Microbial quantification in activated sludge: the hits and misses

2003 ◽  
Vol 48 (3) ◽  
pp. 121-126 ◽  
Author(s):  
S.J. Hall ◽  
J. Keller ◽  
L.L. Blackall
Keyword(s):  
Activated Sludge ◽  
Molecular Genetic ◽  
In Situ Hybridisation ◽  
Biological Nutrient Removal ◽  
Physical Parameters ◽  
Fluorescence In Situ Hybridisation ◽  
Batch Tests ◽  
Polymerase Chain ◽  
Key Microorganisms

Since the implementation of the activated sludge process for treating wastewater, there has been a reliance on chemical and physical parameters to monitor the system. However, in biological nutrient removal (BNR) processes, the microorganisms responsible for some of the transformations should be used to monitor the processes with the overall goal to achieve better treatment performance. The development of in situ identification and rapid quantification techniques for key microorganisms involved in BNR are required to achieve this goal. This study explored the quantification of Nitrospira, a key organism in the oxidation of nitrite to nitrate in BNR. Two molecular genetic microbial quantification techniques were evaluated: real-time polymerase chain reaction (PCR) and fluorescence in situ hybridisation (FISH) followed by digital image analysis. A correlation between the Nitrospira quantitative data and the nitrate production rate, determined in batch tests, was attempted. The disadvantages and advantages of both methods will be discussed.

Assessing the abundance and activity of denitrifying polyphosphate accumulating organisms through molecular and chemical techniques

2010 ◽  
Vol 61 (8) ◽  
pp. 2061-2068 ◽  
Author(s):  
Adrian Oehmen ◽  
Gilda Carvalho ◽  
Filomena Freitas ◽  
Maria AM Reis
Keyword(s):  
In Situ Hybridisation ◽  
Analytical Techniques ◽  
Biological Nutrient Removal ◽  
Future Research ◽  
Fluorescence In Situ Hybridisation ◽  
Batch Tests ◽  
Oxygen Requirements ◽  
Polyphosphate Accumulating Organisms ◽  
Quantitative Fluorescence

Biological nutrient removal (BNR) plants can reduce both carbon and oxygen requirements by increasing the fraction of phosphorus (P) removed by denitrifying polyphosphate accumulating organisms (DPAOs). Contrasting findings have been reported in literature concerning whether or not PAOs and DPAOs are different microorganisms. In this study, quantitative fluorescence in situ hybridisation (FISH) measurements from different EBPR sludges support the hypothesis that PAOs and DPAOs are phyogenetically different. This experimental evidence is discussed within the context of literature findings and suggestions for future research concerning the identity of PAOs and DPAOs are proposed. Further, this paper discusses the different methodologies available for assessing the DPAO fraction through chemical analytical techniques, where the relative fraction estimated is highly dependent on the methodology employed. Thus, we recommend an alteration to previously proposed methods in order to calculate the DPAO fraction through anaerobic-anoxic and anaerobic-aerobic batch tests. This information is expected to be valuable in studies focussed on optimising the amount of phosphorus removal achieved with simultaneous denitrification.

Applicability of experience from laboratory reactors with biological phosphorus removal in full-scale plants

2006 ◽  
Vol 54 (1) ◽  
pp. 267-275 ◽  
Author(s):  
E. Tykesson ◽  
L.L. Blackall ◽  
Y. Kong ◽  
P.H. Nielsen ◽  
J. la Cour Jansen
Keyword(s):  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
In Situ Hybridisation ◽  
Full Scale ◽  
Fluorescence In Situ Hybridisation ◽  
Biological Phosphorus Removal ◽  
Batch Tests ◽  
P Release ◽  
Biological Phosphorus

Enhanced biological phosphorus removal (EBPR) has been used at many wastewater treatment plants all over the world for many years. In this study a full-scale sludge with good EBPR was tested with P-release batch tests and combined FISH/MAR (fluorescence in situ hybridisation and microautoradiography). Proposed models of PAOs and GAOs (polyphosphate- and glycogen-accumulating organisms) and microbial methods suggested from studies of laboratory reactors were found to be applicable also on sludge from full-scale plants. Dependency of pH and the uptake of both acetate and propionate were studied and used for calculations for verifying the models and results from microbial methods. All rates found from the batch tests with acetate were higher than in the batch tests with propionate, which was explained by the finding that only those parts of the bacterial community that were able to take up acetate anaerobically were able to take up propionate anaerobically.

scholarly journals Rapid Multi-Hybridisation FISH Screening for Balanced Porcine Reciprocal Translocations Suggests a Much Higher Abnormality Rate Than Previously Appreciated

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 250
Author(s):  
Rebecca E O’Connor ◽  
Lucas G Kiazim ◽  
Claudia C Rathje ◽  
Rebecca L Jennings ◽  
Darren K Griffin
Keyword(s):  
Semen Analysis ◽  
In Situ Hybridisation ◽  
Economic Loss ◽  
Environmental Damage ◽  
Fluorescence In Situ Hybridisation ◽  
Reciprocal Translocations ◽  
Chromosome Translocations ◽  
Farrowing Rate ◽  
Significant Economic Loss

With demand rising, pigs are the world’s leading source of meat protein; however significant economic loss and environmental damage can be incurred if boars used for artificial insemination (AI) are hypoprolific (sub-fertile). Growing evidence suggests that semen analysis is an unreliable tool for diagnosing hypoprolificacy, with litter size and farrowing rate being more applicable. Once such data are available, however, any affected boar will have been in service for some time, with significant financial and environmental losses incurred. Reciprocal translocations (RTs) are the leading cause of porcine hypoprolificacy, reportedly present in 0.47% of AI boars. Traditional standard karyotyping, however, relies on animal specific expertise and does not detect more subtle (cryptic) translocations. Previously, we reported development of a multiple hybridisation fluorescence in situ hybridisation (FISH) strategy; here, we report on its use in 1641 AI boars. A total of 15 different RTs were identified in 69 boars, with four further animals XX/XY chimeric. Therefore, 4.5% had a chromosome abnormality (4.2% with an RT), a 0.88% incidence. Revisiting cases with both karyotype and FISH information, we reanalysed captured images, asking whether the translocation was detectable by karyotyping alone. The results suggest that chromosome translocations in boars may be significantly under-reported, thereby highlighting the need for pre-emptive screening by this method before a boar enters a breeding programme.

Monitoring HIV-1 treatment in immune-cell subsets with ultrasensitive fluorescence-in-situ hybridisation

The Lancet ◽  
1999 ◽  
Vol 353 (9148) ◽  
pp. 211-212 ◽  
Author(s):  
Bruce K Patterson ◽  
Mary Ann Czerniewski ◽  
John Pottage ◽  
Michelle Agnoli ◽  
Harold Kessler ◽  
...  
Keyword(s):  
Immune Cell ◽  
In Situ Hybridisation ◽  
Fluorescence In Situ Hybridisation ◽  
Immune Cell Subsets ◽  
Hiv 1

Assignment of the human slow skeletal muscle troponin gene (TNNI1) to 1q32 by fluorescence in situ hybridisation

1993 ◽  
Vol 62 (2-3) ◽  
pp. 181-182 ◽  
Author(s):  
H.J. Eyre ◽  
P.A. Akkari ◽  
C. Meredith ◽  
S.D. Wilton ◽  
D.C. Callen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
In Situ Hybridisation ◽  
Fluorescence In Situ Hybridisation ◽  
Slow Skeletal Muscle
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