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Ozone efficiency in the water treatment systems is widely published in national and international papers. The criteria design of the treatment plants have changed over the years with increasing knowledge about the mechanism through which ozone reacts with chemical and microbiological pollutants. It recognizes the existence of a relationship between morphological and physiological characteristics of microorganisms and their resistance to ozone. However, there are few studies reported about the mechanisms by which ozone inactivates microorganisms in aqueous media. The aim of this study was to evaluate the effect of ozone on cytoplasmic membrane and enzymes related to oxidative balance on two microorganisms: Escherichia coli ATCC 25922 and Salmonella enterica var. Thyphimurium ATCC 12 048. From a kinetic study was determined, the variation of the efflux of potassium, changes in SH groups and the action exerted by ozone on the enzymes catalase and superoxide dismutase. The results showed an involvement of SH groups present, mainly, in protein and the potassium efflux outside microbial cells, demonstrating that these compound are among the first targets of ozone on microorganisms. An increased activity of the catalase enzyme and a decreased activity of superoxide dismutase enzyme were observed. The decrease in the relationship between these two enzymes suggests that the antioxidant systems of microorganisms are not able to counteract the damage caused by ozone. [ABSTRACT FROM AUTHOR]

Introduction: Ozonized Sunflower Oil (OLEOZON ) is a registered drug developed at the Cuban Ozone Research Center and successfully employed in the treatment of different infection diseases. It is generally accepted, that the antimicrobial activity of ozonized vegetable oils it is related to the action of peroxidic compounds formed during ozone-vegetable oil reaction. The main targets of these peroxides on microorganism could be unsaturated lipids and proteins containing sulphydryl groups. Material and Methods: In this work, the polar fraction of OLEOZON® was isolated by a silicagel column chromatography method and the components of polar fraction were isolated by thin layer chromatography (TLC) and molecular exclusion - high performance liquid chromatographic (RP-HPLC). The components of polar fraction were characterized by the combination of nuclear magnetic resonance spectroscopy (NMR) and electro spray mass spectrometry (ESI-MS). S. Aureus ATCC 25923 and P. Aeruginosa ATCC 27853 strains were used to evaluate the in vitro activity (minimal inhibitory and minimal bactericidal concentrations) of OLEOZON® and its polar fraction. The content of potassium ions released to media by bacterial cells was employed as a criterion of alteration of the cell membrane permeability. Also, the total sulphydryl groups and the total protein content were measured. Results and Discussion: In the polar fraction of OLEOZON® are concentrated the oxidant and polar compounds formed. Different results were found for the two studied microorganism related to the different bacterial membrane composition. Conclusion: The main action mechanism of OLEOZON® again S. Aureus and P. Aeruginosa it is related to oxidative attack of peroxidic compounds to microorganism membranes. [ABSTRACT FROM AUTHOR]

Ozonation of theobroma fat at different applied ozone dosages was carried out and peroxide indexes along with antimicrobial activity were determined. The reaction products were identified using Proton Nuclear Magnetic Resonance Spectroscopy (¹H NMR). The principal signal intensity values were used for following the reaction course between ozone and theobroma fat. The reaction was followed up to peroxide index values of 544 mmol-equiv/kg. The intensities of olefinic proton signals decreased with the gradual increase in ozone concentration until disappearing completely. The Criegee ozonides obtained at 87.4 mg/g of ozone doses were approximately 3.7 times higher than at the beginning of the reaction. The highest action spectrum of antimicrobial activity was obtained with the higher peroxide index. These results suggest that the ¹H NMR spectroscopic technique provides valuable information about of the ozonization grade of theobroma fat which produces an affective antimicrobial activity against Candida albicans. [ABSTRACT FROM AUTHOR]