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 ◽  
...  

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.

2003 ◽  
Vol 47 (1) ◽  
pp. 97-104 ◽  
Author(s):  
D.W. Han ◽  
J.S. Chang ◽  
D.J. Kim

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.


2000 ◽  
Vol 90 (3) ◽  
pp. 234-240 ◽  
Author(s):  
YOSHITERU AOI ◽  
TOMOKO MIYOSHI ◽  
TOSHIYUKI OKAMOTO ◽  
SATOSHI TSUNEDA ◽  
AKIRA HIRATA ◽  
...  

2005 ◽  
Vol 52 (7) ◽  
pp. 135-141 ◽  
Author(s):  
R. Nogueira ◽  
D. Elenter ◽  
A. Brito ◽  
L.F. Melo ◽  
M. Wagner ◽  
...  

The objective of this study was to evaluate the significance of heterotrophic growth in nitrifying biofilm reactors fed only with ammonium as an energy source. The diversity, abundance and spatial distribution of nitrifying bacteria were studied using a combination of molecular tools and mathematical modeling, in two biofilm reactors operated with different hydraulic retention times. The composition and distribution of nitrifying consortia in biofilms were quantified by fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes combined with confocal laser scanning microscopy (CLSM) and digital image analysis. Autotrophic and heterotrophic biofilm fractions determined by FISH were compared to the output from a multispecies model that incorporates soluble microbial products (SMP) production/consumption. In reactor R1 (short retention time) nearly 100% of the total bacteria could be identified as either ammonia- or nitrite-oxidizing bacteria by quantitative FISH analyses, while in reactor R2 (long retention time) the identification rate was only 73%, with the rest probably consisting of heterotrophs. Mathematical simulations were performed to evaluate the influence of the hydraulic retention time (HRT), biofilm thickness, and substrate utilization associated SMP production on the growth of heterotrophic bacteria. The model predicts that low HRTs resulted in a lower availability of SMPs leading to purely autotrophic biofilms. These model predictions are consistent with experimental observations. At HRTs that are about an order of magnitude larger than the reciprocal of the net maximum growth rate the majority of the active biomass will grow suspended in the bulk phase rather than in the biofilm.


2018 ◽  
Vol 38 (6) ◽  
pp. 619-622
Author(s):  
Michael Liew ◽  
Leslie R. Rowe ◽  
Phillipe Szankasi ◽  
Christian N. Paxton ◽  
Todd Kelley ◽  
...  

Genes ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 375 ◽  
Author(s):  
Xiaomei Luo ◽  
Juncheng Liu

We report the cytogenetic map for a collection of species in the Oleaceae, and test similarities among the karyotypes relative to their known species phylogeny. The oligonucleotides 5S ribosomal DNA (rDNA), (AGGGTTT)3, and (TTG)6 were used as fluorescence in situ hybridization (FISH) probes to locate the corresponding chromosomes in three Oleaceae genera: Fraxinus pennsylvanica, Syringa oblata, Ligustrum lucidum, and Ligustrum × vicaryi. Forty-six small chromosomes were identified in four species. (AGGGTTT)3 signals were observed on almost all chromosome ends of four species, but (AGGGTTT)3 played no role in distinguishing the chromosomes but displayed intact chromosomes and could thus be used as a guide for finding chromosome counts. (TTG)6 and 5S rDNA signals discerned several chromosomes located at subterminal or central regions. Based on the similarity of the signal pattern (mainly in number and location and less in intensity) of the four species, the variations in the 5S rDNA and (TTG)6 distribution can be ordered as L. lucidum < L. × vicaryi < F. pennsylvanica < S. oblata. Variations have observed in the three genera. The molecular cytogenetic data presented here might serve as a starting point for further larger-scale elucidation of the structure of the Oleaceae genome, and comparison with the known phylogeny of Oleaceae family.


2018 ◽  
Vol 142 (10) ◽  
pp. 1254-1259 ◽  
Author(s):  
Katherine B. Geiersbach ◽  
Julia A. Bridge ◽  
Michelle Dolan ◽  
Lawrence J. Jennings ◽  
Diane L. Persons ◽  
...  

Context.— Fluorescence in situ hybridization (FISH) and brightfield in situ hybridization (ISH) are 2 clinically approved laboratory methods for detecting ERBB2 (HER2) amplification in breast cancer. Objective.— To compare the performance of FISH and brightfield ISH on proficiency testing administered by the College of American Pathologists Laboratory Accreditation Program. Design.— Retrospective review was performed on 70 tissue core samples in 7 separate proficiency testing surveys conducted between 2009 and 2013. Results.— The samples included 13 consensus-amplified tissue cores, 53 consensus-nonamplified cores, and 4 cores that did not reach consensus for FISH and/or brightfield ISH. There were 2552 individual responses for FISH and 1871 individual responses for brightfield ISH. Consensus response rates were comparable for FISH (2474 of 2524; 98.0%) and brightfield ISH (2135 of 2189; 97.5%). The FISH analysis yielded an average HER2 copy number per cell that was significantly higher (by 2.86; P = .02) compared with brightfield ISH for amplified cores. For nonamplified cores, FISH yielded slightly, but not significantly, higher (by 0.17; P = .10) HER2 copy numbers per cell. There was no significant difference in the average HER2 to control ratio for either consensus-amplified or consensus-nonamplified cores. Participants reported “unable to analyze” more frequently for brightfield ISH (244 of 2453; 9.9%) than they did for FISH (160 of 2684; 6.0%). Conclusions.— Our study indicates a high concordance rate in proficiency testing surveys, with some significant differences noted in the technical performance of these assays. In borderline cases, updated American Society of Clinical Oncology/College of American Pathologists cutoff thresholds that place greater emphasis on HER2 copy number per cell could accentuate those differences between FISH and brightfield ISH.


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