ABSTRACT

The aim ofthe study is the effect of probiotics in fermented foods sold in Umuahia, Abia State.A total five (5) fermented food samples sold in Umuhaia, Abia State was purchased from different market locations and was taken to the Microbiological laboratory for Analysis. 1ml of each ofthe dilutions was inoculated by spread method on MRS agar. They were incubated at 37°C for 24 hours. The plates were observed for presence of growth and the colonial characteristics were taken. The biochemical characteristics of isolates, revealed the genera of Streptococcus thermophilus. Bacillus subtilis, Lactobacillus plantarum, Bacillus lichenformis and Enterococcus sp. The total viable count of Lab isolates from the fermented foods had Ogi ranged from 2.0 xlO6 to 7.2 x 106. The effect of bile concentration on probiotic bacteria. Bifidobacterium bifidum 92.2 had the highest ranged while Bifidobacterium infantis 66.9 had the lowest concentration. Lactobacillus plantarum and Bifidobacterium infantis had the highest zone ofinhibitory on all the pathogenic organisms. Streptococcus thermophilus exhibited lowest zone of inhibition on Escherichia coli (0mm). Antibacterial activity of Streptococcus thermophilus against Staphylococcus aureus, Salmonella spp and Shigella spp showed lowest zones ofinhibition. The percentage occurrences of bacterial isolates. Lactobacillus rhamnosus has a high percentage occurrence of 52.9% followed by lactobacillus plantarumZS.yYo, Bifidobacterium infantis 19.6%, Bifidobacterium bifidum\5.'l°/o and Streptococcus thermophilus 11.7%. The determination of cholesterol capacity ofthe bacterial isolates. Lactobacillus plantarum had 76.43 while Streptococcus spp had 6.02. The determination of acid tolerance of isolates .Lactobacillus rhamnosus and Bifidobacterium bifidum had profuse growth while Streptococcus thermophilus had a good growth. Lactobacillus plantarum has been shown to be the most effective probiotic which exerted the highest antimicrobial effect against the test pathogens. Lactic acid bacteria from fermented foods may act as a reservoir of antimicrobial resistance genes. These bacteria could act as biotherapeutic microorganisms and might be good probiotic.