was investigated by determining nitrification inhibitor assay in the cell suspension. results showed that 8 microg ml(-1) of metasystox-r with pi50 = 4.48 ... | 2008 | 18817147 |
| evaluation of performance and microbial ecology of sequencing batch reactor and membrane bioreactor treating thin-film transistor liquid crystal display wastewater. | in taiwan, a substantial amount of thin-film transistor liquid crystal display (tft-lcd) wastewater is produced daily due to an increasing production of the opto-electronic industry in recent years. the main components of tft-lcd wastewater include dimethyl sulphoxide (dmso), monoethanolamine (mea), and tetra-methyl ammonium hydroxide (tmah), which are recognized as non-or slow-biodegradable organic compounds and limited information is available regarding their biological treatablility. this stu ... | 2008 | 18824808 |
| structure, function and significance of rh proteins in red cells. | the present article reviews recent data concerning the structure and function of the rh-associated glycoprotein (rhag) and considers what can be inferred about the structure and functional significance of the d and ce polypeptides. | 2008 | 18832935 |
| [ammonia-oxidizing bacteria community composition at the root zones of aquatic plants after ecological restoration]. | to investigate the effects of aquatic plants on ammonia-oxidizing bacteria (aob) at their root zones, four species of aquatic plants were selected, phragmites communis, typha angustifolia l., potamogeton crispus l., and limnanthemun nymphoides, which were widely used in ecological restorations. aob in the samples were enumerated by most-probable-number (mpn) method. nested polymerase chain reaction-denaturing gradient gel electrophoresis (pcr-dgge) procedures were performed with ammonia oxidizer ... | 2008 | 18839565 |
| [variation of diversity and activity of ammonia-oxidizing bacteria community in the integrated vertical-flow constructed wetlands]. | the activity of ammonia-oxidizing bacteria (aob) in different layers of integrated vertical-flow constructed wetlands (ivcw) treating eutrophic scenic water was measured, and the diversity and spatial distribution of aob community structure in ivcw was investigated using pcr-dgge. the results indicated that because of the integrated influence of competition of plant rhizodeposition, heterotrophic bacteria, do and ammonia concentration, there were significant spatial differences in the activity a ... | 2008 | 18839566 |
| construction of a consortium comprising ammonia-oxidizing bacteria and denitrifying bacteria isolated from marine sediment. | a unique consortium of ammonia-oxidizing bacteria (aob) and denitrifying bacteria was obtained via a long-term, 3-step cultivation of isolates from organically-enriched marine sediment. we developed this microbial consortium for possible applications in the remediation of degraded habitats in closed aquaculture or other aquatic environments via microbial degradation. analysis of media components found definitive evidence of nitrogen removal via the coupling of ammonia-oxidation and denitrificati ... | 2008 | 18839627 |
| the effect of hydroxylamine on the activity and aggregate structure of autotrophic nitrifying bioreactor cultures. | addition of hydroxylamine (nh2oh) to autotrophic biomass in nitrifying bioreactors affected the activity, physical structure, and microbial ecology of nitrifying aggregates. when nh2oh is added to nitrifying cultures in 6-h batch experiments, the initial nh3-n uptake rates were physiologically accelerated by a factor of 1.4-13. nh2oh addition caused a 20-40% decrease in the median aggregate size, broadened the shape of the aggregate size distribution by up to 230%, and caused some of the microco ... | 2009 | 18846553 |
| the monovalent cation leak in overhydrated stomatocytic red blood cells results from amino acid substitutions in the rh-associated glycoprotein. | overhydrated hereditary stomatocytosis (ohst) is a rare dominantly inherited hemolytic anemia characterized by a profuse membrane leak to monovalent cations. here, we show that ohst red cell membranes contain slightly reduced amounts of rh-associated glycoprotein (rhag), a putative gas channel protein. dna analysis revealed that the ohst patients have 1 of 2 heterozygous mutations (t182g, t194c) in rhag that lead to substitutions of 2 highly conserved amino acids (ile61arg, phe65ser). unexpected ... | 2009 | 18931342 |
| modulation of the ligand-field anisotropy in a series of ferric low-spin cytochrome c mutants derived from pseudomonas aeruginosa cytochrome c-551 and nitrosomonas europaea cytochrome c-552: a nuclear magnetic resonance and electron paramagnetic resonance study. | cytochromes of the c type with histidine-methionine (his-met) heme axial ligation play important roles in electron-transfer reactions and in enzymes. in this work, two series of cytochrome c mutants derived from pseudomonas aeruginosa (pa c-551) and from the ammonia-oxidizing bacterium nitrosomonas europaea (ne c-552) were engineered and overexpressed. in these proteins, point mutations were induced in a key residue (asn64) near the met axial ligand; these mutations have a considerable impact bo ... | 2008 | 18947229 |
| expression of mera, amoa and hao in continuously cultured nitrosomonas europaea cells exposed to zinc chloride additions. | the effects of zncl2 additions on a mercuric reductase, mera, ammonia monooxygenase, amoa, and hydroxylamine (nh2oh) oxidoreductase, hao, gene expression were examined in continuously cultured nitrosomonas europaea cells. the reactor was operated for 85 days with a 6.9 d hydraulic retention time and with four successive additions of zncl2 achieving maximum concentrations from 3 to 90 microm zn2+. continuously cultured n. europaea cells were more resistant to zn2+ inhibition than previously exami ... | 2009 | 18949750 |
| [isolation, identification and characterization of nitroso-bacteria in one-step completely nitrogen removal process]. | to study the characteristics of the nitroso-bacteria in one-step completely autotrophic nitrogen removal process. | 2008 | 18956760 |
| relative abundance and diversity of ammonia-oxidizing archaea and bacteria in the san francisco bay estuary. | ammonia oxidation in marine and estuarine sediments plays a pivotal role in the cycling and removal of nitrogen. recent reports have shown that the newly discovered ammonia-oxidizing archaea can be both abundant and diverse in aquatic and terrestrial ecosystems. in this study, we examined the abundance and diversity of ammonia-oxidizing archaea (aoa) and betaproteobacteria (beta-aob) across physicochemical gradients in san francisco bay--the largest estuary on the west coast of the usa. in contr ... | 2008 | 18973621 |
| 17alpha-ethinylestradiol transformation via abiotic nitration in the presence of ammonia oxidizing bacteria. | impacts of trace concentrations of estrogens on aquatic ecosystems are a serious environmental concern, with their primary source being wastewater treatment facility effluents. increased removal of 17alpha-ethinylestradiol (ee2) has been reported for activated sludge treatment with long enough solids retention time for nitrification. previous work based on batch tests with nitrosomonas europaea and nitrifying activated sludge at high ee2 concentrations (>300 000 ng/l) and high nh4-n concentratio ... | 2008 | 18983084 |
| non-invasive self-referencing electrochemical sensors for quantifying real-time biofilm analyte flux. | current techniques for characterizing biofilm physiology lack the signal filtering capability required for quantifying signals associated with real time biologically active transport. though a great deal was learned from previous investigations, no results have been reported on the characterization of in vivo, real time biofilm flux using non-invasive (non-destructive) techniques. this article introduces the self-referencing technique for applications in biofilm physiology. self-referencing is a ... | 2009 | 18985610 |
| emerging models for nitrogen removal in treatment wetlands. | engineering textbooks tell a simple story about nitrification and denitrification. classic nitrification-denitrification theory begins with the bacterial genera nitrosomonas and nitrobacter performing ammonia and nitrite oxidation, respectively. then facultative or obligate anaerobic bacteria denitrify by oxidizing organic carbon with nitrate. recent advances in environmental microbiology have revealed previously unknown bacteria and pathways in the nitrogen cycle that tell a far more complex st ... | 2008 | 19004390 |
| structure and function of denitrifying and nitrifying bacterial communities in relation to the plant species in a constructed wetland. | the community structure and potential activities of nitrifying and denitrifying bacteria were studied in the rhizosphere of typha latifolia and phragmites australis present in a free water system constructed wetland (cw). potential nitrate reduction and nitrification activities were shown to be significantly higher in the rhizosphere when compared with the nonvegetated sediment. higher rates were generally obtained for p. australis. the community structure of denitrifying bacteria in the rhizosp ... | 2009 | 19049502 |
| characterization of the pyrophosphate-dependent 6-phosphofructokinase from methylococcus capsulatus bath. | an active pyrophosphate-dependent 6-phosphofructokinase (ppi-pfk) from the thermotolerant methanotroph methylococcus capsulatus bath, containing a six-residue polyhistidine tag, was characterized. the enzyme was homodimeric (2 x 45 kda), nonallosteric and most active at ph 7.0. ppi-pfk catalyzed reactions of ppi-dependent phosphorylation of fructose-6-phosphate (f-6-p) (k(m) 2.27 mm and v(max) 7.6 u mg(-1) of protein), sedoheptulose-7-phosphate (k(m) 0.027 mm and v(max) 31 u mg(-1)) and ribulose ... | 2008 | 19054082 |
| microbial characterization of nitrification in a shallow, nitrogen-contaminated aquifer, cape cod, massachusetts and detection of a novel cluster associated with nitrifying betaproteobacteria. | groundwater nitrification is a poorly characterized process affecting the speciation and transport of nitrogen. cores from two sites in a plume of contamination were examined using culture-based and molecular techniques targeting nitrification processes. the first site, located beneath a sewage effluent infiltration bed, received treated effluent containing o2 (>300 microm) and nh4+ (51-800 microm). the second site was 2.5 km down-gradient near the leading edge of the ammonium zone within the co ... | 2009 | 19059672 |
| whole-genome transcriptional and physiological responses of nitrosomonas europaea to cyanide: identification of cyanide stress response genes. | nitrosomonas europaea (atcc 19718) is one of several nitrifying species that participate in the biological removal of nitrogen from wastewater by oxidizing ammonia to nitrite, the first step in nitrification. because nitrification is quite sensitive to cyanide, a compound often encountered in wastewater treatment plants, we characterized the physiological and transcriptional responses of n. europaea cells to cyanide. the cells were extremely sensitive to low concentrations of cyanide, with no-(2 ... | 2009 | 19072843 |
| community composition of ammonia-oxidizing bacteria and archaea in rice field soil as affected by nitrogen fertilization. | little information is available on the ecology of ammonia-oxidizing bacteria (aob) and archaea (aoa) in flooded rice soils. consequently, a microcosm experiment was conducted to determine the effect of nitrogen fertilizer on the composition of aob and aoa communities in rice soil by using molecular analyses of ammonia monooxygenase gene (amoa) fragments. experimental treatments included three levels of n (urea) fertilizer, i.e. 50, 100 and 150 mgnkg(-1) soil. soil samples were operationally divi ... | 2009 | 19091507 |
| inactivation of nitrosomonas europaea and pathogenic escherichia coli by chlorine and monochloramine. | the purpose of this study was to measure the chlorine and monochloramine inactivation kinetics of nitrosomonas europaea at 21 degrees c in the presence and absence of particles. the inactivation kinetics rates were compared with those obtained with escherichia coli o157:h7. the results show that, in pure water, the use of free chlorine produced 4 log10 of n. europaea inactivation at a ct value of 0.8 mg.min l(-1), whereas monochloramine yielded 4 log10 of inactivation at ct values of approximate ... | 2008 | 19108551 |
| interaction of the mechanism-based inactivator acetylene with ammonia monooxygenase of nitrosomonas europaea. | the ammonia monooxygenase (amo) of nitrosomonas europaea is a metalloenzyme that catalyses the oxidation of ammonia to hydroxylamine. we have identified histidine 191 of amoa as the binding site for the oxidized mechanism-based inactivator acetylene. binding of acetylene changed the molecular mass of his-191 from 155.15 to 197.2 da (+42.05), providing evidence that acetylene was oxidized to ketene (ch2co; 42.04 da) which binds specifically to his-191. it must be assumed that his-191 is part of t ... | 2009 | 19118368 |
| removal of ammonia by immobilized nitrosomonas europaea in a biotrickling filter packed with polyurethane foam. | a biotrickling filter with nitrosomonas europaea immobilized on polyurethane foam is proposed for treating ammonia contaminated air. the effect of the surface velocity of the recirculation medium, nitrite concentration, ph, empty bed residence time (ebrt) and ammonia inlet load on the nh(3) removal process was investigated. the total amount of biomass immobilized on the carrier was 3.29+/-0.52 x 10(10) cells g(-1) dry carrier. the maximum elimination capacity of the biotrickling filter was 270 g ... | 2009 | 19118862 |
| [stability of short-cut nitrification using immobilized ammonia-oxidizing bacteria]. | the ammonia-oxidizing bacteria were immobilized by copolymer with cell proliferation technology. the effects of nh(4+) -n load, hrt, free ammonia (fa) and organic matter on short-cut nitrification process were studied. the results showed that when influent nh(4+) -n load were 100 mg/l, 150 mg/l and 200 mg/l respectively, effluent nh(4+) -n concentration was less than 10 mg/l. when the system run for 3 h, 6 h and 12 h, corresponding to influent nh(4+) -n concentration of 25.8 mg/l, 51.1 mg/l and ... | 2008 | 19143381 |
| [comparison of microbial community structure in mbrs treating different wastewater]. | in order to investigate the microbial community structures in different membrane bioreactors, total bacterial genomic dna was extracted from biomass in four mbrs treating different wastewater. the microbial community structures were studied by polymerase chain reaction-denaturing gradient gel electrophoresis (pcr-dgge) and cloning-sequencing. furthermore, and the sequences were used for homology analysis and then two phylogenetic trees were constructed. results indicate that each mbr owns its sp ... | 2008 | 19143399 |
| microbial ecology and performance of ammonia oxidizing bacteria (aob) in biological processes treating petrochemical wastewater with high strength of ammonia: effect of na(2)co(3) addition. | this study evaluated nitrification performance and microbial ecology of aob in a full-scale biological process, powder activated carbon treatment (pact), and a pilot-scale biological process, moving bed biofilm reactor (mbbr), treating wastewater collected from a petrochemical industry park. the petrochemical influent wastewater characteristics showed a relative low carbon to nitrogen ratio around 1 with average cod and ammonia concentrations of 310 mg/l and 325 mg-n/l, respectively. the average ... | 2009 | 19182331 |
| activity and composition of ammonia oxidizing bacterial communities and emission dynamics of nh3 and n2o in a compost reactor treating organic household waste. | to monitor emissions of nh(3) and n(2)o during composting and link these to ammonia oxidation rates and the community structure of ammonia oxidizing bacteria (aob). | 2009 | 19210570 |
| in situ characterization of nitrifying biofilm: minimizing biomass loss and preserving perspective. | methods for characterizing nitrifying bacteria within biofilms are of key importance to understand and optimize the nitrification kinetics of attached growth treatment facilities. in this work, we propose an analytical protocol based upon environmental scanning electron microscopy (esem) and confocal laser scanning microscopy (cslm) in combination with fluorescent in situ hybridization (fish) to characterize the structure of nitrifying biofilm as it remains attached to the original reactor subst ... | 2009 | 19217138 |
| crystal structure of a two-domain multicopper oxidase: implications for the evolution of multicopper blue proteins. | the two-domain multicopper oxidases are proposed to be key intermediates in the evolution of three-domain multicopper oxidases. a number of two-domain multicopper oxidases have been identified from genome sequences and are classified as type a, type b, or type c on the basis of the predicted location of the type 1 copper center. the crystal structure of blue copper oxidase, a type c two-domain multicopper oxidase from nitrosomonas europaea, has been determined to 1.9 a resolution. blue copper ox ... | 2009 | 19224923 |
| nitrifying community structures and nitrification performance of full-scale municipal and swine wastewater treatment plants. | this study evaluated nitrification performance and microbial ecology of nitrifying sludge in two full-scale wastewater treatment plants (wwtps) including a municipal wwtp treating 20mgnl(-1) of ammonium and a swine wwtp treating 220mgnl(-1) of ammonium. these two plants differed in both wastewater characteristics and operating parameters, such as influent cod, tkn, ammonium, hydraulic retention time, and solids retention time, even though both plants achieve >85% nitrification efficiency. by emp ... | 2009 | 19246073 |
| construction of recombinant nitrosomonas europaea expressing green fluorescent protein in response to co-oxidation of chloroform. | transcriptional fusions with gfp driven by the promoter region of mbla (ne2571) in ppro/mbla4 and clpb (ne2402) in ppro/clpb7 were used to transform the ammonia-oxidizing bacterium nitrosomonas europaea (atcc 19718). the two genes were chosen because their transcript levels were found at much higher levels in n. europaea in response to oxidation of chloroform and chloromethane. in n. europaea transformed with ppro/mbla4, green fluorescent protein (gfp)-dependent fluorescence increased from 3- to ... | 2009 | 19247648 |
| [effect of intermittent aeration on growth kinetics of nitrifiers and mechanism for no2- accumulation]. | in order to investigate shortcut nitrification, an intermittent-aeration sbr was employed to treat the domestic wastewater containing low concentration of nh4+ . the results shows that under the srts of 10, 5, 2.5 and 1.25 d, no2- produced in effluent were built up to 18, 19, 14 and 5 mg/l, respectively, with accumulation ratio of 73%, 85%, 91% and 78% respectively. as to the continuous-aeration sbr, however, the no2- accumulation ratios were only 14%, 21%, 31% and 34%. in addition, the correspo ... | 2009 | 19353862 |
| [mechanism of ammonium removal in the completely autotrophic nitrogen removal in one reactor process]. | different synthetic wastewaters were used in the batch tests to analyze the intermediate products and the nitrogen balance, and to study the mechanism of ammonium removal in the completely autotrophic nitrogen removal in one reactor process with the sludge cultured in the sbbr completely autotrophic nitrogen removal system. the results showed that 62% of ammonium was converted to such nitrogen compounds as no2-, no3-, nh2 oh, n2h4, no, no2, n2o and n2 without addition of organic carbon, and n2 t ... | 2009 | 19353865 |
| ammonia biofiltration and community analysis of ammonia-oxidizing bacteria in biofilters. | biological removal of ammonia was investigated using compost and sludge as packing materials in laboratory-scale biofilters. the aim of this study is to characterize the composition of ammonia-oxidizing bacteria (aob) in two biofilters designed to remove ammonia. experimental tests and measurements included analysis of removal efficiency and metabolic products. the inlet concentration of ammonia applied was 20-100 mg m(-3). removal efficiencies of bfc and bfs were in the range of 97-99% and 95-9 ... | 2009 | 19359165 |
| removal of hydrogen sulfide and ammonia from gas mixtures by co-immobilized cells using a new configuration of two biotrickling filters. | the simultaneous removal of h(2)s and nh(3) was investigated using two biotrickling filters packed with polyurethane foam cubes. one biotrickling filter was inoculated with thiobacillus thioparus atcc 23645 for the removal of h(2)s (btt) and the other filter with nitrosomonas europaea atcc 19718 for the removal of nh(3) (bne). three different configurations were studied by modification of the gas line and recirculation medium line. the best results were obtained with the bne biotrickling filter ... | 2009 | 19381001 |
| optimization of three fish procedures for in situ detection of anaerobic ammonium oxidizing bacteria in biological wastewater treatment. | fluorescence in situ hybridization (fish) using fluorochrome-labeled dna oligonucleotide probes has been successfully applied for in situ detection of anaerobic ammonium oxidizing (anammox) bacteria. however, application of the standard fish protocols to visualize anammox bacteria in biofilms from a laboratory-scale wastewater reactor produced only weak signals. increased signal intensity was achieved either by modifying the standard fish protocol, using peptide nucleic acid probes (pna fish), o ... | 2009 | 19389431 |
| greenhouse gas microbiology in wet and dry straw crust covering pig slurry. | liquid manure (slurry) storages are sources of gases such as ammonia (nh(3)) and methane (ch(4)). danish slurry storages are required to be covered to reduce nh(3) emissions and often a floating crust of straw is applied. this study investigated whether physical properties of the crust or crust microbiology had an effect on the emission of the potent greenhouse gases ch(4) and nitrous oxide (n(2)o) when crust moisture was manipulated ("dry", "moderate", and "wet"). the dry crust had the deepest ... | 2009 | 19398529 |
| the bacterial diversity in an anaerobic ammonium-oxidizing (anammox) reactor community. | an anaerobic ammonium-oxidation (anammox) reactor was operated for more than 500 days and the anammox activity of the biomass in the reactor reached 0.58 kg n(total)/kg vss d. the removal ratios of no2(-)-n to nh4(+)-n in both reactor and activity tests were nearly 1.1. the bacterial diversity in the reactor was investigated by analysis of 16s rrna gene clone libraries and quantitative real-time pcr (qpcr). the analysis showed that more than half of the clones in the library were affiliated to r ... | 2009 | 19403257 |
| treatment of polluted landscape lake water and community analysis of ammonia-oxidizing bacteria in constructed wetland. | three lab-scale horizontal subsurface flow constructed wetlands (hssf cws) were installed to demonstrate the use of constructed wetlands as a viable low-cost treatment option to purify the polluted scenery water. the goals of this study were to determine the effectiveness of the wetland treatment technology in reducing contaminants in polluted natural water body and to characterize bacterial composition present in 3 constructed wetlands. water samples were collected periodically for 12 months fr ... | 2009 | 19412855 |
| redundancy analysis demonstration of the relevance of temperature to ammonia-oxidizing bacterial community compositions in a full-scale nitrifying bioreactor treating saline wastewater. | although salt is known to influence the performance of nitrification significantly, it has not been well reported on how salt affects ammonia-oxidizing bacterial (aob) community compositions and dynamics in wastewater treatment bioreactors. in this study, these questions were evaluated in a full-scale bioreactor treating saline wastewater. clone library analysis for the ammonia monooxygenase subunit a gene revealed that aob belonging to the nitrosomonas europaea and the n. oligotropha lineages i ... | 2009 | 19420988 |
| effect of analgesics and their derivatives on antibiotic resistance of environmental microbes. | this research is a preliminary study conducted to determine the effects of aspirin (acetyl-salicylic acid) and salicylic acid (analgesics and their derivatives) on the antibiotic resistance of ammonia oxidizing bacterium (aob) (a non-pathogenic environmental microbe) cultured from the texas tech university-water recovery system that treats a space related wastewater for nasa. the effect of salicylic acid was investigated by obtaining the minimal inhibition concentration (mic) of antibiotics (amo ... | 2009 | 19448319 |
| chemoorganoheterotrophic growth of nitrosomonas europaea and nitrosomonas eutropha. | the ammonia oxidizers nitrosomonas europaea and nitrosomonas eutropha are able to grow chemoorganotrophically under anoxic conditions with pyruvate, lactate, acetate, serine, succinate, alpha-ketoglutarate, or fructose as substrate and nitrite as terminal electron acceptor. the growth yield of both bacteria is about 3.5 mg protein (mmol pyruvate)(-1) and the maximum growth rates of n. europaea and n. eutropha are 0.094 d(-1) and 0.175 d(-1), respectively. in the presence of pyruvate and co2 abou ... | 2009 | 19452213 |
| a soluble form of ammonia monooxygenase in nitrosomonas europaea. | ammonia monooxygenase (amo) of nitrosomonas europaea is a metalloenzyme that catalyzes the oxidation of ammonia to hydroxylamine. this study shows that amo resides in the cytoplasm of the bacteria in addition to its location in the membrane and is distributed approximately equally in both subcellular fractions. amo in both fractions catalyzes the oxidation of ammonia and binds [(14)c]acetylene, a mechanism-based inhibitor which specifically interacts with catalytically active amo. soluble amo wa ... | 2009 | 19453274 |
| life without light: microbial diversity and evidence of sulfur- and ammonium-based chemolithotrophy in movile cave. | microbial diversity in movile cave (romania) was studied using bacterial and archaeal 16s rrna gene sequence and functional gene analyses, including ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco), soxb (sulfate thioesterase/thiohydrolase) and amoa (ammonia monooxygenase). sulfur oxidizers from both gammaproteobacteria and betaproteobacteria were detected in 16s rrna, soxb and rubisco gene libraries. dna-based stable-isotope probing analyses using 13c-bicarbonate showed that thiobacill ... | 2009 | 19474813 |
| ammonia-oxidizing communities in a highly aerated full-scale activated sludge bioreactor: betaproteobacterial dynamics and low relative abundance of crenarchaea. | ammonia-oxidizing bacteria (aob) have long been considered key to the removal of nitrogen in activated sludge bioreactors. culture-independent molecular analyses have established that aob lineages in bioreactors are dynamic, but the underlying operational or environmental factors are unclear. furthermore, the contribution of ammonia-oxidizing archaea (aoa) to nitrogen removal in bioreactors has not been studied. to this end, we investigated the abundance of aoa and aob as well as correlations be ... | 2009 | 19515200 |
| diversity and abundance of ammonia-oxidizing bacteria in eutrophic and oligotrophic basins of a shallow chinese lake (lake donghu). | classical cultivation and molecular methods based on the ammonia monooxygenase gene (amoa) were used to study the abundance and diversity of beta-proteobacterial ammonia-oxidizing bacteria (aob) in lake sediments. the eutrophic and oligotrophic basins of a chinese shallow lake (lake donghu), in terms of ammonium (nh(+)(4)) concentrations, were sampled. the aob number was significantly lower in the oligotrophic basin, but significantly higher in the eutrophic basin. in addition, using restriction ... | 2009 | 19530312 |
| electricity production coupled to ammonium in a microbial fuel cell. | the production of electricity from ammonium was examined using a rotating-cathode microbial fuel cell (mfc). the addition of ammonium chloride, ammonium sulfate, or ammonium phosphate (monobasic) resulted in electricity generation, while adding sodium chloride, nitrate, or nitrite did not cause any increase in current production. the peak current increased with increasing amount of ammonium addition up to 62.3 mm of ammonium chloride, suggesting that ammonium was involved in electricity generati ... | 2009 | 19534163 |
| characterization of metabolites formed during the biotransformation of 17alpha-ethinylestradiol by nitrosomonas europaea in batch and continuous flow bioreactors. | the biotransformation of 17alpha-ethinylestradiol (ee2) by an ammonia oxidizing bacteria, nitrosomonas europaea, grown in batch (ammonia-rich) and continuous flow (chemostat, ammonia-limited) reactors was investigated. both c-14 labeled ee2 (10 gammag/l) and unlabeled ee2 (1 mg/l) were used to facilitate metabolite identification under environmentally relevant physiological conditions. whole cell ammonia monooxygenase (amo) activity was not inhibited at the ee2 concentrations used in this study. ... | 2009 | 19544853 |
| functional analysis of human rhcg: comparison with e. coli ammonium transporter reveals similarities in the pore and differences in the vestibule. | rh glycoproteins are members of the ammonium transporter (amt)/methylamine permease (mep)/rh family facilitating movement of nh(3) across plasma membranes. homology models constructed on the basis of the experimental structures of escherichia coli amtb and nitrosomonas europaea rh50 indicated a channel structure for human rha (rhag), rhb (rhbg), and rhc (rhcg) glycoproteins in which external and internal vestibules are linked by a pore containing two strictly conserved histidines. the pore entry ... | 2009 | 19553567 |
| [competition and optimization of aob and nob for domestic wastewater treatment at normal temperatures]. | at normal temperature of 19 degrees c +/- 1 degree c and seed sludge from the system of conventional nitrogen removal via nitrate composed of both ammonia oxidizing bacteria (aob) and nitrite oxidizing bacteria (nob), the competition and optimization of aob and nob was investigated in a lab-scale sbr treating domestic wastewater. the reactor was operated under the aeration rate of 40 l/h with the average do concentration below 1.0 mg/l, and combined with the control of aeration time, i.e., aerat ... | 2009 | 19558114 |
| [implement of completely autotrophic nitrogen removal in egsb reactor and its operation optimization]. | an expanded granular sludge bed (egsb) reactor inoculated simultaneously with aerobic ammonium oxidation sludge and anaerobic ammonium oxidation sludge were start-up to enrich completely autotrophic nitrogen removal granular sludge. total nitrogen (tn) removal rate reached 0.101 kg x (m3 x d)(-1). based on hypothesis of boundary layer, the transfer process between granular sludge and bulk liquid was modified, which was coupled with substance transfer process in granular sludge and aerobic ammoni ... | 2009 | 19558118 |
| [functional microbial community in a membrane-aerated biofilm reactor operated for completely autotrophic nitrogen removal]. | the 16s rdna-based molecular technique was applied to investigate the functional microbial community of a membrane-aerated biofilm bioreactor (mabr) that was used for completely autotrophic nitrogen removal over nitrite (canon). the relationships among two kinds of key bacteria responsible for canon: aerobic ammonia-oxidizing bacteria (aob) and anammox bacteria, and their possible distributions in the mab were discussed based on the microbial community analysis. fish analysis showed the existenc ... | 2009 | 19558119 |
| monochloramine disinfection kinetics of nitrosomonas europaea by propidium monoazide quantitative pcr and live/dead baclight methods. | monochloramine disinfection kinetics were determined for the pure-culture ammonia-oxidizing bacterium nitrosomonas europaea (atcc 19718) by two culture-independent methods, namely, live/dead baclight (ld) and propidium monoazide quantitative pcr (pma-qpcr). both methods were first verified with mixtures of heat-killed (nonviable) and non-heat-killed (viable) cells before a series of batch disinfection experiments with stationary-phase cultures (batch grown for 7 days) at ph 8.0, 25 degrees c, an ... | 2009 | 19561179 |
| expression of mera, trxa, amoa, and hao in continuously cultured nitrosomonas europaea cells exposed to cadmium sulfate additions. | the effects of cdso(4) additions on the gene expressions of a mercury reductase, mera, an oxidative stress protein, trxa, the ammonia-monooxygenase enzyme (amo), amoa, and the hydroxylamine oxidoreductase enzyme (hao), hao, were examined in continuously cultured n. europaea cells. the reactor was fed 50 mm nh(4)+ and was operated for 78 days with a 6.9 days hydraulic retention time. over this period, six successive batch additions of cdso(4) were made with increasing maximum concentrations rangi ... | 2009 | 19575436 |
| long-term operation of a partial nitritation pilot plant treating leachate with extremely high ammonium concentration prior to an anammox process. | the goal of this work was to demonstrate the feasibility of treating leachate with high ammonium concentrations using the sbr technology, as a preparative step for the treatment in an anammox reactor. the cycle was based on a step-feed strategy, alternating anoxic and aerobic conditions. results of the study verified the viability of this process, treating an influent with concentration up to 5000 mg n-nh(4)(+) l(-1). an effluent with about 1500-2000 mg n-nh(4)(+) l(-1) and 2000-3000 mg n-no(2)( ... | 2009 | 19577465 |
| nitrogen transformations and diversity of ammonia-oxidizing bacteria in a desert ephemeral stream receiving untreated wastewater. | levels of inorganic nitrogen species (ammonia, nitrite, and nitrate), ammonia oxidation potential (aop), and diversity of ammonia-oxidizing bacteria (aob) were studied in the sediments of a 50-km-long segment of an ephemeral stream in the negev desert, receiving untreated wastewater. water analysis in downstream sampling points showed reductions of 91.7% in biological oxygen demand, 87.7% in chemical oxygen demand, 73.9% in total nitrogen, and 72.8% in total ammonia nitrogen. significant aop lev ... | 2010 | 19593555 |
| fluctuation of microbial activities after influent load variations in a full-scale sbr: recovery of the biomass after starvation. | due to variations in the production levels, a full-scale sequencing batch reactor (sbr) for post-treatment of tannery wastewater was exposed to low and high ammonia load periods. in order to study how these changes affected the n-removal capacity, the microbiology of the reactor was studied by a diverse set of techniques including molecular tools, activity tests, and microbial counts in samples taken along 3 years. the recover capacity of the biomass was also studied in a lab-scale reactor opera ... | 2009 | 19629470 |
| effect of organic carbon on nitrification efficiency and community composition of nitrifying biofilms. | the effects of organic carbon/inorganic nitrogen (c/n) ratio on the nitrification processes and the community shifts of nitrifying biofilms were investigated by kinetic comparison and denaturing gradient gel electrophoresis (dgge) analysis. the results showed that the nitrification rate decreased with an increasing organic concentration. however, the effect became weak when the carbon concentration reached a sufficiently high level. denitrification was detected after organic carbon was added. th ... | 2009 | 19634453 |
| diversity and abundance of ammonia-oxidizing bacteria in eutrophic and oligotrophic basins of a shallow chinese lake (lake donghu). | classical cultivation and molecular methods based on the ammonia monooxygenase gene (amoa) were used to study the abundance and diversity of beta-proteobacterial ammonia-oxidizing bacteria (aob) in lake sediments. the eutrophic and oligotrophic basins of a chinese shallow lake (lake donghu), in terms of ammonium (nh(4)(+)) concentrations, were sampled. the aob number was significantly lower in the oligotrophic basin, but significantly higher in the eutrophic basin. in addition, using restriction ... | 2009 | 19640417 |
| [effect of ammonia-oxidizing bacteria (aob) on chloraminated disinfection attenuation in drinking water distribution system]. | the growth of microbe and formation of biofilm in water distribution system were important factors affecting the security of water quality. the number of ammonia-oxidizing bacteria (aob) in biofilm of a chloraminated drinking water distribution system in shanghai was detected by mpn-griess method, and the relations among aob, nitrification and chloraminated disinfection were analyzed. meanwhile, the effects of aob on chloraminated disinfection fastness and attenuation by simulation experiment we ... | 2009 | 19662845 |
| influence of intercropping and intercropping plus rhizobial inoculation on microbial activity and community composition in rhizosphere of alfalfa (medicago sativa l.) and siberian wild rye (elymus sibiricus l.). | alfalfa-siberian wild rye intercropping is the predominant cropping system used to produce forage in china. in this study, the effects of intercropping and intercropping-rhizobial inoculation on soil enzyme activities, microbial biomass and bacterial community composition in the rhizosphere were examined. in both treatments, the yield of alfalfa, microbial biomass and activities of soil urease, invertase and alkaline phosphatase in the alfalfa rhizosphere were markedly increased, whereas there w ... | 2009 | 19702874 |
| molecular characterization of microbial community in nitrate-removing activated sludge. | abstract the microbial community composition and dominant denitrifying populations in high-nitrate-removing (cr-i) and low-nitrate-removing (cr-ii) activated sludge from continuous bioreactors were investigated with most probable number (mpn) enumeration, fluorescence in situ hybridization (fish) and 16s rdna characterization. mpns of nitrate-reducing bacteria of sludge cr-i and sludge cr-ii were 2.82x10(7) and 2.69x10(4) colony-forming units ml(-1), respectively. eight denitrifying bacteria and ... | 2002 | 19709242 |
| nitrification in the schelde estuary: methodological aspects and factors influencing its activity. | abstract we present a 15-month dataset on nitrification measurements in the schelde estuary (belgium and the netherlands). nitrification was estimated using the n-serve sensitive dark (14)c-bicarbonate incorporation technique. a peak of nitrification activity was observed in the freshwater part of the estuary. downstream from this peak, nitrification declined, probably because of ammonium limitation. a range of nitrification inhibitors was tested on both a nitrosomonas europaea culture and estua ... | 2002 | 19709269 |
| high-rate partial nitrification performance of high ammonium containing wastewater under low temperatures. | in this study, a swim-bed reactor was used for partial nitrification treatment of magnesium ammonium phosphate precipitation process treated effluent of methane fermentation digester liquor. even without temperature, do, and ph control, the maximum nitrite production rate of 2.66 kg no(2)-n/m(3)/d was achieved under a nitrogen loading rate of 5.45 kg n/m(3)/d at 18 degrees c and a nitrite production rate of 0.22 kg no(2)-n/m(3)/d was still attained at a nitrogen loading rate of 0.48 kg n/m(3)/d ... | 2010 | 19709879 |
| nitrification-denitrification dynamics and community structure of ammonia oxidizing bacteria in a high yield irrigated philippine rice field. | nitrogen is the single most limiting factor for rice production. detailed knowledge on nitrogen dynamics in rice fields is therefore of major importance for developing sustainable rice production. a combination of state-of-the-art microsensor, stable isotope tracer, and molecular techniques was used to evaluate coupled nitrification-denitrification potentials and community structure of ammonia-oxidizing bacteria in a high yield irrigated rice cropping system in the philippines, without the use o ... | 2004 | 19712286 |
| autotrophic ammonia oxidation in a deep-sea hydrothermal plume. | direct evidence for autotrophic ammonia oxidation is documented for the first time in a deep-sea hydrothermal plume. elevated nh(4) (+) concentrations of up to 341+/-136 nm were recorded in the plume core at main endeavour field, juan de fuca ridge. this fueled autotrophic ammonia oxidation rates as high as 91 nm day(-1), or 92% of the total net nh(4) (+) removal. high abundance of ammonia-oxidizing bacteria was detected using fluorescence in situ hybridization. ammonia-oxidizing bacteria within ... | 2004 | 19712334 |
| acetylene and oxygen as inhibitors of nitrous oxide production in nitrosomonas europaea and nitrosospira briensis: a cautionary tale. | autotrophic ammonia-oxidizing bacteria produce nitrous oxide (n(2)o) as a by-product of nitrification or as an intermediate of nitrifier denitrification. in soil incubations, acetylene (c(2)h(2)) and large partial pressures of oxygen (o(2)) are used to distinguish between these sources. c(2)h(2) inhibits ammonia oxidation and should therefore inhibit n(2)o production by both nitrification and nitrifier denitrification. o(2) suppresses the reduction pathway of nitrifier denitrification. however, ... | 2004 | 19712342 |
| composition and diversity of ammonia-oxidising bacterial communities in wastewater treatment reactors of different design treating identical wastewater. | autotrophic ammonia-oxidising bacteria (aob) are a crucial component of the microbial communities of nitrifying wastewater treatment systems. nitrification is known to occur in reactors of different configuration, but whether aob communities are different in reactors of different design is unknown. we compared the diversity and community structure of the betaproteobacterial aob in two full-scale treatment reactors - a biological aerated filter (baf) and a trickling filter - receiving the same wa ... | 2003 | 19719680 |
| application of temperature gradient gel electrophoresis to the characterization of a nitrifying bioaugmentation product. | the microbial population of a nitrifying bioaugmentation product (nbp) has been examined using a combination of conventional bacteriological methods and modern molecular techniques. variable region 3 (v3) of the 16s rrna genes of the bacteria in nbp was amplified via the polymerase chain reaction (pcr) with universal eubacterial primers and analyzed via temperature gradient gel electrophoresis (tgge). two of the predominant pcr products in nbp were purified from the tgge gel matrix, reamplified ... | 2003 | 19719689 |
| characterization of a microbial community capable of nitrification at cold temperature. | while the oxidation of ammonia is an integral component of advanced aerobic livestock wastewater treatment, the rate of nitrification by ammonia-oxidizing bacteria is drastically reduced at colder temperatures. in this study we report an acclimated lagoon nitrifying sludge that is capable of high rates of nitrification at temperatures from 5 degrees c (11.2mg n/g mlvss/h) to 20 degrees c (40.4 mg n/g mlvss/h). the composition of the microbial community present in the nitrifying sludge was invest ... | 2010 | 19734046 |
| ccpa from geobacter sulfurreducens is a basic di-heme cytochrome c peroxidase. | bacterial di-heme cytochrome c peroxidases (ccpas) protect the cell from reactive oxygen species by reducing hydrogen peroxide to water. the enzymes are c-type cytochromes, with both heme groups covalently attached to the protein chain via a characteristic binding motif. the genome of the dissimilatory metal-reducing bacterium geobacter sulfurreducens revealed the presence of a ccpa gene and we isolated the gene product after recombinant expression in escherichia coli. ccpa from g. sulfurreducen ... | 2009 | 19735665 |
| biodegradation potential of wastewater micropollutants by ammonia-oxidizing bacteria. | this study examined the biodegradation potential of three wastewater micropollutants (triclosan, bisphenol a, and ibuprofen) by nitrosomonas europaea and mixed ammonia-oxidizing bacteria in nitrifying activated sludge. n. europaea could degrade triclosan and bisphenol a, but not ibuprofen. the degradation was observed only in the absence of allylthiourea (an inhibitor for ammonia monooxygenase (amo)), suggesting that amo might be responsible for triclosan and bisphenol a degradation. competitive ... | 2009 | 19772981 |
| [research on canon process for municipal sewage in room temperature]. | in the room temperature 14.7-24.7 degrees c, simultaneous nitrification-anammox (canon) process for municipal sewage was tested by sbr while the do was controlled between 0.05 and 0.30 mg/l. as a result, the research shows that canon process can be applied to the nitrogen treatment of municipal wastewater in room temperature by sbr. do can be regarded as the indication parameter of reaction terminal, and 1 mg/l has been confirmed in the experiment. in the exploring sbr experiments, the consumpti ... | 2009 | 19774999 |
| [community structure and kinetics characterization of enriched nitrifiers cultivated with reject water]. | the community of nitrifiers cultivated with reject water were investigated by fluorescent in situ hybridization (fish) performed with 16s rrna-targeted oligonucleotide probes, and the kinetic properties such as temperature correction factor taun and the half saturation coefficient k(n) were also investigated. the results showed that the percentage of ammonia oxidizing bacteria (aob) and nitrite oxidizing bacteria (nob) in the activated sludge was 15.7% +/- 3.7% and 12.9% +/- 3.2%, nitrosomonas e ... | 2009 | 19775004 |
| altitude ammonia-oxidizing bacteria and archaea in soils of mount everest. | to determine the abundance and distribution of bacterial and archaeal ammonia oxidizers in alpine and permafrost soils, 12 soils at altitudes of 4000-6550 m above sea level (m a.s.l.) were collected from the northern slope of the mount everest (tibetan plateau), where the permanent snow line is at 5800-6000 m a.s.l. communities were characterized by real-time pcr and clone sequencing by targeting on amoa genes, which putatively encode ammonia monooxygenase subunit a. archaeal amoa abundance was ... | 2009 | 19780828 |
| ammonia oxidation kinetics determine niche separation of nitrifying archaea and bacteria. | the discovery of ammonia oxidation by mesophilic and thermophilic crenarchaeota and the widespread distribution of these organisms in marine and terrestrial environments indicated an important role for them in the global nitrogen cycle. however, very little is known about their physiology or their contribution to nitrification. here we report oligotrophic ammonia oxidation kinetics and cellular characteristics of the mesophilic crenarchaeon 'candidatus nitrosopumilus maritimus' strain scm1. unli ... | 2009 | 19794413 |
| evidence for biological nitrification inhibition in brachiaria pastures. | nitrification, a key process in the global nitrogen cycle that generates nitrate through microbial activity, may enhance losses of fertilizer nitrogen by leaching and denitrification. certain plants can suppress soil-nitrification by releasing inhibitors from roots, a phenomenon termed biological nitrification inhibition (bni). here, we report the discovery of an effective nitrification inhibitor in the root-exudates of the tropical forage grass brachiaria humidicola (rendle) schweick. named "br ... | 2009 | 19805171 |
| effects of oxygenation on ammonia oxidation potential and microbial diversity in sediment from surface-flow wetland mesocosms. | addition of oxygen to surface-flow wetland mesocosms treating synthetic secondary effluent resulted in a significant increase in ammonia oxidation potential in sediment compared to non-oxygenated controls. ammonia oxidation potential in oxygenated wetland sediment (1.2-3.5 mg n g dw(-1) d(-1)) was 2-3 orders of magnitude higher than those measured in sediment and soil systems reported in the literature. phylogenic analysis of sediment from the two treatments revealed substantial differences in m ... | 2010 | 19815408 |
| the presence of an endogenous respiration in the autotrophic bacteria. | it is shown that there exists in the autotrophic bacterium thiobacillus thiooxidans a measurable oxygen uptake in the absence of the specific nutrient (sulfur). this respiration is shown to be due to the utilization of organic materials which must have been previously synthesized by the chemosynthetic process, providing evidence that autotrophic bacteria contain a dissimilatory process which involves the breakdown of organic materials and furnishes energy for the maintenance of the cell during p ... | 1942 | 19873300 |
| nitrification in fixed-bed reactors treating saline wastewater. | halophilic nitrifiers belonging to the genus nitrosomonas and nitrospira were enriched from seawater and marine sediment samples of the north sea. the maximal ammonia oxidation rate (aor) in batch enrichments with seawater was 15.1 mg n l(-1) day(-1). an intermediate nitrite accumulation was observed. two fixed-bed reactors for continuous nitrification with either polyethylene/claysinter lamellas (fbr a) or porous ceramic rings (fbr b)were run at two different ammonia concentrations, three diffe ... | 2010 | 19915833 |
| population dynamics of nitrite oxidizers in nitrifying granules. | the competition between nitrospira and nitrobacter species was analyzed in this work under conditions of excess of nitrite. a population of nitrite oxidizing bacteria (nob) was developed from nitrifying biomass grown as granules with a mean diameter of 0.8 mm, whose feed was switched from ammonium to nitrite. the initial population distribution of the granules was: 60% nitrosomonas and 30% nitrospira and it evolved to 45% nitrobacter and 40% nitrospira measured 177 days after the change in the f ... | 2009 | 19923758 |
| ammonia oxidizing bacteria community in activated sludge monitored by denaturing gradient gel electrophoresis (dgge). | biological treatment based on activated sludge is efficient in municipal wastewater treatment. the removal of nitrogen compounds is crucial for sewage purification. due to the fact that ammonia is toxic for a water environment and causes eutrophication, ammonia oxidation is of the utmost importance in wastewater treatment. observing the changeability of ammonia oxidizing bacteria (aob) and identifying their most abundant species can be helpful in the optimization of wastewater treatment. in this ... | 2009 | 19940383 |
| [community structures of ammonia-oxidizing bacteria in activated sludge of wastewater treatment plants]. | in order to investigate the community structure of ammonia oxidizing bacteria (aob) in wastewater treatment plants and the influence of treatment process and system scale on aob community. we investigated aob communities in activated sludges collected from 9 wastewater treatment systems, using specific pcr followed by terminal restriction fragment length polymorphism (t-rflp), cloning, and sequencing of amoa genes. the t-rflp fingerprints analysis shows that there are some differences among the ... | 2009 | 19968121 |
| characteristics of the microbial communities in the integrated vertical-flow constructed wetlands. | microorganisms play an important role in removing pollutants from constructed wetlands. we investigated the microbial characteristics in a novel integrated vertical-flow constructed wetland (ivcw), which has been in operation in wuhan, china since 1998. we used phospholipid fatty acid (plfa) and amoa gene to analyze the structure and diversity of the microbial community within the ivcw. plfa results suggested that the amount of bacterial plfa was significantly higher than that of fungal plfa, bu ... | 2009 | 19999975 |
| operation of suspended-growth shortcut biological nitrogen removal (ssbnr) based on the minimum/maximum substrate concentration. | this study exploited the concept of the minimum/maximum substrate concentrations (msc values) for identifying proper start-up conditions and achieving stable and low effluent total ammonium nitrogen (tan) concentrations in suspended-growth short-cut biological nitrogen removal (ssbnr). calculations based on the msc concept indicated that s(dmax), the tan concentration above which ammonium-oxidizing bacteria (aob) are washed out, was around 450mgtan/l at the given operating conditions of 2mg/l of ... | 2010 | 20004929 |
| source of nitrous oxide emissions during the cow manure composting process as revealed by isotopomer analysis of and amoa abundance in betaproteobacterial ammonia-oxidizing bacteria. | a molecular analysis of betaproteobacterial ammonia oxidizers and a n(2)o isotopomer analysis were conducted to study the sources of n(2)o emissions during the cow manure composting process. much no(2)(-)-n and no(3)(-)-n and the nitrosomonas europaea-like amoa gene were detected at the surface, especially at the top of the composting pile, suggesting that these ammonia-oxidizing bacteria (aob) significantly contribute to the nitrification which occurs at the surface layer of compost piles. howe ... | 2010 | 20048060 |
| crystallization and preliminary x-ray crystallographic analysis of a new crystal form of hydroxylamine oxidoreductase from nitrosomonas europaea. | hydroxylamine oxidoreductase (hao) from nitrosomonas europaea is a homotrimeric protein that catalyzes the oxidation of hydroxylamine to nitrite. each monomer, with a molecular weight of 67.1 kda, contains seven c-type hemes and one heme p460, the porphyrin ring of which is covalently linked to a tyrosine residue from an adjacent subunit. hao was first crystallized and structurally characterized at a resolution of 2.8 a in 1997. the structure was solved in space group p6(3) and suffered from mer ... | 2009 | 20054133 |
| enrichment of marine anammox bacteria from seawater-related samples and bacterial community study. | anaerobic ammonium oxidation (anammox) is a novel nitrogen pathway catalyzed by anammox bacteria which are obligate anaerobic chemoautotrophs. in this study, enrichment culture of marine anammox bacteria (maaob) from the samples related to seawater was conducted. simultaneous removal of ammonium and nitrite was confirmed in continuous culture inoculated with sediment of a sea-based waste disposal site within 50 days. however, no simultaneous nitrogen removal was observed in cultures inoculated w ... | 2010 | 20057097 |
| [nitrous oxide fluxes of constructed wetlands to treat sewage wastewater]. | the nitrous oxide fluxes and ammonia-oxidizing bacterium in two typical constructed wetlands, i.e. subsurface flow (sf) and free water surface (fws) were studied by the method of static chamber-gas chromatography. the results showed that the mean n2o fluxes were 296.5 microg x (m2 x h)(-1) and 28.2 microg x (m2 x h)(-1) respectively, and two typical wetlands were all the sources of atmosphere nitrous oxide as a whole. sf wetland exhibited a higher risk of n2o emissions, and the mean n2o flux in ... | 2009 | 20063721 |
| stability of partial nitrification and microbial population dynamics in a bioaugmented membrane bioreactor. | bioaugmentation of bioreactors focuses on the removal of numerous organics, with little attention typically paid to the maintenance of high and stable nitrite accumulation in partial nitrification. in this study, a bioaugmented membrane bioreactor (mbr) inoculated with enriched ammonia-oxidizing bacteria (aob) was developed, and the effects of dissolved oxygen (do) and temperature on stability of partial nitrification and microbial community structure, in particular on nitrifying community were ... | 2009 | 20075634 |
| municipal landfill leachate nitrification in rbc biofilm - process efficiency and molecular analysis of microbial structure. | landfill leachates were treated using a two-stage rotating biological contactor (rbc). at an ammonium load of 1.92gn-nh(4)/m(2)d, complete nitrification was obtained at the first stage; however, at a higher load (3.6gn-nh(4)/m(2)d) a two-stage system was needed to obtain complete nitrification. a further increase in the ammonium load to 4.79gn-nh(4)/m(2)d and 6.63gn-nh(4)/m(2)d caused a decrease of overall nitrification efficiency to 74.4% and 71.6%, respectively. randomly amplified dna analysis ... | 2010 | 20110168 |
| partial nitrification treatment for high ammonium wastewater from magnesium ammonium phosphate process of methane fermentation digester liquor. | this study investigated partial nitrification treatment of methane fermentation digester liquor effluent from magnesium ammonium phosphate precipitation process in a swim-bed reactor. the reactor was operated at a temperature of 35 degrees c and ph between 7.5 and 7.8. partial nitrification was achieved at the onset of the experiments even though conventional activated sludge was used as seed sludge. the maximum nitrite production rate was 1.0 kg no(2)-n/m(3)/d at a nitrogen loading rate of 2.0 ... | 2010 | 20129095 |
| nitrification and degradation of halogenated hydrocarbons--a tenuous balance for ammonia-oxidizing bacteria. | the process of nitrification has the potential for the in situ bioremediation of halogenated compounds provided a number of challenges can be overcome. in nitrification, the microbial process where ammonia is oxidized to nitrate, ammonia-oxidizing bacteria (aob) are key players and are capable of carrying out the biodegradation of recalcitrant halogenated compounds. through industrial uses, halogenated compounds often find their way into wastewater, contaminating the environment and bodies of wa ... | 2010 | 20146060 |
| molecular biological characterization and biostimulation of ammonia-oxidizing bacteria in brackishwater aquaculture. | in the present study, molecular methods based on sequencing of clone libraries have been used to provide sequence and the phylogenetic information of ammonia oxidizing bacteria (aob). ammonia monooxygenase (amoa) gene, which catalyzed the oxidation of ammonia to hydroxyl amine in the initial rate-determining step of nitrification was targeted for detection and characterization of aob using gene-specific primers. the amoa genes obtained through the clone library construction are closely affiliate ... | 2009 | 20183519 |
| autotrophic nitrogen removal discovered in suspended nitritation system. | a lab-scale sequencing batch reactor was operated in batch mode to treat ammonium-rich synthetic wastewater, and minor n loss (about 9%) was observed without seeding anaerobic ammonium oxidation bacteria (anaob). around 4 wk after the dissolved oxygen concentration was decreased (from 0.9+/-0.1 to 0.4+/-0.1 mg l(-1)) and the hydraulic retention time was elevated (from 11.0 to 14.7 h), 80% of total nitrogen removal efficiency and 0.49 kg n m(-3) d(-1) of maximum nitrogen removal capacity were obt ... | 2010 | 20188394 |