APPLICATION OF DC ATMOSPHERIC PRESSURE PLASMA JETS FOR INACTIVATION OF MICROORGANISMS CONSORTIUMS

Experimental results for inactivation of microorganism test strains of S. aureus, E. coli, P. aeruginosa separately and in such consortium by air plasma jet are presented. For monocultures of S. aureus, E. coli, P. aeruginosa the characteristic D-times are practically the same and are around 1.5 min, while for the consortium these is 3 min.57-5

Test-model and quantitative rdds criterion index which are applied to estimate antimicrobic potential of nanomaterials used for water purification and treatment: Substantiation and metrologic assessment

To reduce population health risks which occur when people consume drinking water from centralized water supply systems is a vital medical-biologic and technical problem. It can be sold, among other things, via development and application of new materials for water purification and treatment. Some natural and artificial nanomaterials have antimicrobic properties as they can eliminate microorganisms of various taxonomy (bacteria, yeast-like and mold fungi) and bacterial biofilms. However, certain results which were obtained when antimicrobic potential of nanomaterials was estimated are controversial; they are frequently only qualitative or semi-quantitative due to absence of a standard test protocol and well-grounded criterial assessment apparatus. So, the goal of this paper was to give methodological grounds and to create a unified and standardized test-model; to optimize parameters of a procedure and to substantiate a system of criteria applied for quantitative assessment of antimicrobic activity which is characteristic for nanomaterials applied for water purification and treatment. The research was performed on the following objects: samples of nanomaterials based on titanium dioxide which were applied for water purification and treatment. The authors have substantiated a test-model, suggested a criterion index RDDS, made up a standard test protocol for quantitative assessment of antimicrobic potential possessed by nanomaterials. The developed technology has been tested on samples of nanomaterials based on titanium dioxide. We have calculated and assessed metrological parameters of the procedure (repeatability standard deviation and repeatability limit) which conform to the requirements existing for similar procedures when confidence probability is assumed to be equal to 95 %; such requirements are fixed by the ISO (International Standardization Organization) and correspond to the GLP (Good Laboratory Practice) principles. The relevance of the test-model was validated; this relevance provides an objective quantitative assessment of antimicrobic potential which is possessed by materials applied for disinfection of water objects contaminated with microbiota of various taxonomy, as well as for control and prevention of bacterial infections which can be communicated with water

APPLICATION OF DC ATMOSPHERIC PRESSURE PLASMA JETS FOR INACTIVATION OF MICROORGANISMS CONSORTIUMS

57-57Experimental results for inactivation of microorganism test strains of S. aureus, E. coli, P. aeruginosa separately and in such consortium by air plasma jet are presented. For monocultures of S. aureus, E. coli, P. aeruginosa the characteristic D-times are practically the same and are around 1.5 min, while for the consortium these is 3 min

Experimental modeling of aerosols produced by microorganisms in working area air as risk factor exerting hazardous impacts on health of workers employed at biotechnological production

Scientific foundation and practices in the sphere of hygienic and ecological standardization concerning biological factors of the environment have a number of peculiarities and are methodically less developed than chemical factors standardization. Efficient industrial control over maximum permissible concentrations of standardized microorganisms-producers in working area air is based on validated instrumental techniques of quantitative assessment. Our goal was to create experimental models for microorganisms-producers' aerosols of a multi-component microbe specimen in working area air as a risk factor causing impacts on health of workers employed at biotechnological production; another task was to work out a procedure for measuring Pseudomonas aurantiaca B-162/255.17concentration and cells and spores of Bacillus sp. BB58-3 strain in working area air. We gave grounds for a technology aimed at quantitative determination of microorganisms-producers in working area air in a modeling experiment; it was based on conventional stages and tech-niques accepted in microbiological practices, namely air samples taking via aspiration technique allowing for a volume taken; cultivation under conditions which are optimal for examined microorganisms-producers in a nutrient medium with reduced composition; calculation of evolved colonies with specific morphological features; morphologic identification of microorganisms and colonies; calculation of microorganisms' quantity on dishes with recalculation per 1 m3 of air. Bas-ing on the detected regular concentration dependences of microbe contamination dynamics in air we worked out a proce-dure for quantitative determination of microorganisms-producers; we also performed metrological estimate of opera-tional properties for assessing microorganisms-producers of a multi-component microbe specimen as a risk factor caus-ing hazardous impacts on health of workers employed at biotechnological production. We validated our measuring procedure in conformity with the requirements set forth by ISO

Experimental justification of indicative microbiological values for the safety of water bodies in the recreation areas

The article provides the assessment of the microbiological values of water bodies if they are used for recreational purposes and distinguishes the epidemiologically significant parameters. In order to validate the indicative safety values taking into account the existing conditions of the recreational use of water we conducted the hygienic assessment of water in the water bodies used for recreational purposes under the indicative microbiological values (total microbial count, thermotolerant coliform bacteria, E. coli; enterococcus, spores of sulfite-reducing Clostridia; coliphages; Ps. aeruginosa) and the content of pathogenic microorganisms; also the microbiological profile of water was identified. The obtained data will be used to improve the system for monitoring of water bodies in the recreation areas

EVALUATION OF ANTIMUTAGENIC AND ANTIFUNGAL PROPERTIES, PARAMETERS OF ACUTE TOXICITY AND SENSITIZING ACTIVITY OF ENZYMATIC WHEY PROTEIN HYDROLYSATE

Biologically active peptides with antioxidative, antibacterial, immunomodulating and other properties result from the reaction between the whey proteins and proteolytic enzymes of the gastrointestinal tract or purified proteases. This work aims to determine antimutagenic and antifungal effect of the enzymatic hydrolysate of whey protein obtained, to assess its acute toxicity characteristics and sensitizing power. Antimutagenic action of native whey proteins and hydrolysates (test sample and hydrolyzate analog) was assessed by the Ames test using indicator strains of Salmonella typhimurium ТА 98 and ТА 100. When determining the antifungal activity, opportunistic strains of Aspergillus niger and Candida albicans were used. The toxicity degree of samples was defined in studies to evaluate the acute intragastric toxicity in white rats as well as in the single abdominal dose study on the white mice. Irritating influence of whey proteins and peptides on was evaluated when applied to the eye mucosa of rabbits. The sensitizing capacity of samples was evaluated using the experimental model to reproduce the delayed hyperresponsiveness in white mice. It is identified that the developed hydrolisate is classified as the safe agent and has low sensitizing ability. The sample obtained has the comparative values of antioxidant and antimutagenic activity level as compared with the analog «Vital Аrmor H 801 LB» (Armor Proteines, France) used to manufacture functional products. The advantages of the hydrolisate developed include the increase in the content of peptide fraction and more pronounced antifungal activity towards A. niger