الفهرس 
Introduction and Aim of workOnly 14 pages are availabe for public view
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Abstract
Studying the antimicrobial activity of some fermented beverages such as kefir and kombucha against a number of pathogenic microorganisms is the aim of the current investigation , these microorganisms including E.coli ATCC11229, P.aeruginosa ATCC27853, K. pneumoniae ATCC13883, S. aureus ATCC6538, Sal. typhi ATCC14028, Asp. flavus ATCC16872, Asp. niger ATCC20611, Penicillium sp. (our strain collection) and C. albicans ATCC 10231 were selected for our study because such pathogens exert negative impact and a harmful effect on human health. All pathogens were sensitive to either fermented kombucha or kefir even at neutral pH. These conclusions are paramount that the antimicrobial activity is not only due to acids, large proteins or catechins are very likely due to metabolites produced by bacteria and yeasts during the fermentation process. In the present study, kefir and kombucha beverage were used in combination with some medicinal plants extracts that exert a synergistic effect against pathogens threating human health. Garlic, ginger, pomegranate and mint were selected for our study. Both of our natural agents (kefir and kombucha) completely reduced the viable cell counts singly or in combination with medicinal plant extracts which supported their use as alternatives to antibiotics and other chemotherapeutics which result in the presence of resistant strains of bacteria.
One way to summarize the results obtained is as follows:
1. The antimicrobial activity of milk kefir suspension (fermented kefir suspension and neutralized kefir) against both bacteria and fungi was conducted by well diffusion method in the current study. Fermented KB showed the highest antibacterial activity with inhibition zones equal to 21 and 20 mm against S. aureus ATCC6538 and P. aeruginosa ATCC27853 respectively.
2. On the other hand, fermented KB showed the highest antifungal effect on growth of Asp .niger ATCC20611 and Penicillium sp. (our strain collection) where the recorded inhibition zones were19 and 17 mm respectively.
3. Viable counts of staph. aureus ATCC6538 and p. aeruginosa ATCC27853 were adjusted to 5.7x102 CFU/mL indicating dangerous limit of these microorganisms
4. In the present study, fermented KB was examined for its inhibitory activity combined with medicinal plant extracts including garlic, ginger, pomegranate and mint and testing them for being bactericidal to pathogenic microorganisms.
5. The viable cell counts of pathogenic microorganisms in these combinations decreased gradually and no growth was detected after certain time.
6. In case of garlic cloves extract, no growth of S. aureus was recorded after 48h in sample of garlic cloves extract treated by 4% KB and no growth of these bacteria after 72, 96h in sample of garlic treated by (2, 4%) KB but for P. aeruginosa that was recorded no growth after 72, 96h with (2, 4%) KB.
7. The viable cell counts of pathogenic microorganisms in ginger rhizomes extract decreased gradually and no growth of S. aureus (P. value= 0.000) was detected after 24, 48h in sample treated by 4% KB ; no growth was detected after 72, 96h in sample treated by (2, 4%) KB but P. aeruginosa detected; no growth after 48h when treated with 4% and no growth also after 72, 96h when treated with (2, 4%)KB.
8. The viable cell counts of pathogenic microorganisms in pomegranate extract decreased gradually and no growth of S. aureus; was recorded after 72, 96h in sample treated by 4%KB and no growth after 96h in sample treated with 2%KB and Pseudomonas aeruginosa recorded no growth after 96h in sample treated with 4% KB.
9. The viable cell counts of pathogenic microorganisms in mint extract decreased gradually and no growth of both S. aureus and P. aeruginosa was recorded after 72h in sample treated by 4%KB; no growth was recorded after 96h for both samples treated by 2, 4% KB.
10. Biochemical analysis of fermented KB was carried out by HPLC analysis that detected 7 organic acids (Formic, Lactic, Acetic, Citric, Succinic, Propionic and Butyric) which play an important role in bacterial cell membrane acidification leading to cell death and the other strong effect on fungal strains.
11. In this study , The antimicrobial activity of two black tea beverages ( fermented , neutralized ) against the pathogenic microorganisms was carried out and revealed that fermented tea beverages was the most effective against all tested pathogens than other treatment ( neutralized ) . S. aureus ATCC6538 showed the highest response to fermented beverage with inhibition zone diameter 16 mm followed by P. aeruginosa ATCC27853 with inhibition zone 15 mm.
12. It was also indicated that pathogenic fungi including Candida albicans ATCC 10231 was sensitive to fermented kombucha beverage with inhibition zone of 15mm and the lowest inhibition by Asp. flavus ATCC16872 of about 12mm.
13. Studies were further extended to control growth of the previously mentioned pathogenic microorganisms with fermented kombucha beverage prepared at different concentrations.
14. In the present study, fermented KFB was examined for its inhibitory activity by testing it with medicinal plant extracts including garlic, ginger, pomegranate and mint and testing them for being bactericidal to the food borne pathogens. The viable cell counts of pathogenic microorganisms in this combinations decreased gradually and no growth was detected after certain time.
15. The viable cell counts of pathogenic microorganisms in garlic extract decreased gradually and no growth was detected after treatment with 2, 4% KFB after 96h for S. aureus and P. aeruginosa and no growth can be detected after 72h when extract treated with 4% KFB for P. aeruginosa.
16. In case of ginger extract, complete inhibition of viable cells was achieved after 48h when extract treated with 4% KFB and 72, 96h in treatment with( 2, 4%) for Pseudomonas aeruginosa . No growth detected for S. aureus after 72h when extract treated with 4%KFB and after 96h when treated with 2, 4% KFB.
17. The viable cell counts of pathogenic microorganisms in pomegranate extract decreased gradually and no growth was detected after 72, 96h for S. aureus when treated with 4% KFB and after 48h for Pseudomonas aeruginosa when treated by 4%KFB and after 72, 96h when treated by (2, 4%)KFB.
18. The viable cell counts of pathogenic microorganisms in mint extract decreased gradually and no growth of S. aureus after 96h when extract treated with 4% KFB and Pseudomonas aeruginosa was recorded after 72h when extract treated with 4%KFB and recorded after 96h when treated by 2, 4% KFB.
19. Biochemical analysis of kefir and kombucha beverages were carried out by HPLC analysis that was giving rise to 7 organic acids which eluted at different retention times. These organic acids exert strong antimicrobial effect with each other against bacterial and fungal strains.
20. Biochemical analysis of medicinal plant extracts were carried out for (garlic and mint) by GC-MS, and for (ginger and pomegranate) by HPLC .Analysis of garlic was resulting in the production of 18 compounds (essential oils) that play an important role in inhibition of pathogens, about 27 compounds (essential oils) for mint extract that affect with sparkling way against pathogens.
21. For HPLC analysis of ginger and pomegranate that detected 19 essential phenolic compounds affect with each other against microbes.
22. For further bioactive compounds, LC-MS analysis was carried out for ginger extract that resulted in the production of 10 essential compounds play sparkling effect on bacterial and fungal strains tested in this study.