Isolation of potential probiotic Lactobacillus strains from human milk

ABOUT AUTHOR
Anandharaj.M*, Sivasankari.B
Department of Biology,
Gandhigram Rural Institute- Deemed University, Gandhigram, Dindigul, Tamilnadu, India.
E-mail:   anandhraj49@gmail.com

ABSTRACT
Probiotic is a live microbial supplement which affects host’s health positively by improving its intestinal microbial balance Probiotics are used for long times in food ingredients for human and also to feed the animals without any side effects. Also probiotics are acceptable because of being naturally in intestinal tract of healthy human and in foods. The Lactic acid bacteria (LAB) were isolated from fermented food products, dairy products, human intestine and feces but human breast milk is a natural source of potential Lactobacillus strains. Hence the present study was aimed to isolate and identify the Lactobacillus spp. from human milk and to test for acid tolerance, bile tolerance and antimicrobial activity. Totally 32 isolates were isolated and only two were identified as Lactobacillus spp. and named as LAB1 and LAB2. Results showed that a considerable variation existed among the bacterial cultures in their growth and viability in the presence of bile salt, and assimilation of cholesterol from the medium. Moreover, the strain LAB1 shown to be the most bile salt tolerant (0.5% and 1% concentration) culture and they grow well at low pH. The total plate count of LAB1 after 3 hours at pH 2 is 6.01 CFU/ml and it will decrease in pH 1.  The strain LAB1 inhibit the growth of Escherichia coli, Klebsiella pneumoniae and Candida albicans and produce 9.26±0.20, 10.33±0.57 and 6.69±1.23 mm zones around the wells respectively.
Key words : Probiotics, Mother’s milk, Lactobacillus spp, Escherichia coli, Candida albicans