Moreover, discharging inefficiently treated wastewater to the environment results in environmental and health problems such as eutrophication, oxygen consumption, and toxicity ( Ding et al., 2011). However, conventional wastewater treatment processes do not guarantee disinfection and elimination of these organisms ( Howard et al., 2004). Industrial, agricultural, and domestic wastewater must be treated to eliminate pathogenic microorganisms and prevent their transmission through the environment. 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. The same trend was observed for treatment at 81.94 mA. At 90 s of exposure, all groups were affected except for Pseudomonas sp. 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. Conversely, all bacterial groups were completely eliminated by treatment at 85.34 mA for either 60 or 90 s. putida survived treatment at 81.94 mA for 90 s. However, when exposure time was extended to 90 s, only Escherichia coli, Coliforms, Aeromonas sp., Vibrio sp., and Pseudomonas putida survived. 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. DGGE revealed that the bacterial community gradually changed and overall abundance decreased to extinction upon plasma treatment. Three doses of atmospheric pressure dielectric barrier discharge plasma were applied to wastewater samples on different time scales. 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. 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 use of cold plasma jets for inactivation of a variety of microorganisms has recently been evaluated via culture-based methods. 5Physics Department, Faculty of Science, Beni-Suef University, Beni Suef, Egypt.4Physics Department, Faculty of Science, Taibah University, Almadinah Almunawarah, Saudi Arabia.3Botany and Microbiology Department, Faculty of Science, Cairo University, Giza, Egypt.

2Microbiology Department, Faculty of Science, Ain Shams University, Cairo, Egypt.1Biology Department, Faculty of Science, Taibah University, Almadinah Almunawarah, Saudi Arabia.

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