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Deterioration to extinction of wastewater bacteria by non-thermal atmospheric pressure air plasma as assessed by 16S rDNA-DGGE fingerprinting.

El-Sayed WS, Ouf SA, Mohamed AA - Front Microbiol (2015)

Bottom Line: Conversely, all bacterial groups were completely eliminated by treatment at 85.34 mA for either 60 or 90 s.The same trend was observed for treatment at 81.94 mA.The variability in bacterial community response to different plasma treatment protocols revealed that plasma had a selective impact on bacterial community structure at lower doses and potential bactericidal effects at higher doses.

View Article: PubMed Central - PubMed

Affiliation: Biology Department, Faculty of Science, Taibah University Almadinah Almunawarah, Saudi Arabia ; Microbiology Department, Faculty of Science, Ain Shams University Cairo, Egypt.

ABSTRACT
The use of cold plasma jets for inactivation of a variety of microorganisms has recently been evaluated via culture-based methods. Accordingly, elucidation of the role of cold plasma in decontamination would be inaccurate because most microbial populations within a system remain unexplored owing to the high amount of yet uncultured bacteria. The impact of cold atmospheric plasma on the bacterial community structure of wastewater from two different industries was investigated by metagenomic-based polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) utilizing 16S rRNA genes. Three doses of atmospheric pressure dielectric barrier discharge plasma were applied to wastewater samples on different time scales. DGGE revealed that the bacterial community gradually changed and overall abundance decreased to extinction upon plasma treatment. The bacterial community in food processing wastewater contained 11 key operational taxonomic units that remained almost completely unchanged when exposed to plasma irradiation at 75.5 mA for 30 or 60 s. However, when exposure time was extended to 90 s, only Escherichia coli, Coliforms, Aeromonas sp., Vibrio sp., and Pseudomonas putida survived. Only E. coli, Aeromonas sp., Vibrio sp., and P. putida survived treatment at 81.94 mA for 90 s. Conversely, all bacterial groups were completely eliminated by treatment at 85.34 mA for either 60 or 90 s. Dominant bacterial groups in leather processing wastewater also changed greatly upon exposure to plasma at 75.5 mA for 30 or 60 s, with Enterobacter aerogenes, Klebsiella sp., Pseudomonas stutzeri, and Acidithiobacillus ferrooxidans being sensitive to and eliminated from the community. At 90 s of exposure, all groups were affected except for Pseudomonas sp. and Citrobacter freundii. The same trend was observed for treatment at 81.94 mA. The variability in bacterial community response to different plasma treatment protocols revealed that plasma had a selective impact on bacterial community structure at lower doses and potential bactericidal effects at higher doses.

No MeSH data available.


Related in: MedlinePlus

Denaturing gradient gel electrophoresis (DGGE) profiles of 16S rDNA amplified from genomic DNA for untreated and plasma-treated wastewater samples. (A) Samples from the food processing industry. (B) Samples from the leather industry. Faint DGGE bands representing polymerase chain reaction (PCR) artifacts were neglected.
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Figure 5: Denaturing gradient gel electrophoresis (DGGE) profiles of 16S rDNA amplified from genomic DNA for untreated and plasma-treated wastewater samples. (A) Samples from the food processing industry. (B) Samples from the leather industry. Faint DGGE bands representing polymerase chain reaction (PCR) artifacts were neglected.

Mentions: Denaturing gradient gel electrophoresis profiles of the bacterial communities for the original untreated wastewaters from two different sources were determined. Eleven major DGGE bands designated as DGGE-A1-11 were detected in the food processing wastewater (Figure 5A). The affiliations of these OTUs were determined by comparison of their 16S rRNA gene sequences with those in the GenBank database (Table 1). Sequence analysis of the selected DGGE bands revealed the predominance of OTUs affiliated with Gammaproteobacteria. Identification of predominant OTUs revealed the presence of different bacterial species including E. coli (DGGE-A1), Klebsiella pneumoniae (DGGE-A2), Coliforms (DGGE-A3), Aeromonas sp. (DGGE-A4, A5, A7), Vibrio sp. (DGGE-A6), Pseudomonas sp. (DGGE-A8, A9, A11) and an uncultured bacterium (DGGE-A10).


Deterioration to extinction of wastewater bacteria by non-thermal atmospheric pressure air plasma as assessed by 16S rDNA-DGGE fingerprinting.

El-Sayed WS, Ouf SA, Mohamed AA - Front Microbiol (2015)

Denaturing gradient gel electrophoresis (DGGE) profiles of 16S rDNA amplified from genomic DNA for untreated and plasma-treated wastewater samples. (A) Samples from the food processing industry. (B) Samples from the leather industry. Faint DGGE bands representing polymerase chain reaction (PCR) artifacts were neglected.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4594161&req=5

Figure 5: Denaturing gradient gel electrophoresis (DGGE) profiles of 16S rDNA amplified from genomic DNA for untreated and plasma-treated wastewater samples. (A) Samples from the food processing industry. (B) Samples from the leather industry. Faint DGGE bands representing polymerase chain reaction (PCR) artifacts were neglected.
Mentions: Denaturing gradient gel electrophoresis profiles of the bacterial communities for the original untreated wastewaters from two different sources were determined. Eleven major DGGE bands designated as DGGE-A1-11 were detected in the food processing wastewater (Figure 5A). The affiliations of these OTUs were determined by comparison of their 16S rRNA gene sequences with those in the GenBank database (Table 1). Sequence analysis of the selected DGGE bands revealed the predominance of OTUs affiliated with Gammaproteobacteria. Identification of predominant OTUs revealed the presence of different bacterial species including E. coli (DGGE-A1), Klebsiella pneumoniae (DGGE-A2), Coliforms (DGGE-A3), Aeromonas sp. (DGGE-A4, A5, A7), Vibrio sp. (DGGE-A6), Pseudomonas sp. (DGGE-A8, A9, A11) and an uncultured bacterium (DGGE-A10).

Bottom Line: Conversely, all bacterial groups were completely eliminated by treatment at 85.34 mA for either 60 or 90 s.The same trend was observed for treatment at 81.94 mA.The variability in bacterial community response to different plasma treatment protocols revealed that plasma had a selective impact on bacterial community structure at lower doses and potential bactericidal effects at higher doses.

View Article: PubMed Central - PubMed

Affiliation: Biology Department, Faculty of Science, Taibah University Almadinah Almunawarah, Saudi Arabia ; Microbiology Department, Faculty of Science, Ain Shams University Cairo, Egypt.

ABSTRACT
The use of cold plasma jets for inactivation of a variety of microorganisms has recently been evaluated via culture-based methods. Accordingly, elucidation of the role of cold plasma in decontamination would be inaccurate because most microbial populations within a system remain unexplored owing to the high amount of yet uncultured bacteria. The impact of cold atmospheric plasma on the bacterial community structure of wastewater from two different industries was investigated by metagenomic-based polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) utilizing 16S rRNA genes. Three doses of atmospheric pressure dielectric barrier discharge plasma were applied to wastewater samples on different time scales. DGGE revealed that the bacterial community gradually changed and overall abundance decreased to extinction upon plasma treatment. The bacterial community in food processing wastewater contained 11 key operational taxonomic units that remained almost completely unchanged when exposed to plasma irradiation at 75.5 mA for 30 or 60 s. However, when exposure time was extended to 90 s, only Escherichia coli, Coliforms, Aeromonas sp., Vibrio sp., and Pseudomonas putida survived. Only E. coli, Aeromonas sp., Vibrio sp., and P. putida survived treatment at 81.94 mA for 90 s. Conversely, all bacterial groups were completely eliminated by treatment at 85.34 mA for either 60 or 90 s. Dominant bacterial groups in leather processing wastewater also changed greatly upon exposure to plasma at 75.5 mA for 30 or 60 s, with Enterobacter aerogenes, Klebsiella sp., Pseudomonas stutzeri, and Acidithiobacillus ferrooxidans being sensitive to and eliminated from the community. At 90 s of exposure, all groups were affected except for Pseudomonas sp. and Citrobacter freundii. The same trend was observed for treatment at 81.94 mA. The variability in bacterial community response to different plasma treatment protocols revealed that plasma had a selective impact on bacterial community structure at lower doses and potential bactericidal effects at higher doses.

No MeSH data available.


Related in: MedlinePlus