scholarly journals - The Choice of PCR Primers Has Great Impact on Assessments of Bacterial Community Diversity and Dynamics in a Wastewater Treatment Plant

2016 ◽  
pp. 82-127
Keyword(s):  
Wastewater Treatment ◽  
Bacterial Community ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Pcr Primers ◽  
Community Diversity ◽  
Bacterial Community Diversity

scholarly journals Effect of Wastewater Treatment Plant Effluent on Microbial Function and Community Structure in the Sediment of a Freshwater Stream with Variable Seasonal Flow

2008 ◽  
Vol 74 (9) ◽  
pp. 2659-2668 ◽  
Author(s):  
Steven A. Wakelin ◽  
Matt J. Colloff ◽  
Rai S. Kookana
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Bacterial Community ◽  
16S Rrna ◽  
Wastewater Treatment Plant ◽  
Bacterial Communities ◽  
Nutrient Loading ◽  
Treatment Plant ◽  
Biogeochemical Cycling ◽  
Rrna Genes

ABSTRACT We investigated the effects of wastewater treatment plant (WWTP) discharge on the ecology of bacterial communities in the sediment of a small, low-gradient stream in South Australia. The quantification of genes involved in the biogeochemical cycling of carbon and nitrogen was used to assess potential impacts on ecosystem functions. The effects of disturbance on bacterial community structure were assessed by PCR-denaturing gradient gel electrophoresis of 16S rRNA genes, and clone library analysis was used to phylogenetically characterize significant shifts. Significant (P < 0.05) shifts in bacterial community structures were associated with alteration of the sediment's physicochemical properties, particularly nutrient loading from the WWTP discharge. The effects were greatest at the sampling location 400 m downstream of the outfall where the stream flow is reduced. This highly affected stretch of sediment contained representatives of the gammaproteobacteria that were absent from less-disturbed sites, including Oceanospirillales and Methylococcaceae. 16S rRNA gene sequences from less-disturbed sites had representatives of the Caulobacteraceae, Sphingomonadaceae, and Nitrospirae which were not represented in samples from disturbed sediment. The diversity was lowest at the reference site; it increased with proximity to the WWTP outfall and declined toward highly disturbed (400 m downstream) sites (P < 0.05). The potential for biological transformations of N varied significantly with the stream sediment location (P < 0.05). The abundance of amoA, narG, and nifH genes increased with the distance downstream of the outfall. These processes are driven by N and C availability, as well as redox conditions. Together these data suggest cause and effect between nutrient loading into the creek, shift in bacterial communities through habitat change, and alteration of capacity for biogeochemical cycling of N.

scholarly journals Mobilizable IncQ-Related Plasmid Carrying a New Quinolone Resistance Gene, qnrS2, Isolated from the Bacterial Community of a Wastewater Treatment Plant

2006 ◽  
Vol 50 (9) ◽  
pp. 3075-3080 ◽  
Author(s):  
Gabriele Bönemann ◽  
Michael Stiens ◽  
Alfred Pühler ◽  
Andreas Schlüter
Keyword(s):  
Wastewater Treatment ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Resistance Gene ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
The United States ◽  
Replication Initiation ◽  
Quinolone Resistance ◽  
Selection Strategy

ABSTRACT Plasmid-encoded quinolone resistance was previously reported for different bacteria isolated from patients not only in the United States and Asia but also in Europe. Here we describe the isolation, by applying a new selection strategy, of the quinolone resistance plasmid pGNB2 from an activated sludge bacterial community of a wastewater treatment plant in Germany. The hypersensitive Escherichia coli strain KAM3 carrying a mutation in the multidrug efflux system genes acrAB was transformed with total plasmid DNA preparations isolated from activated sludge bacteria and subsequently selected on medium containing the fluoroquinolone norfloxacin. This approach resulted in the isolation of plasmid pGNB2 conferring decreased susceptibility to nalidixic acid and to different fluoroquinolones. Analysis of the pGNB2 nucleotide sequence revealed that it is 8,469 bp in size and has a G+C content of 58.2%. The plasmid backbone is composed of a replication initiation module (repA-repC) belonging to the IncQ-family and a two-component mobilization module that confers horizontal mobility to the plasmid. In addition, plasmid pGNB2 carries an accessory module consisting of a transposon Tn1721 remnant and the quinolone resistance gene, qnrS2, that is 92% identical to the qnrS gene located on plasmid pAH0376 from Shigella flexneri 2b. QnrS2 belongs to the pentapeptide repeat protein family and is predicted to protect DNA-gyrase activity against quinolones. This is not only the first report on a completely sequenced plasmid mediating quinolone resistance isolated from an environmental sample but also on the first qnrS-like gene detected in Europe.

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