Characterization of Lactic Acid Bacteria Isolated from Dairy Products in Egypt as a Probiotic

Lactobacilli belong to lactic acid bacteria (LAB), generally recognized as safe primary fermentation end product from sugars is lactic acid and that is why foods are conserved. Lactic acid bacteria have been used for improving health host. Therefore, they are an important part of intestinal flora in human and animals as probiotic. This research aimed to isolate lactic acid bacteria with significant probiotic character from different dairy products. In this study, homo- fermentative LAB were isolated from different dairy products in Egypt. Isolates were identified by morphological, biochemical and physiological methods. Probiotic properties of isolates were investigated. The isolated bacteria were studied for antagonistic effects on clinically isolated E. coli, Salmonella spp. Micrococcus spp., Staphylococcus spp. A collection of fifty four isolates were obtained. Eight isolates from different dairy products were observed as potential probiotic safe for human use; where they found to be tolerant to low pH and bile salt and effective against isolated E. coli, Salmonella spp. Micrococcus spp. All isolates were screened for enzymatic activity using API ZYM Kits and antibiotic sensitivity. Biochemical and physiological results indicated that they were found to be related to the genus Lactobacillus and suggested to belong to L. casei (4 isolates), L. Acidophillus (3 isolates) and L. lactis(1 isolates) and that were effective on the isolated E. coli, Salmonella spp. Staphylococus spp. and they have enzymatic activity. beta-galactosidase was produced, which is beneficial for lactose intolerance. Lactobacillus spp. produced enzymes including leucinearylamidase, crystinearylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase, alpha-galactosidase, beta-galactosidase, alpha-glucosidase, beta-glucosidase, and N-acetyl-beta-glucosamidase so we concluded that human milk, yogurt and raw milk are considered a good source of potential probiotic strains also the isolated bacteria had no haemolytic activity so it consider as a great potential probiotic and safe for human use. [Rasha H. Bassyouni, Walla S. Abdel-all b, Mostafa G. Fadl Saed Abdel-all and Zeinat kamel. Characterization of Lactic Acid Bacteria Isolated from Dairy Products in Egypt as a Probiotic. Life Sci J 2012;9(4):2924-2933]. (ISSN: 1097-8135). http://www.lifesciencesite.com. 428