Filamentous bacterial population dominance in activated sludges subject to stresses

2002 ◽  
Vol 46 (1-2) ◽  
pp. 49-53 ◽  
Author(s):  
G. Gaval ◽  
P. Duchène ◽  
J.-J. Pernelle
Keyword(s):  
Wastewater Treatment ◽  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Bacterial Population ◽  
Filamentous Growth ◽  
Volume Index ◽  
Filamentous Bacteria ◽  
Sludge Volume Index ◽  
The One

Evolution of a filamentous bacterial population was monitored on four wastewater treatment pilot plants subject to stresses which have consisted of oxygen deficiencies and/or loading shocks. Fluorescent in situ hybridization (FISH) was used to perform filaments identification and quantification. Results obtained on the different pilot plants have led us to conclude that independently of the nature of the stresses, a single filamentous bacteria species was involved in the increase of the sludge volume index associated to the filamentous growth. In addition, when serial stresses were used, substitutions in dominant filamentous populations occurred: if another filament began to proliferate it caused the regression of the one which dominant.

scholarly journals Chlorine-Susceptible and Chlorine-Resistant Type 021N Bacteria Occurring in Bulking Activated Sludges

2001 ◽  
Vol 67 (11) ◽  
pp. 5303-5307 ◽  
Author(s):  
M. A. Séka ◽  
Y. Kalogo ◽  
F. Hammes ◽  
J. Kielemoes ◽  
W. Verstraete
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Morphological Features ◽  
The Other ◽  
Filamentous Bacteria ◽  
Staining Techniques ◽  
Effect Of Chlorine

ABSTRACT Two filamentous bacteria causing bulking in two activated sludges were examined. Investigations using morphological features, staining techniques, and fluorescent in situ hybridization identified both filaments as type 021N. However, an examination of the effect of chlorine on the sludges revealed a chlorine-susceptible type 021N in one sludge and a chlorine-resistant type 021N in the other.

Novel Nitrospira-like bacteria as dominant nitrite-oxidizers in biofilms from wastewater treatment plants: diversity and in situ physiology

2000 ◽  
Vol 41 (4-5) ◽  
pp. 85-90 ◽  
Author(s):  
H. Daims ◽  
P.H. Nielsen ◽  
J.L. Nielsen ◽  
S. Juretschko ◽  
M. Wagner
Keyword(s):  
Wastewater Treatment ◽  
In Situ Hybridization ◽  
16S Rrna ◽  
Fluorescent In Situ Hybridization ◽  
Wastewater Treatment Plants ◽  
Combined Application ◽  
Fundamental Understanding ◽  
Unculturable Bacteria ◽  
Rrna Sequences

The frequency and distribution of putatively nitrite-oxidizing, Nitrospira- like bacteria in nitrifying biofilms from two reactors receiving wastewater with different ammonia and salt concentrations were observed by fluorescent in situ hybridization. For this purpose, new 16S rRNA-directed oligonucleotide probes targeting the bacterial phylum Nitrospira and the three main lineages within this phylum were developed and evaluated. The diversity of Nitrospira-like bacteria in the reactors was additionally investigated by retrieval and comparative analysis of full 16S rRNA sequences from the biofilms. We found that, despite of the differences in the influent composition, Nitrospira-like bacteria form dominant populations in both reactors. In addition, first insights into the physiology of these still unculturable bacteria were obtained by the incubation of active biofilm samples with radioactively labeled substrates followed by the combined application of fluorescent in situ hybridization and microautoradiography. The results are discussed in consideration of the frequently observed dominance of Nitrospira-like bacteria in nitrifying bioreactors. Consequently, high priority should be assigned to future studies on the ecology and physiology of these organisms in order to increase our fundamental understanding of nitrogen cycling and to enable knowledge-driven future improvements of nitrifying wastewater treatment plants.

Effectiveness of oligonucleotide probes targeted against Thiothrix nivea and type 021N 16S rRNA for in situ identification and population monitoring in activated sludges

1998 ◽  
Vol 37 (4-5) ◽  
pp. 431-440 ◽  
Author(s):  
Jean-Jacques Pernelle ◽  
Eric Cotteux ◽  
Philippe Duchène
Keyword(s):  
In Situ Hybridization ◽  
16S Rrna ◽  
Growth Dynamics ◽  
Population Monitoring ◽  
Morphological Data ◽  
Volume Index ◽  
Available Phosphorus ◽  
Oligonucleotide Probes ◽  
Filamentous Bacteria

In situ hybridization (FISH) of two fluorescent oligonucleotide probes, TNI and 21N, directed against 16S rRNA fragments of Thiothrix nivea and type 021N filamentous bacteria, was used to study activated sludge samples of various origins. Comparison of the results obtained by this technique with morphological data enabled us to evaluate the sensitivity and specificity of the probes, as well as to propose practical classification criteria, in an effort to correlate the identification and ecology of these two microorganisms. We applied the two oligonucleotide probes to the study of Thiothrix sp. in pilot and laboratory batch reactors fed a substrate that was moderately deficient in rapidly available phosphorus. We monitored the growth dynamics of Thiothrix sp. in the pilot reactor, using various hydraulic configurations and after certain perturbations, such as transient substrate overloads. The results provided data which led us to question the importance of the length of time oxygen-deficient sludges spend in clarifier tanks and we discuss the effects of both moderate reductions in oxygen and of very intermittent feedings on the occurrence of Thiothrix sp. growth peaks. The identification and quantification of these filamentous bacteria by size class, made possible by in situ hybridization, are shown to be powerful tools for the early detection and evaluation of episodes of proliferation of filamentous bacteria, revealing them to be much more sensitive indicators than the sludge volume index (SVI).

Study of filamentous bacteria by image analysis and relation with settleability

2002 ◽  
Vol 46 (1-2) ◽  
pp. 363-369 ◽  
Author(s):  
M. da Motta ◽  
M.N. Pons ◽  
N. Roche
Keyword(s):  
Image Analysis ◽  
Wastewater Treatment ◽  
Settling Velocity ◽  
Treatment Plant ◽  
Volume Index ◽  
Morphological Parameters ◽  
Filamentous Bacteria ◽  
Sludge Volume Index ◽  
Floc Size ◽  
Different Temperatures

An automated procedure for the characterisation by image analysis of the morphology of activated sludge has been used to monitor the biomass in a pilot wastewater treatment plant during two runs inoculated with a different sludge and operated at two different temperatures. The bulking events were easily detected by image analysis. Correlations were found between settleability properties (Sludge Volume Index and settling velocity) and the morphological parameters (filament total length, filament number and floc size).

scholarly journals Specific detection of viable Listeria monocytogenes in Spanish wastewater treatment plants by Fluorescent In Situ Hybridization and PCR

2011 ◽  
Vol 45 (15) ◽  
pp. 4634-4640 ◽  
Author(s):  
Yolanda Moreno ◽  
Lorena Ballesteros ◽  
Jorge García-Hernández ◽  
Paula Santiago ◽  
Ana González ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
In Situ Hybridization ◽  
Listeria Monocytogenes ◽  
Fluorescent In Situ Hybridization ◽  
Wastewater Treatment Plants ◽  
Specific Detection

1796: Analysis of Chromosomal Aneuploidy in Patients with Oligoasthenoteratozoospermia(OAT) Using Fluorescent in-situ Hybridization

2007 ◽  
Vol 177 (4S) ◽  
pp. 596-597
Author(s):  
Joseph P. Alukal ◽  
Bobby B. Najari ◽  
Wilson Chuang ◽  
Lata Murthy ◽  
Monica Lopez-Perdomo ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Chromosomal Aneuploidy

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.

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