Cidní působení korónového výboje na mikroorganismy
Germicidal effects of corona discharge on microorganisms
diploma thesis (DEFENDED)
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http://hdl.handle.net/20.500.11956/1280Identifiers
Study Information System: 60926
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- Kvalifikační práce [20091]
Author
Advisor
Referee
Julák, Jaroslav
Faculty / Institute
Faculty of Science
Discipline
Teaching of Chemistry and Biology for Secondary Schools
Department
Department of Genetics and Microbiology
Date of defense
23. 9. 2008
Publisher
Univerzita Karlova, Přírodovědecká fakultaLanguage
Czech
Grade
Good
This thesis following up the studies about decontamination effects of low-temperature plasma generated by corona discharge. Two species of bacteria, Escherichia coli and Staphylococcus epidermidis, were exposed in two separate sets of experiments. Bacterial suspensions were treated by point-to-plane corona discharge directly on surface of semisolid culture medium, the Mueller-Hinton agar, placed in Petri Dishes of 5 cm diameter. The point electrode was realized by the tip of a 0.7 mm syringe needle, connected to the source of direct current high voltage. The plane electrode was formed by the surface of an ion-conducting semisolid cultivation medium. A micrometer screw allowed precise setting the 4 mm distance of the point electrode from the anode surface. The samples were exposed to the corona discharge with current of 25μA - 150μA range. The treatment duration is given by constant exposed charge (18, 27, 36 and 54 mC) condition. After exposition, all Petri dishes were immediately cultivated at 37 žC overnight. After cultivation followed evaluation of inhibition zone areas, that was caused by action of electric charge. The state of the cultures was quantitatively assessed by measuring of the growth inhibition zones, where a complete growth inhibition took place. The behaviors of these exposures were...