| energy model and metabolic flux analysis for autotrophic nitrifiers. | the behavior of pure cultures of nitrifying microorganisms under autotrophic growth operating conditions was investigated and the relations between their energy metabolism and their anabolism analyzed by means of metabolic network computation. the description of the metabolism of the nitrifiers is extended to their energy metabolism by introducing compartmentalization (cytoplasmic and periplasmic sides) and studying coupling between the electron transport chain and the proton gradient generation ... | 2001 | 11180062 |
| structure and activity of multiple nitrifying bacterial populations co-existing in a biofilm. | a biofilm from a nitrifying pilot-scale sequencing batch reactor was investigated for effects of varying process conditions on its microscale activity and structure. microsensor measurements of oxygen, substrates and products of nitrification were applied under incubation at different ammonium and oxygen concentrations which reflected various situations during a treatment cycle. a high net n loss was observed under high ammonium (ha) concentrations in contrast to low ones. additionally, results ... | 2003 | 12713462 |
| phylogenetic and dna-dna hybridization analyses of bradyrhizobium species. | the 16s rdna sequence of bradyrhizobium liaoningense was determined and analysed together with sequences of other bradyrhizobium species and related taxa. in addition, dna-dna hybridizations were performed between representative strains of the three bradyrhizobium species. bradyrhizobium liaoningense is genotypically highly related to bradyrhizobium japonicum, whereas bradyrhizobium elkanii is more distantly related to these two species. the fact that afipia, agromonas, blastobacter, nitrobacter ... | 2001 | 11211247 |
| minimum phosphate and magnesium requirements of nitrifying bacteria. | | 1952 | 13013339 |
| [the relation of oxidized nitrogen to the reduced carbon in nitrobacter]. | | 1954 | 13171874 |
| [on nitrite oxidation by nitrobacter winogradskyi]. | | 1954 | 13229327 |
| [physiology and biochemistry of nitrifying micro-organisms]. | | 1956 | 13321534 |
| [nitrite oxidation by nitrobacter vinogradskii buch. and its relation to weather factors]. | | 1956 | 13340834 |
| ferrobacillus ferrooxidans: a chemosynthetic autotrophic bacterium. | | 1956 | 13376518 |
| the biochemistry of the nitrifying organisms. v. nitrite oxidation by nitrobacter. | | 1957 | 13403908 |
| [problem of nitrite oxidation with supplementary co2 assimilation in nitrobacter winogradskii buch]. | | 1957 | 13522131 |
| cytochromes of nitrobacter. | | 1958 | 13590096 |
| cell-free nitrification by nitrobacter. | | 1958 | 13598710 |
| [agents initiating the second phase of nitrification. ii. effect of heavy metals on nitrification]. | | 1958 | 13622243 |
| [organism inducing the second phase of nitrification. iii. morphology of the organism inducing the second phase of nitrification]. | | 1958 | 13632414 |
| nitrite oxidation by nitrobacter in the presence of certain nitrophenols. | | 1960 | 13689460 |
| the biochemistry of the nitrifying organisms. 6. the effect of oxygen concentration on nitrite oxidation in the presence of different inorganic ions. | | 1960 | 13689461 |
| the biochemistry of the nitrifying organisms. 7. the phosphate compounds of nitrobacter and the uptake of orthophosphate by the organism. | | 1960 | 13689462 |
| [the assimilation of carbon dioxide by nitrobacter winogradskyi]. | | 1961 | 13755762 |
| [photoinactivation of nitrobacter winogradskyi buch]. | | 1961 | 13773574 |
| on the excitant of the 2nd phase of nitrification. iv. dehydrogenase activity of the washed suspension of nitrobacter winogradsky buch | | 1960 | 13788009 |
| nutrition and physiology of nitrobacter agilis. | | 1960 | 13792492 |
| the isolation and culture of the nitrifying organisms. part i. nitrobacter. | | 1960 | 13828576 |
| [on the effect of hydrocyanic acid on chemical synthesis]. | | 1961 | 13830946 |
| [research on chemical synthesis]. | | 1961 | 13830947 |
| the morphology of nitrobacter winogradskyi. | | 1959 | 13847099 |
| [the gross equation of carbon dioxide-assimilation of nitrobacter winogradskyi buch]. | | 1959 | 13849711 |
| use of electron paramagnetic resonance spectroscopy in investigations of functional metal components in micro-organisms. | | 1962 | 13938326 |
| kinetics of nitrite oxidation by nitrobacter winogradskyi. | | 1962 | 14013807 |
| [on the mechanism of chemosynthesis]. | | 1962 | 14037073 |
| [on the mechanism of chemosynthesis. on the "residual respiration" of chemoautotrophic nitrobacter winogradskyi]. | | 1963 | 14042164 |
| [bacterial associations and biological alterations of limestone monuments]. | | 1963 | 14048726 |
| adenosine triphosphate-dependent reduction of nicotinamide adenine dinucleotide by ferro-cytochrome c in chemoautotrophic bacteria. | | 1963 | 14087009 |
| [on the reduction of diphosphopyridine nucleotide in chemo-synthesis]. | | 1963 | 14087312 |
| [the behavior of nitrobacter winogradskyi buch. towards increased co2 partial pressure]. | | 1964 | 14134892 |
| microenvironments and distribution of nitrifying bacteria in a membrane-bound biofilm. | the distribution of nitrifying bacteria of the genera nitrosomonas, nitrosospira, nitrobacter and nitrospira was investigated in a membrane-bound biofilm system with opposed supply of oxygen and ammonium. gradients of oxygen, ph, nitrite and nitrate were determined by means of microsensors while the nitrifying populations along these gradients were identified and quantified using fluorescence in situ hybridization (fish) in combination with confocal laser scanning microscopy. the oxic part of th ... | 2000 | 11214800 |
| development of nitrification inhibition assays using pure cultures of nitrosomonas and nitrobacter. | restricted requirements for nitrogen reduction at wastewater treatment plants have increased the need for assays determining the inhibition of nitrification. in this paper, two new assays studying ammonia oxidation and nitrite oxidation, respectively, are presented. as test organisms, pure cultures of nitrosomonas and nitrobacter isolated from activated sludge are used. the assays are performed in test tubes where the bacteria are incubated with the compound or wastewater to be tested. the nitri ... | 2001 | 11228996 |
| microbiology of a nitrite-oxidizing bioreactor. | the microbiology of the biomass from a nitrite-oxidizing sequencing batch reactor (nosbr) fed with an inorganic salts solution and nitrite as the sole energy source that had been operating for 6 months was investigated by microscopy, by culture-dependent methods, and by molecular biological methods, and the seed sludge that was used to inoculate the nosbr was investigated by molecular biological methods. the nosbr sludge comprised a complex and diverse microbial community containing gram-negativ ... | 1998 | 9572966 |
| evolutionary relationships among ammonia- and nitrite-oxidizing bacteria. | comparative 16s rrna sequencing was used to evaluate phylogenetic relationships among selected strains of ammonia- and nitrite-oxidizing bacteria. all characterized strains were shown to be affiliated with the proteobacteria. the study extended recent 16s rrna-based studies of phylogenetic diversity among nitrifiers by the comparison of eight strains of the genus nitrobacter and representatives of the genera nitrospira and nitrospina. the later genera were shown to be affiliated with the delta s ... | 1994 | 7961414 |
| combined molecular and conventional analyses of nitrifying bacterium diversity in activated sludge: nitrosococcus mobilis and nitrospira-like bacteria as dominant populations. | the ammonia-oxidizing and nitrite-oxidizing bacterial populations occurring in the nitrifying activated sludge of an industrial wastewater treatment plant receiving sewage with high ammonia concentrations were studied by use of a polyphasic approach. in situ hybridization with a set of hierarchical 16s rrna-targeted probes for ammonia-oxidizing bacteria revealed the dominance of nitrosococcus mobilis-like bacteria. the phylogenetic affiliation suggested by fluorescent in situ hybridization (fish ... | 1998 | 9687471 |
| identification and activities in situ of nitrosospira and nitrospira spp. as dominant populations in a nitrifying fluidized bed reactor. | bacterial aggregates from a chemolithoautotrophic, nitrifying fluidized bed reactor were investigated with microsensors and rrna-based molecular techniques. the microprofiles of o2, nh4+, no2-, and no3- demonstrated the occurrence of complete nitrification in the outer 125 microgram of the aggregates. the ammonia oxidizers were identified as members of the nitrosospira group by fluorescence in situ hybridization (fish). no ammonia- or nitrite-oxidizing bacteria of the genus nitrosomonas or nitro ... | 1998 | 9726900 |
| water quality management for low temperature marine fishes in space. | vestibular function experiment unit (vfeu), one of the spacelab facility flown in neurolab mission (sts-90) in april, 1998, was to support neurophysiological research using a marine fish, opsanus tau (oyster toadfish). the functions of the vfeu were primarily a quality management of environmental water during the mission at 14 degrees c and for acquiring physiological signals from implanted micro-electrodes in the otolith nerves as well as the spatial acceleration of the fish. a key element of t ... | 1999 | 11542798 |
| r&d of long-term life support system by using electrochemically activated biofilm reactor of aquatic animals for space examinations. | we have developed the long-term life support system that enables the experiment of aquatic animals breeding for 90 days or more for the future experiments in orbit. in order to enable long-term breeding of wide aquatic animals, it is necessary to remove nitrate produced by biological nitrification. then, we examined a denitrification method to use an electrochemical reaction of biofilm-electrode reactor. in this research, we have not kept the aquatic animals actually but imitated breeding of fiv ... | 1999 | 11542801 |
| ammonia-oxidizing bacteria: a model for molecular microbial ecology. | the eutrophication of many ecosystems in recent decades has led to an increased interest in the ecology of nitrogen transformation. chemolitho-autotrophic ammonia-oxidizing bacteria are responsible for the rate-limiting step of nitrification in a wide variety of environments, making them important in the global cycling of nitrogen. these organisms are unique in their ability to use the conversion of ammonia to nitrite as their sole energy source. because of the importance of this functional grou ... | 2001 | 11544365 |
| potential nitrification rate as a tool for screening toxicity in metal-contaminated soils. | a potential nitrification rate test (pnr) was used to identify metal toxicity in field-contaminated soils. the test was applied to metal salt-spiked soils, to 27 uncontaminated soils, and to 15 soils that are contaminated by former metal smelting activities. four agricultural soils (ph 4.5-6.6) were spiked with various rates of cdcl2 (0-200 mg cd/kg dry wt) or zncl2 (0-3,000 mg cd/kg dry wt) and were equilibrated more than nine months prior to testing. the soil zn ec50s of the pnr were between 1 ... | 2001 | 11699771 |
| ammonia- and nitrite-oxidizing bacterial communities in a pilot-scale chloraminated drinking water distribution system. | nitrification in drinking water distribution systems is a common operational problem for many utilities that use chloramines for secondary disinfection. the diversity of ammonia-oxidizing bacteria (aob) and nitrite-oxidizing bacteria (nob) in the distribution systems of a pilot-scale chloraminated drinking water treatment system was characterized using terminal restriction fragment length polymorphism (t-rflp) analysis and 16s rrna gene (ribosomal dna [rdna]) cloning and sequencing. for ammonia ... | 2002 | 11772611 |
| the canon system (completely autotrophic nitrogen-removal over nitrite) under ammonium limitation: interaction and competition between three groups of bacteria. | the canon system (completely autotrophic nitrogen removal over nitrite) can potentially remove ammonium from wastewater in a single, oxygen-limited treatment step. the usefulness of canon as an industrial process will be determined by the ability of the system to recover from major disturbances in feed composition. the canon process relies on the stable interaction between only two bacterial populations: nitrosomonas-like aerobic and planctomycete-like anaerobic ammonium oxidising bacteria. the ... | 2001 | 11876366 |
| immunological detection of nitrospira-like bacteria in various soils. | chemolithotrophic nitrite oxidizers were enriched from five different soils including freshwater marsh, permafrost, garden, agricultural, and desert soils and monitored during the cultivation procedure. immunoblot analysis was used to identify the nitrite oxidizing organisms with monoclonal antibodies, which recognize the key enzyme of nitrite oxidation in a genus-specific reaction [bartosch et al. (1999) appl environ microbiol 65:4126-4133]. the morphological characteristics of the enriched nit ... | 2002 | 11984626 |
| intestinal urea metabolism: could the bacteria involved in nitrogen cycle lead to reutilization of intestinal urea nitrogen in uremic rabbits? | we aimed to evaluate the effect of bacteria involved in the nitrogen cycle on the reutilization of intestinal urea nitrogen in uremic rabbits. new zealand white rabbits were made uremic via bilateral nephrectomy. study and control rabbits were given live and heat-inactivated bacteria through their jejunostomies. after they were injected with 99mtc biurea intravenously, serial serum and stool levels of labeled nitrogen were assessed by instant thin-layer chromatography, and the change in the labe ... | 2002 | 12026184 |
| high mortality in zebrafish (danio rerio). | a group of 100 adult zebrafish were housed in a new system at a stocking density of 20 fish per tank. four weeks after arrival, 15 fish presented with petechial hemorrhages and ulceration on the surfaces of the skin. samples of the fish were collected for histopathology, fungal culture, and bacterial culture and sensitivity. water samples were analyzed for ph, ammonia, nitrite, and submitted for bacterial and fungal culture. histologically, the epidermis had multiple areas of ulceration and mono ... | 1999 | 12086431 |
| tfda-like genes in 2,4-dichlorophenoxyacetic acid-degrading bacteria belonging to the bradyrhizobium-agromonas-nitrobacter-afipia cluster in alpha-proteobacteria. | the 2,4-dichlorophenoxyacetate (2,4-d)/alpha-ketoglutarate dioxygenase gene (tfda) homolog designated tfdaalpha was cloned and characterized from 2,4-d-degrading bacterial strain rd5-c2. this japanese upland soil isolate belongs to the bradyrhizobium-agromonas-nitrobacter-afipia cluster in the alpha subdivision of the class proteobacteria on the basis of its 16s ribosomal dna sequence. sequence analysis showed 56 to 60% identity of tfdaalpha to representative tfda genes. a male-tfdaalpha fusion ... | 2002 | 12089027 |
| use of natural zeolite to enhance nitrification in biofilter. | to enhance nitrification, natural zeolite and activated carbon were tested as a media in a biofilter to treat wastewater containing relatively high concentrations of tkn. using those media, the adsorption isotherms for ammonium ion were compared; the k values for natural zeolite and activated carbon were found to be 0.5117 and 0.0006, respectively. in comparison of the performance of the two media, two identical, lab-scale biofilters were then operated for 4 months. the effect of nh3-n loading r ... | 2002 | 12164639 |
| go or no go for gel entrapped nitrifiers? a belgian case study. | in the coming years, as stricter environmental requirements are imposed, many european union wastewater treatment plants (wwtp) need to be expanded and/or upgraded. this requires considerable investments. optimising the renovation recourses can lead to significant savings. the use of entrapped nitrifying bacteria for upgrading of wwtp towards nutrient removal may be benificial. long term pilot tests were performed to evaluate a so-called pellet reactor. differences in performance and microbiolog ... | 2002 | 12216669 |
| use of polyclonal antibodies to detect and quantify the nor protein of nitrite oxidizers in complex environments. | in the approaches or models which aim to understand and/or predict how the functioning of ecosystems may be affected by perturbations or disturbances, little attention is generally given to microorganisms. even when they are taken into account as indicators, variables which are poorly informative about the changes in the microbial functioning (microbial biomass or diversity or total number of microorganisms) are often used. to be able to estimate, in complex environments, the quantity of enzymes ... | 2003 | 12609727 |
| biological treatment process of air loaded with an ammonia and hydrogen sulfide mixture. | the physico-chemical characteristics of granulated sludge lead us to develop its use as a packing material in air biofiltration. then, the aim of this study is to investigate the potential of unit systems packed with this support in terms of ammonia and hydrogen sulfide emissions treatment. two laboratory scale pilot biofilters were used. a volumetric load of 680 g h2s m(-3) empty bed day(-1) and 85 g nh3 m(-3) empty bed day(-1) was applied for eight weeks to a unit called bgsn (column packed wi ... | 2003 | 12656240 |
| susceptibility of ammonia-oxidizing bacteria to nitrification inhibitors. | activity of nitrification inhibitors to several typical ammonia-oxidizing bacteria isolated recently, i. e. nitrosococcus, nitrosolobus, nitrosomonas, nitrosospira and nitrosovibrio species was assayed using 2-amino-4-methyl-trichloromethyl-1,3,5-triazine (mast), 2-amino-4-tribromomethyl-6-trichloromethyl-1,3,5-triazine (br-mast), 2-chloro-6-trichloromethylpyridine (nitrapyrin) and others, and compared to confirm the adequate control of ammonia-oxidizing bacteria by the inhibitors. the order of ... | 2003 | 12710742 |
| changing concepts in the systematics of bacterial nitrogen-fixing legume symbionts. | as of february 2003, bacteria that form nitrogen-fixing symbiotic associations with legumes have been confirmed in 44 species of 12 genera. phylogenies of these taxa containing legume symbionts based on the comparative analysis of 16s rdna sequences show that they are not clustered in one lineage but are distributed in the classes alphaproteobacteria and betaproteobacteria, and dispersed over the following nine monophyletic groups, being intermingled with other taxa that do not contain legume sy ... | 2003 | 12949698 |
| iron metabolism in rhodobacter capsulatus. characterisation of bacterioferritin and formation of non-haem iron particles in intact cells. | the water-soluble cytochrome b557 from the photosynthetic bacterium rhodobacter capsulatus was purified and shown to have the properties of the iron-storage protein bacterioferritin. the molecular mass of r. capsulatus bacterioferritin is 428 kda and it is composed of a single type of 18-kda subunit. the n-terminal amino acid sequence of the bacterioferritin subunit shows 70% identity to the sequence of bacterioferritin subunits from escherichia coli, nitrobacter winogradskyi, azotobacter vinela ... | 1994 | 8055962 |
| vfeu water quality control in sts-95 mission. | in sts-95 space shuttle mission, an aquatic animal research facility, vestibular function experiment unit (vfeu), was flown to perform neurobiological experiment with marine fish, oyster toadfish. for this purpose, we have developed a sea water purification system using highly active nitrifying bacteria at low temperature. with this system, the water quality in the vfeu was maintained in sufficient condition to keep the toadfish in healthy state for 9 days of the mission. this report summarizes ... | 1999 | 11542797 |
| [apropos of nitrate reductases of a denitrifying bacterium]. | | 1964 | 14205501 |
| on the assimilation of energy from inorganic sources in autotrophic forms of life. | | 1964 | 14224403 |
| the biochemistry of the nitrifying organisms. 8. the effects of oxygen tension, nitrite concentration, and cyanate concentration on nitrite oxidation by nitrobacter. | | 1964 | 14228219 |
| [the behavior of nitrifying bacteria towards dissolved oxygen]. | | 1964 | 14245150 |
| molybdenum as a micronutrient for nitrobacter. | finstein, m. s. (university of california, davis), and c. c. delwiche. molybdenum as a micronutrient for nitrobacter. j. bacteriol. 89:123-128. 1965.-the requirement of nitrobacter for molybdenum was investigated by use of a medium purified by chemical means, as well as by depletion by the prior growth of this autotrophic bacterium. during 5 days of growth, added molybdenum induced an approximately 11-fold increase in both nitrite utilization and cell-mass development. in short-term studies, max ... | 1965 | 14255651 |
| characterization of a nitrate reductase from the chemoautotroph nitrobacter agilis. | | 1965 | 14284757 |
| determination of kinetic constants for nitrifying bacteria in mixed culture, with the aid of an electronic computer. | | 1965 | 14287204 |
| structure of nitrosocystis oceanus and comparison with nitrosomonas and nitrobacter. | murray, r. g. e. (university of western ontario, london, ont., canada), and s. w. watson. structure of nitrosocystis oceanus and comparison with nitrosomonas and nitrobacter. j. bacteriol. 89:1594-1609. 1965.-nitrosocystis oceanus has distinctive features: the cell wall (overall thickness, 250 a) has an inner triplet structure and a dense enveloping layer; between these lie the "cell-wall organelles" (two or more per cell; plaques about 0.5 mu in diameter and 0.1 mu thick) of unknown function an ... | 1965 | 14293026 |
| [studies on the respiration of nitrobacter winogradskyi buch]. | | 1965 | 14304663 |
| the effect of 2-chloro, 6-(trichloromethyl) pyridine on the chemoautotrophic metabolism of nitrifying bacteria. ii. nitrite oxidation by nitrobacter. | | 1965 | 14315632 |
| [studies on the influence of temperature on nitrification in the elbe estuary]. | | 1964 | 14320216 |
| poly-beta-hydroxybutyric acid in nitrobacter. | | 1965 | 14323606 |
| continuous flow method in soil microbiology. v. nitrification. | | 1965 | 14332135 |
| [comparative studies on the effect of visible light on nitrosomonas europaea and nitrobacter winogradskyi]. | | 1965 | 14347921 |
| the effect of chlorate on the rate of nitrite oxidation by nitrobacter. | | 1954 | 14351163 |
| the use of cyanate and chlorate in studies on the relation between the nitrite oxidation and the reduction of a cytochrome system in nitrobacter. | | 1954 | 14351219 |
| kinetics of the nitrite oxidation by nitrobacter winogradskyi. | | 1960 | 14414502 |
| bacterial destruction of sodium nitrite in open cooling water systems. | | 1959 | 14418926 |
| [the inactivation of the oxidation capacity of nitrobacter winogradskyi buch]. | | 1959 | 14444497 |
| formate odixation by cell-free preparations from nitrobacter agilis. | | 1962 | 14468824 |
| the effect of 2,3,6-trichlorophenylacetic and 2,2-dichloropropionic acids on nitrite oxidation. | the effects of two herbicides, 2,3,6-trichlorophenylacetic acid, sodium salt, and 2,2-dichloropropionic acid, sodium salt, on nitrite-oxidizing bacteria were studied by the soil perfusion technique. the time of application of 2,3,6-trichlorophenylacetic acid affected its toxicity to the nitrifier. when it was present in the environment as the nitrifier started growth, it was more toxic than if the organisms were allowed to nitrify actively before they were subjected to the herbicide. the herbici ... | 1962 | 14471731 |
| growth rates of nitrifying chemoautotrophs in soil. | | 1962 | 14476222 |
| dynamic response of nitrifying activated sludge batch culture to increased chloride concentration. | dynamic response of nitrifying activated sludge batch cultures to increased chloride concentration was studied in this paper, which focused upon the changes in the specific nitrification rate (snr) and nitrifier population when the chloride level was gradually or stepwise increased to 30,000 mg cl l-1. the dominant species of ammonia-oxidizers and nitriteoxidizers in the population were examined by fluorescent in situ hybridization technique with 16s rrna-targeted oligonucleotide probes. it was ... | 2003 | 14509699 |
| molecular analysis of microbial communities in nitrification and denitrification reactors treating high ammonia leachate. | molecular analysis of microbial populations in two bench-scale nitrification and denitrification reactors fed with high ammonia landfill leachate was conducted in this study by using dgge, cloning, and fish techniques in addition to classical efficiency control parameters. nitrification tank was operated with a computer-controlled alkalinity dosing system to supply the alkalinity intermittently as consumed on the basis of on-line ph monitoring. by keeping the ph at 7.0 with this system, 99% nitr ... | 2003 | 14524656 |
| nitrification and nitrifying bacteria in the lower seine river and estuary (france). | the achères wastewater treatment plant, located just downstream of paris, discharges its effluents into the lower seine river. the effluents contain large numbers of heterotrophic bacteria, organic matter, and ammonium and are a source of nitrifying bacteria. as a result, degradation of organic matter by heterotrophic bacteria and subsequent oxygen depletion occur immediately downstream of the effluent outlet, whereas nitrifying bacteria apparently need to build up a significant biomass before a ... | 2003 | 14660353 |
| an analysis of nitrification during the aerobic digestion of secondary sludges. | investigations were undertaken to study the occurrence and progress of nitrification during aerobic digestion of activated sludge in a wide range of initial concentrations of total solids (1000 to 80 000 mg litre(-1), initial ph range of 4.5 to 10.4 and digestion temperature range of 5 degrees to 60 degrees c. batch aerobic digestion studies on activated sludge grown on wastewater (enriched with organic solids from human excretal material) indicate that almost complete elimination of the 'biodeg ... | 1989 | 15092439 |
| nitrite accumulation followed by denitrification using sequencing batch reactor. | biological ammonia-nitrogen removal utilizes two distinct processes, nitrification and denitrification. in nitrification, ammonia oxidizes to nitrite then to nitrate. in this study, elimination of nitrite oxidation to nitrate step was attempted in order to directly remove nitrite to nitrogen gas by denitrification. for this study the supernatant from an anaerobic digester was used as an ammonia source and a sequencing batch reactor (sbr) was employed. emphasis was given to the evaluation of the ... | 2004 | 15137406 |
| effects of seawater salinity on nitrite accumulation in short-range nitrification to nitrite as end product. | the effect of seawater salinity on nitrite accumulation in short-range nitrification to nitrite as the end product was studied by using a sbr. experimental results indicated that the growth of nitrobacteria was inhibited and very high levels of nitrite accumulation at different salinities were achieved under the conditions of 25-28 degrees c, ph 7.5-8.0, and the influent ammonia nitrogen of 40-70 mg/l when seawater flow used to flush toilet was less than 35% (salinity 12393 mg/l, cl- 6778 mg/l) ... | 2004 | 15137648 |
| influence of chemical oxygen demand/total kjeldahl nitrogen ratio and sludge age on nitrification of nitrogenous wastewater. | four laboratory-scale biological nitrification units (influent total kjeldahl nitrogen [tkn] = 1002 to 1062 mg/l) were operated at chemical oxygen demand (cod)/tkn ratios of approximately 0.5, 1.0,15, and 2.0 and at three different sludge ages of 30, 20, and 10 days to study the influence of cod/tkn, sludge age, cod loading, and tkn loading on nitrification and nitrifiers. percent nitrification was found to increase with decreases in cod/tkn and increases in sludge age. the average nitrifier con ... | 2004 | 15168847 |
| dynamics of a pasture soil microbial community after deposition of cattle urine amended with [13c]urea. | within grazed pastures, urine patches are hot spots of nitrogen turnover, since dietary n surpluses are excreted mainly as urea in the urine. this short-term experiment investigated 13c uptake in microbial lipids after simulated deposition of cattle urine at 10.0 and 17.1 g of urea c m(-2). confined field plots without or with cattle urine amendment were sampled after 4 and 14 days, and soil from 0- to 5-cm and 10- to 20-cm depths was analyzed for content and composition of phospholipid fatty ac ... | 2004 | 15528493 |
| treatment of nitrogen and phosphorus in highly concentrated effluent in sbr and sbbr processes. | various sludge treatment processes produced supernatant with high ammonia concentration from 500 to 2,000 mgn/l and generally high phosphate concentration. conversion of ammonia into nitrite via partial nitrification has proven to be an economic way, reducing oxygen and external cod requirements during the nitrification/denitrification process. two processes with biomass retention are studied simultaneously: the sequencing batch reactor (sbr) and the sequencing batch biofilm reactor (sbbr). at a ... | 2004 | 15537016 |
| effect of temperature and free ammonia on nitrification and nitrite accumulation in landfill leachate and analysis of its nitrifying bacterial community by fish. | the cause of seasonal failure of a nitrifying municipal landfill leachate treatment plant utilizing a fixed biofilm was investigated by wastewater analyses and batch respirometric tests at every treatment stage. nitrification of the leachate treatment plant was severely affected by the seasonal temperature variation. high free ammonia (nh3-n) inhibited not only nitrite oxidizing bacteria (nob) but also ammonia oxidizing bacteria (aob). in addition, high ph also increased free ammonia concentrati ... | 2006 | 15927463 |
| para-chlorophenol inhibition on cod, nitrogen and phosphate removal from synthetic wastewater in a sequencing batch reactor. | cod, nitrogen, phosphate and para-chlorophenol (4-chlorophenol, 4-cp) removal from synthetic wastewater was investigated using a four-step sequencing batch reactor (sbr) at different sludge ages and initial para-chlorophenol (4-cp) concentrations. the nutrient removal process consisted of anaerobic, oxic, anoxic and oxic phases with hydraulic residence times (hrt) of 1/3/1/1 h and a settling phase of 0.75 h. a box-wilson statistical experiment design was used considering the sludge age (5-25 day ... | 2005 | 16023572 |
| improvement of nano2-oxidizing activity in nitrobacter vulgaris by coentrapment in polyacrylamide containing polydimethylsiloxane copolymer and deae-sephadex. | removal of nitrite and nitrate from drinking water has attracted great attention in recent years because of the human health risk induced by the exposure to contaminated groundwater and surface water. we have therefore tested a model nitrite oxidation system by coentrapping the nano2 oxidizer nitrobacter vulgaris with polydimethylsiloxane (pdms) copolymer and deae-sephadex in a polyacrylamide gel. the copolymer and the anion exchanger facilitate the diffusion of oxygen and nano2, respectively, i ... | 2005 | 16204501 |
| effects of aeration cycles on nitrifying bacterial populations and nitrogen removal in intermittently aerated reactors. | the effects of the lengths of aeration and nonaeration periods on nitrogen removal and the nitrifying bacterial community structure were assessed in intermittently aerated (ia) reactors treating digested swine wastewater. five ia reactors were operated in parallel with different aeration-to-nonaeration time ratios (ana). populations of ammonia-oxidizing bacteria (aob) and nitrite-oxidizing bacteria (nob) were monitored using 16s rrna slot blot hybridizations. aob species diversity was assessed u ... | 2005 | 16332848 |
| production of no(2) and n(2)o by nitrifying bacteria at reduced concentrations of oxygen. | pure cultures of the marine ammonium-oxidizing bacterium nitrosomonas sp. were grown in the laboratory at oxygen partial pressures between 0.005 and 0.2 atm (0.18 to 7 mg/liter). low oxygen conditions induced a marked decrease in the rate for production of no(2), from 3.6 x 10 to 0.5 x 10 mmol of no(2) per cell per day. in contrast, evolution of n(2)o increased from 1 x 10 to 4.3 x 10 mmol of n per cell per day. the yield of n(2)o relative to no(2) increased from 0.3% to nearly 10% (moles of n i ... | 1980 | 16345632 |
| serological diversity of nitrobacter spp. from soil and aquatic habitats. | serotypic diversity among nitrobacter spp. isolates is greater than previously reported. typing with fluorescent antibodies prepared against 11 nitrobacter spp. cultures isolated from soil and water placed the isolates into six serogroups. when these fluorescent antibodies were applied to a group of 16 additional isolates, 8 were identifiable by cross-reaction to 3 of the 11 fluorescent antibodies. some nitrite-oxidizing enrichment cultures from different habitats contained cross-reacting strain ... | 1981 | 16345749 |
| bicarbonate uptake by nitrifiers: effects of growth rate, ph, substrate concentration, and metabolic inhibitors. | the ratios of bicarbonate uptake to substrate oxidation were measured for three genera of nitrifying bacteria. the ratios for the two ammonium oxidizers tested were essentially the same; 0.0863 +/- 0.0055 and 0.0868 +/- 0.0091 mumol of bicarbonate were taken up per umol ammonium oxidized for nitrosomonas europaea and a nitrosospira strain, respectively. for nitrobacter sp., a ratio of 0.0236 +/- 0.0013 mumol of bicarbonate taken up per umol of nitrite oxidized was obtained. cells were grown in s ... | 1984 | 16346673 |
| nitrifying bacteria in wastewater reservoirs. | deep wastewater reservoirs are used throughout israel to store domestic wastewater effluents for summer irrigation. these effluents contain high concentrations of ammonia (</=5 mm) that are frequently toxic to photosynthetic microorganisms and that lead to development of anoxic conditions. population dynamics of nitrifying bacteria and rates of nitrification were studied in two wastewater reservoirs that differed in organic load and degree of oxygenation and in the laboratory under controlled co ... | 1987 | 16347319 |
| an acidophilic and a neutrophilic nitrobacter strain isolated from the numerically predominant nitrite-oxidizing population of an acid forest soil. | two physiologically and serologically distinct strains of chemoautotrophic nitrite-oxidizing bacteria were isolated as numerically predominant members of the nitrite-oxidizer population of an undisturbed forest soil with a ph range of 4.3 to 5.2. one isolate responded as a neutrophile, characteristic of the family nitrobacteraceae, and cross-reacted strongly with fluorescent antibody to nitrobacter strain engel. the second isolate responded as an acidophile in pure culture, demonstrated maximal ... | 1988 | 16347664 |
| inhibitor evaluation with immobilized nitrobacter agilis cells. | nitrobacter agilis was entrapped in calcium alginate beads and used as a floating bed supplied with a continuous flow of nitrite medium. complete nitrite oxidation was achieved within 30 h, and the system could be maintained for at least 210 h. the immobilized nitrobacter system was subjected to sulfur oxyanions, acidity, and metal ions. thiosulfate and tetrathionate (up to 20 mm each) did not inhibit the nitrite oxidation activity. a low ph of 4.2 resulted in the complete cessation of nitrite o ... | 1986 | 16347230 |