Formation mechanism of nitrifying granules observed in an aerobic upflow fluidized bed (AUFB) reactor

2004 ◽  
Vol 49 (11-12) ◽  
pp. 27-34 ◽  
Author(s):  
S. Tsuneda ◽  
Y. Ejiri ◽  
T. Nagano ◽  
A. Hirata
Keyword(s):  
Shear Stress ◽  
Fluidized Bed ◽  
Formation Mechanism ◽  
Nitrifying Bacteria ◽  
Second Step ◽  
Fish Analysis ◽  
Seed Sludge ◽  
Rapid Production ◽  
Granulation Mechanism

The influences of trace metals in the wastewater and shear stress by aeration were particularly examined to clarify the formation mechanism of nitrifying granules in an aerobic upflow fluidized bed (AUFB) reactor. It was found that Fe added as a trace element to the inorganic wastewater accumulated at the central part of the nitrifying granules. Another result obtained was that suitable shear stress by moderate aeration (0.07-0.20 L/min/L-bed) promoted granulation. Furthermore, it was successfully demonstrated that pre-aggregation of seed sludge using hematite promoted core formation, leading to rapid production of nitrifying granules. From these results, a nitrifying granulation mechanism is proposed: 1) as a first step, nitrifying bacteria aggregate along with Fe precipitation, and then the cores of granules are formed; 2) as a second step, the aggregates grow to be spherical or elliptical in form due to multiplication of the nitrifying bacteria and moderate shear stress in the reactor, and then mature nitrifying granules are produced. Fluorescence in situ hybridization (FISH) analysis successfully visualized the change in the spatial distribution of nitrifying bacteria in the granules, which supports the proposed granulation mechanism.

Biological Treatment of High Ammonium Content Urban Landfill Leachate Using an Anaerobic-Aerobic Process

2013 ◽  
Vol 781-784 ◽  
pp. 2095-2099
Author(s):  
Hong Wei Sun ◽  
Yong Jun You ◽  
Ying Guo
Keyword(s):  
Landfill Leachate ◽  
Inhibitory Effect ◽  
Nitrifying Bacteria ◽  
Anaerobic Sludge ◽  
Nitrite Accumulation ◽  
Fish Analysis ◽  
Free Nitrous Acid ◽  
Nitrite Oxidizing Bacteria ◽  
Anaerobic Sludge Blanket

Biological system consisting of an up-flow anaerobic sludge blanket (UASB) and anoxic-oxic (A/O) reactor was applied to treat high ammonium content urban landfill leachate. Inhibitory effect of free ammonia (FA) and free nitrous acid (FNA) on nitrifying bacteria activity was used to achieve nitrogen removal via nitrite pathway in the A/O. Results demonstrated that removed efficiencies of COD, total nitrogen (TN) and NH4+-N were 95.3%, 84.6 %and 99.2%, respectively. Stable nitrite pathway with above 90% nitrite accumulation was successfully achieved in the A/O reactor by synergetic inhibition of FA and FNA on the activity of nitrite oxidizing bacteria (NOB). Moreover, Fluorescence in situ hybridization (FISH) analysis showed that AOB was dominant microorganism.

Tailoring of highly efficient nitrifying biofilms in fluidized bed for ammonia-rich industrial wastewater treatment

2000 ◽  
Vol 42 (3-4) ◽  
pp. 357-362 ◽  
Author(s):  
S. Tsuneda ◽  
T. Miyoshi ◽  
Y. Aoi ◽  
A. Hirata
Keyword(s):  
Fluidized Bed ◽  
Industrial Wastewater ◽  
Domestic Wastewater ◽  
Nitrifying Bacteria ◽  
Nitrification Rate ◽  
Fish Analysis ◽  
Ammonia Oxidizing Bacteria ◽  
High Concentration ◽  
Stepwise Reduction ◽  
Biofilm Structure

We proposed two tailoring methods for efficient nitrifying biofilms on particles which are expected to be used in fluidized bed in nitrogen removal processes for industrial wastewaters. The first method was examined with gradual reduction of the hydraulic retention time in continuous feeding reactor to form biofilm with high nitrification ability. As a result, nitrification rate was successfully improved mainly due to acclimation of nitrifying bacteria to higher loading. The second tailoring method for nitrifying biofilm started with the biofilm which had been previously constructed in synthetic domestic wastewater containing high concentration of NH4+-N as well as various biodegradable organic compounds. Stepwise reduction of C/N ratio in inlet wastewater was performed during one month simultaneously with observation of microbial population dynamics in the biofilm using fluorescent in situ hybridization (FISH) analysis. As a result, this acclimation process promoted occupation of the biofilm by ammonia-oxidizing bacteria and resulted in making suitable biofilm structure for nitrification of ammonia-rich industrial wastewater. Moreover, it is confirmed that this new tailoring method greatly shortened required time to obtain nitrifying biofilms.

Fluorescence in situ hybridization analysis of nitrifiers in piggery wastewater treatment reactors

2004 ◽  
Vol 49 (5-6) ◽  
pp. 333-340 ◽  
Author(s):  
D.J. Kim ◽  
T.K. Kim ◽  
E.J. Choi ◽  
W.C. Park ◽  
T.H. Kim ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Ammonia Concentration ◽  
Biofilm Reactor ◽  
Nitrifying Bacteria ◽  
Fish Analysis ◽  
Ammonia Oxidizing Bacteria ◽  
Piggery Wastewater

Fluorescence in situ hybridization (FISH) was performed to analyze the nitrifying microbial communities in an activated sludge reactor (ASR) and a fixed biofilm reactor (FBR) for piggery wastewater treatment. Heterotrophic oxidation and nitrification were occurring simultaneously in the ASR and the COD and nitrification efficiencies depend on the loads. In the FBR nitrification efficiency also depends on ammonium load to the reactor and nitrite was accumulated when free ammonia concentration was higher than 0.2 mg NH3-N/L. FISH analysis showed that ammonia-oxidizing bacteria (NSO1225) and denitrifying bacteria (RRP1088) were less abundant than other bacteria (EUB338) in ASR. Further analysis on nitrifying bacteria in the FBR showed that Nitrosomonas species (NSM156) and Nitrospira species (NSR1156) were the dominant ammonia-oxidizing and nitrite-oxidizing bacteria, respectively, in the piggery wastewater nitrification system.

Nitrifying microbial community analysis of nitrite accumulating biofilm reactor by fluorescence in situ hybridization

2003 ◽  
Vol 47 (1) ◽  
pp. 97-104 ◽  
Author(s):  
D.W. Han ◽  
J.S. Chang ◽  
D.J. Kim
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Selective Inhibition ◽  
Biofilm Reactor ◽  
Microbial Community Analysis ◽  
Nitrifying Bacteria ◽  
Nitrite Accumulation ◽  
Fish Analysis ◽  
Oxidation Activity

Biological nitrogen removal via nitrite pathway in wastewater treatment is very important especially in the cost of aeration and as an electron donor for denitrification. Wastewater nitrification and nitrite accumulations were carried out in a biofilm reactor. The biofilm reactor showed almost complete nitrification and most of the oxidized ammonium was present as nitrite at the ammonium load of 1.2 kg N/m3/d. Nitrite accumulation was achieved by the selective inhibition of nitrite oxidizers by free ammonia and oxygen limitation. Nitrite oxidation activity was recovered as soon as the inhibition factor was removed. Fluorescence in situ hybridization studies of the nitrite accumulating biofilm system have shown that genus Nitrosomonas which is specifically hybridized with probe NSM156 was the dominant nitrifying bacteria while Nitrospira was less abundant than those of normal nitrification systems. Further FISH analysis showed that the combinations of Nitrosomonas and Nitrospira cells were identified as important populations of nitrifying bacteria in an autotrophic nitrifying biofilm system.

scholarly journals Identification and Activities In Situ of Nitrosospiraand Nitrospira spp. as Dominant Populations in a Nitrifying Fluidized Bed Reactor

1998 ◽  
Vol 64 (9) ◽  
pp. 3480-3485 ◽  
Author(s):  
Andreas Schramm ◽  
Dirk de Beer ◽  
Michael Wagner ◽  
Rudolf Amann
Keyword(s):  
Fluidized Bed ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Fluidized Bed Reactor ◽  
Molecular Techniques ◽  
Fish Analysis ◽  
Nitrite Oxidizing Bacteria ◽  
Gradient Gel Electrophoresis ◽  
Bacterial Aggregates ◽  
In Situ Detection

ABSTRACT 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 μm of the aggregates. The ammonia oxidizers were identified as members of theNitrosospira group by fluorescence in situ hybridization (FISH). No ammonia- or nitrite-oxidizing bacteria of the genus Nitrosomonas or Nitrobacter, respectively, could be detected by FISH. To identify the nitrite oxidizers, a 16S ribosomal DNA clone library was constructed and screened by denaturing gradient gel electrophoresis and selected clones were sequenced. The organisms represented by these sequences formed two phylogenetically distinct clusters affiliated with the nitrite oxidizerNitrospira moscoviensis. 16S rRNA-targeted oligonucleotide probes were designed for in situ detection of these organisms. FISH analysis showed that the dominant populations of Nitrospiraspp. and Nitrosospira spp. formed separate, dense clusters which were in contact with each other and occurred throughout the aggregate. A second, smaller, morphologically and genetically different population of Nitrospira spp. was restricted to the outer nitrifying zones.

Rapid quantification and in situ detection of nitrifying bacteria in biofilms by monoclonal antibody method

2000 ◽  
Vol 41 (4-5) ◽  
pp. 301-308 ◽  
Author(s):  
N. Noda ◽  
H. Ikuta ◽  
Y. Ebie ◽  
A. Hirata ◽  
S. Tsuneda ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Fluorescent Antibody ◽  
Nitrifying Bacteria ◽  
Fluorescent Antibody Technique ◽  
Antibody Technique ◽  
Antibody Method ◽  
In Situ Detection ◽  
Rapid Quantification

Fluorescent antibody technique by the monoclonal antibody method is very useful and helpful for the rapid quantification and in situ detection of the specific bacteria like nitrifiers in a mixed baxterial habitat such as a biofilm. In this study, twelve monoclonal antibodies against Nitrosomonas europaea (IFO14298) and sixteen against Nitrobacter winogradskyi (IFO14297) were raised from splenocytes of mice (BALB/c). It was found that these antibodies exhibited little cross reactivity against various kinds of heterotrophic bacteria. The direct cell count method using monoclonal antibodies could exactly detect and rapidly quantify N. europaea and N. winogradskyi. Moreover, the distribution of N. europaea and N. winogradskyi in a biofilm could be examined by in situ fluorescent antibody technique. It was shown that most of N. winogradskyi existed near the surface part and most of N. europaea existed at the inner part of the polyethylene glycol (PEG) gel pellet, which had entrapped activated sludge and used in a landfill leachate treatment reactor. It was suggested that this monoclonal antibody method was utilized for estimating and controlling the population of nitrifying bacteria as a quick and favorable tool.

scholarly journals Jacobsen syndrome and neonatal bleeding: report on two unrelated patients

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Gregorio Serra ◽  
Luigi Memo ◽  
Vincenzo Antona ◽  
Giovanni Corsello ◽  
Valentina Favero ◽  
...  
Keyword(s):  
Developmental Delay ◽  
De Novo ◽  
Comparative Genomic ◽  
Fish Analysis ◽  
Variable Degree ◽  
Jacobsen Syndrome ◽  
Contiguous Gene ◽  
Clinical Consequences ◽  
11Q Deletion

Abstract Introduction In 1973, Petrea Jacobsen described the first patient showing dysmorphic features, developmental delay and congenital heart disease (atrial and ventricular septal defect) associated to a 11q deletion, inherited from the father. Since then, more than 200 patients have been reported, and the chromosomal critical region responsible for this contiguous gene disorder has been identified. Patients’ presentation We report on two unrelated newborns observed in Italy affected by Jacobsen syndrome (JBS, also known as 11q23 deletion). Both patients presented prenatal and postnatal bleeding, growth and developmental delay, craniofacial dysmorphisms, multiple congenital anomalies, and pancytopenia of variable degree. Array comparative genomic hybridization (aCGH) identified a terminal deletion at 11q24.1-q25 of 12.5 Mb and 11 Mb, in Patient 1 and 2, respectively. Fluorescent in situ hybridization (FISH) analysis of the parents documented a de novo origin of the deletion for Patient 1; parents of Patient 2 refused further genetic investigations. Conclusions Present newborns show the full phenotype of JBS including thrombocytopenia, according to their wide 11q deletion size. Bleeding was particularly severe in one of them, leading to a cerebral hemorrhage. Our report highlights the relevance of early diagnosis, genetic counselling and careful management and follow-up of JBS patients, which may avoid severe clinical consequences and lower the mortality risk. It may provide further insights and a better characterization of JBS, suggesting new elements of the genotype-phenotype correlations.

Fluorescent in situ hybridization (FISH): A useful diagnostic tool for childhood conjunctival melanoma

2021 ◽  
pp. 112067212110307
Author(s):  
Raquel María Moral ◽  
Carlos Monteagudo ◽  
Javier Muriel ◽  
Lucía Moreno ◽  
Ana María Peiró
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Pediatric Population ◽  
Diagnostic Technique ◽  
Histopathological Diagnosis ◽  
Fish Analysis ◽  
Conjunctival Melanoma ◽  
Adequate Treatment ◽  
First Case

Introduction: Conjunctival melanoma is extremely rare in children and has low rates of resolution. Definitive histopathological diagnosis based exclusively on microscopic findings is sometimes difficult. Thus, early diagnosis and adequate treatment are essential to improve clinical outcomes. Clinical case: We present the first case in which the fluorescent in situ hybridization (FISH) diagnostic technique was applied to a 10-year-old boy initially suspected of having amelanotic nevi in his right eye. Based on the 65% of tumor cells with 11q13 (CCND1) copy number gain and 33% with 6p25 (RREB1) gain as measured by the FISH analysis, and on supporting histopathological findings, the diagnosis of conjunctival melanoma could be made. Following a larger re-excision, adjuvant therapy with Mitomycin C (MMC), cryotherapy and an amniotic membrane graft, the patient has remained disease-free during 9 years of long-term follow-up. Case discussion: Every ophthalmologist should remember to consider and not forget the possibility of using FISH analyses during the differential diagnosis of any suspicious conjunctival lesions. Genetic techniques, such as FISH, have led to great advances in the classification of ambiguous lesions. Evidence-based guidelines for diagnosing conjunctival melanoma in the pediatric population are needed to determine the most appropriate strategy for this age group.

scholarly journals In situ total scattering experiments of nucleation and crystallisation of tantalum-based oxides: from highly dilute solutions via cluster formation to nanoparticles

Nanoscale ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 150-162
Author(s):  
Ezgi Onur Şahin ◽  
Harun Tüysüz ◽  
Candace K. Chan ◽  
Gun-hee Moon ◽  
Yitao Dai ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Cluster Formation ◽  
Dilute Solutions ◽  
Total Scattering ◽  
Alkoxide Precursors

The formation mechanism of amorphous tantalum oxides was studied by total scattering experiments starting from alkoxide precursors. Hydrolysed TaxOyHz clusters form in highly dilute solutions which were transformed into L-Ta2O5 by calcination.

Laboratory Testing for HER2/neu in Breast Carcinoma: An Evolving Strategy to Predict Response to Targeted Therapy

2001 ◽  
Vol 8 (5) ◽  
pp. 415-418 ◽  
Author(s):  
Nils M. Diaz
Keyword(s):  
Targeted Therapy ◽  
Breast Carcinoma ◽  
Gene Amplification ◽  
Laboratory Testing ◽  
False Positives ◽  
Response To Therapy ◽  
Fish Analysis ◽  
Breast Carcinomas ◽  
Testing Strategies

Background Laboratory testing of HER2/neu in breast carcinoma has become vital to patient care following the approval of trastuzumab as the first therapy to target the HER2/neu oncoprotein. Initial clinical trials used immunohistochemistry (IHC) to test for HER2/neu overexpression in order to select patients for therapy. Fluorescence in situ hybridization (FISH), which tests for gene amplification, is more specific and sensitive than IHC when either assay is compared with HER2/neu overexpression as determined by Northern or Western blot analysis. Many weak overexpressors on IHC testing are not gene amplified on FISH analysis. Such weak overexpressors may be considered false-positives and raise the question of how best to test for HER2/neu. Methods The literature was surveyed regarding testing for HER2/neu overexpression in breast carcinomas and alternative testing strategies. Results False-positive results are a significant problem when IHC is exclusively used to test for HER2/neu overexpression. The false-positives are overwhelmingly confined to the group of 2+ positives and do not respond to targeted therapy. In contrast, concordance between IHC and FISH is high when immunostaining is interpreted as either negative or strongly positive (3+). Whereas some recent studies have suggested that FISH may better predict response to anti-HER2/neu therapy than IHC, others have indicated that IHC is as effective a predictor as FISH. IHC is less technically demanding and costly than FISH. Conclusions IHC analysis of HER2/neu in breast carcinoma is a useful predictor of response to therapy with trastuzumab when strongly positive. Negative immunostaining is highly concordant with a lack of gene amplification by FISH. Most weakly positive overexpressors are false-positives on testing with FISH. Thus, screening of breast carcinomas with IHC and confirmation of weakly positive IHC results by FISH is an effective evolving strategy for testing HER2/neu as a predictor of response to targeted therapy.

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