THE EFFECT OF PROBIOTIC BACTERIA AND PREBIOTICS ON THE GROWTH OF E.COLI ATCC23922 AND ENTEROCOCCUS FAECALIS ATCC 29212

Background and Aim:Intestine is the habitat of a large and diverse population of microbes,including a variety of anaerobic bacteria .these bacteria participate in the catabolismes of a wide range of compounds and generates secondary toxic compounds. Often these secondary compounds are toxic to the host.the consumption of probiotic bacteria and prebiotics in the diet can balance the number and the type of intestinal flora.Methods:In this study,100 microliter of 0.5 McFarland concentration of over night probiotic bacteria that grown in MRS broth (Lactobacillus acidophilus ATCC 4356,L.casei ATCC 39392, L.fermentum ATCC 9338 , L plantarum ATCC 8014 ,L.reuteri ATCC 2372,L.rhamnosus ATCC 7469) were incubated in three cultured medium ,pure MRS broth and MRS broth containing 2% w/v trehalose and MRS broth containing 2% w/v sorbitol.then after 48 hours,to obtain supernatant of probiotic bacteria,all cultures were centrifuged at 6000 rpm and -4 centigrade degree for 20 minutes and the supernatant was passed through a filter 0/22 micrometer and its effect on growth of E.coli ATCC23922 and Enterococcus faecalis ATCC 29212 was determied by MIC(minimum inhibitory concentration)and MBC(minimum bactericidal concentration).Results:The result showed that the MIC of free supernatant of L.casei that grown in MRS broth containing 2% w/v terhalose on E.coli and L.casei that grown in MRS broth containing 2% w/v sorbitol and L.casei that grown in control culture medium on Enterococcus faecalis were 12/5% .Conclusion:we can use L.casei s supernatant with Terhalose and Sorbitol as dietary supplement to modulation intestinal flora.

کلیدواژه ها:

probiotic ، prebiotic ، MIC-MBC ، Intestinal flora