Probiotic characteristics of Lactobacillus acidophilus strains isolated from fermented milk

Ten strains of Lactobacillus acidophilus selected out of a total of 273 strains of lactobacilli isolated from marketed sour (dahi) curd samples were studied for certain probiotic characteristics to use them as probiotic culture in preparation of fermented dairy products. All the selected strains exhibited pronounced antibacterial activity against a human enteropathogenic strain of Escherichia coli; the maximum zone of inhibition (10 mm) was observed with Lb. acidophilus E-30(.) The strains were resistant to gastric acidity. However, none of the strains could grow at pH 2.0. Study on the growth of the Lb. acidophilus strains revealed that most of them attained maximum growth at 24 h of incubation at 37 degrees C. Maximum viable count of 9.2 log(10)cfu/ml was recorded for Lb. acidophillis E-30. Appreciable body weight gain of albino mice fed with selected strains of these cultures was recorded. Maximum weight gain of 7.5 g was recorded for strain Lb. acidophilus E-1.