Publications

comparison of conventional and integrated fixed-film activated sludge systems: attached- and suspended-growth functions and quantitative polymerase chain reaction measurements.	pilot-scale integrated fixed-film activated sludge (ifas) and non-ifas control systems were compared, with respect to overall performance and functional behaviors and microbial population composition in the attached and suspended phases. the suspended phases of the control and ifas systems exhibited similar rates of ammonia consumption; the attached phase in the second aerobic ifas reactor had significantly higher rates of ammonia consumption and nitrate production than any other biomass source, ...	2011	21790081
a specific inorganic triphosphatase from nitrosomonas europaea: structure and catalytic mechanism.	the cyth superfamily of proteins is named after its two founding members, the cyab adenylyl cyclase from aeromonas hydrophila and the human 25-kda thiamine triphosphatase. because these proteins often form a closed +¦-barrel, they are also referred to as "triphosphate tunnel metalloenzymes" (ttm). functionally, they are characterized by their ability to bind triphosphorylated substrates and divalent metal ions. these proteins exist in most organisms and catalyze different reactions, depending on ...	2011	21840996
hessian fly-associated bacteria: transmission, essentiality, and composition.	plant-feeding insects have been recently found to use microbes to manipulate host plant physiology and morphology. gall midges are one of the largest groups of insects that manipulate host plants extensively. hessian fly (hf, mayetiola destructor) is an important pest of wheat and a model system for studying gall midges. to examine the role of bacteria in parasitism, a systematic analysis of bacteria associated with hf was performed for the first time. diverse bacteria were found in different de ...	2011	21858016
removal of persistent pharmaceutical micropollutants from sewage by addition of pac in a sequential membrane bioreactor.	the performance of a membrane bioreactor operating in a sequential mode (smbr) using an external flat-plate membrane was investigated. after 200 days of operation, a single addition of 1 g l(-1) powdered activated carbon (pac) was added directly into the mixed liquor in order to enhance the simultaneous removal of nutrients and pharmaceutical micropollutants from synthetic urban wastewater. throughout the entire operation (288 days), chemical oxygen demand (cod) removal efficiencies were up to 9 ...	2011	21864878
genome sequence of nitrosomonas sp. strain al212, an ammonia-oxidizing bacterium sensitive to high levels of ammonia.	nitrosomonas sp. strain al212 is an obligate chemolithotrophic ammonia-oxidizing bacterium (aob) that was originally isolated in 1997 by yuichi suwa and colleagues. this organism belongs to nitrosomonas cluster 6a, which is characterized by sensitivity to high ammonia concentrations, higher substrate affinity (lower k(m)), and lower maximum growth rates than strains in nitrosomonas cluster 7, which includes nitrosomonas europaea and nitrosomonas eutropha. genome-informed studies of this ammonia- ...	2011	21868805
active autotrophic ammonia-oxidizing bacteria in biofilm enrichments from simulated creek ecosystems at two ammonium concentrations respond to temperature manipulation.	the first step of nitrification, the oxidation of ammonia to nitrite, is important for reducing eutrophication in freshwater environments when coupled with anammox (anaerobic ammonium oxidation) or denitrification. we analyzed active formerly biofilm-associated aerobic ammonia-oxidizing communities originating from ammerbach (as) and leutra south (ls) stream water (683 ± 550 [mean ± standard deviation] and 16 ± 7 μm nh(4)(+), respectively) that were developed in a flow-channel experiment and inc ...	2011	21890674
Improving nitrogen removal in two modified decentralized wastewater systems.	Efficient nutrient removal in decentralized wastewater treatment systems is a challenging task. To improve the removal of organic matter and nitrogen from wastewater, two types of bioreactors using membrane-aerated biofilm reactor (MABR) and microbial fuel cell (MFC) techniques were evaluated. During more than 250 days of continuous-flow reactor operation, both reactors showed consistently high chemical oxygen demand removal (>86%). At an influent ammonium-nitrogen (NH4(+)-N) concentration of 30 ...	2011	21905409
Influence of operational parameters on nitrogen removal efficiency and microbial communities in a full-scale activated sludge process.	To improve the efficiency of total nitrogen (TN) removal, solid retention time (SRT) and internal recycling ratio controls were selected as operating parameters in a full-scale activated sludge process treating high strength industrial wastewater. Increased biomass concentration via SRT control enhanced TN removal. Also, decreasing the internal recycling ratio restored the nitrification process, which had been inhibited by phenol shock loading. Therefore, physiological alteration of the bacteria ...	2011	21924454
effect of elevated salt concentrations on the aerobic granular sludge process: linking microbial activity with microbial community structure.	the long- and short-term effects of salt on biological nitrogen and phosphorus removal processes were studied in an aerobic granular sludge reactor. the microbial community structure was investigated by pcr-denaturing gradient gel electrophoresis (dgge) on 16s rrna and amoa genes. pcr products obtained from genomic dna and from rrna after reverse transcription were compared to determine the presence of bacteria as well as the metabolically active fraction of bacteria. fluorescence in situ hybrid ...	2011	21926194
low-dissolved-oxygen nitrifying systems exploit ammonia-oxidizing bacteria with unusually high yields.	in wastewater treatment plants, nitrifying systems are usually operated with elevated levels of aeration to avoid nitrification failures. this approach contributes significantly to operational costs and the carbon footprint of nitrifying wastewater treatment processes. in this study, we tested the effect of aeration rate on nitrification by correlating ammonia oxidation rates with the structure of the ammonia-oxidizing bacterial (aob) community and aob abundance in four parallel continuous-flow ...	2011	21926211
dynamic and distribution of ammonia-oxidizing bacteria communities during sludge granulation in an anaerobic-aerobic sequencing batch reactor.	the structure dynamic of ammonia-oxidizing bacteria (aob) community and the distribution of aob and nitrite-oxidizing bacteria (nob) in granular sludge from an anaerobic-aerobic sequencing batch reactor (sbr) were investigated. a combination of process studies, molecular biotechniques and microscale techniques were employed to identify and characterize these organisms. the aob community structure in granules was substantially different from that of the initial pattern of the inoculants sludge. a ...	2011	21955984
characterization of the microbial community in a partial nitrifying sequencing batch biofilm reactor.	a lab-scale partial nitrifying sequencing batch biofilm reactor was a successful start-up. denaturing gradient gel electrophoresis (dgge) was used to investigate the bacterial community dynamics in three periods together with inocula sludge at ambient temperature. the dgge profiles of bacteria and shannon-wiener index (h') results showed that high free ammonia (fa) concentration referred to lower diversity in the bioreactor system. cluster analysis indicated that microorganism in period iii was ...	2011	21956665
community shift of ammonia-oxidizing bacteria along an anthropogenic pollution gradient from the pearl river delta to the south china sea.	the phylogenetic diversity and abundance of ammonia-oxidizing beta-proteobacteria (beta-aob) was analyzed along an anthropogenic pollution gradient from the coastal pearl river delta to the south china sea using the ammonia monooxygenase subunit a (amoa) gene. along the gradient from coastal to the open ocean, the phylogenetic diversity of the dominant genus changed from nitrosomonas to nitrosospira, indicating the niche specificity by these two genera as both salinity and anthropogenic influenc ...	2011	22005744
growth of ammonia-oxidizing archaea and bacteria in cattle manure compost under various temperatures and ammonia concentrations.	a recent study showed that ammonia-oxidizing bacteria (aob) and ammonia-oxidizing archaea (aoa) coexist in the process of cattle manure composting. to investigate their physiological characteristics, liquid cultures seeded with fermenting cattle manure compost were incubated at various temperatures (37°c, 46°c, or 60°c) and ammonium concentrations (0.5, 1, 4, or 10 mm nh (4) (+) -n). the growth rates of the aob and ao ...	2011	22072124
Abundance and composition of epiphytic bacterial and archaeal ammonia oxidizers of marine red and brown macroalgae.	Ammonia-oxidizing bacteria (AOB) and archaea (AOA) are important for nitrogen cycling in marine ecosystems. Little is known about the diversity and abundance of these organisms on the surface of marine macroalgae, despite the algae's potential importance to create surfaces and local oxygen-rich environments supporting ammonia oxidation at depths with low dissolved oxygen levels. We determined the abundance and composition of the epiphytic bacterial and archaeal ammonia-oxidizing communities on t ...	2012	22081571
differential photoinhibition of bacterial and archaeal ammonia oxidation.	inhibition by light potentially influences the distribution of ammonia oxidizers in aquatic environments and is one explanation for nitrite maxima near the base of the euphotic zone of oceanic waters. previous studies of photoinhibition have been restricted to bacterial ammonia oxidizers, rather than archaeal ammonia oxidizers, which dominate in marine environments. to compare the photoinhibition of bacterial and archaeal ammonia oxidizers, specific growth rates of two ammonia-oxidizing archaea ...	2011	22093004
nitrogen removal and ammonia-oxidising bacteria in a vertical flow constructed wetland treating inorganic wastewater.	nitrogen removal performance and the ammonia-oxidising bacterial (aob) community were assessed in the batch loaded 1.3 ha saturated surface vertical flow wetland at csbp ltd, a fertiliser and chemical manufacturer located in kwinana, western australia. from september 2008 to october 2009 water quality was monitored and sediment samples collected for bacterial analyses. during the period of study the wetland received an average inflow of 1,109 m3/day with nh3-n = 40 mg/l and no3-n = 23 mg/l. effl ...	2011	22097035
identifying sources of nitrous oxide emission in anoxic/aerobic sequencing batch reactors (a/o sbrs) acclimated in different aeration rates.	both long term and batch experiments were carried out to identify the sources of the n(2)o emission in anoxic/aerobic sequencing batch reactors (a/o sbrs) under different aeration rates. the obtained results showed that aeration rate has an important effect on the n(2)o emission of a/o sbr and most of the n(2)o was emitted during the aerobic phase. during the anoxic phase, nitrate ammonification was the major source of n(2)o emission while denitrification performed as a sink of n(2)o, in all thr ...	2011	22112415
Biofilm formation and microbial community analysis of the simulated river bioreactor for contaminated source water remediation.	BACKGROUND, AIM, AND SCOPE: The start-up pattern of biofilm remediation system affects the biofilm characteristics and operating performances. The objective of this study was to evaluate the performances of the contaminated source water remediation systems with different start-up patterns in view of the pollutants removal performances and microbial community succession. METHODS: The operating performances of four ...	2011	22120124
Adaptation of ammonia-oxidizing microbes to environment shift of paddy field soil.	Adaptation of microbes to the environment is a central theme in microbial ecology. The objective of the present study was to investigate the response of ammonia-oxidizing bacteria (AOB) and archaea (AOA) to a soil medium shift. We employed two rice field soils collected from Beijing and Hangzhou, China respectively. These soils contained distinct AOB communities dominated by Nitrosomonas in Beijing rice soil and Nitrosospira in Hangzhou rice soil. Three mixtures were generated by mixing equal qu ...	2011	22145990
Influence of growth manner on nitrifying bacterial communities and nitrification kinetics in three lab-scale bioreactors.	The effects of growth type, including attached growth, suspended growth, and combined growth, on the characteristics of communities of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were studied in three lab-scale Anaerobic/Anoxic(m)-Oxic(n) (AmOn) systems. These systems amplified activated sludge, biofilms, and a mixture of activated sludge and biofilm (AS-BF). Identical inocula were adopted to analyze the selective effects of mixed growth patterns on nitrifying bacteria. ...	2011	22160273
Global analysis of the Nitrosomonas europaea iron starvation stimulon.	The importance of iron to the metabolism of the ammonia-oxidizing bacterium Nitrosomonas europaea is well known. However, the mechanisms by which N. europaea acquires iron under iron limitation are less well known. To obtain insight into these mechanisms, transcriptional profiling of N. europaea was performed during growth under different iron availabilities. Of 2,355 N. europaea genes on DNA microarrays, transcripts for 247 genes were identified as differentially expressed when cells were grown ...	2011	22173827