Komalben J. Hirania*, Amar P. Garga & Sandeep K. Srivastavab
aSchool of Biological Engineering & Life Sciences, Shobhit Institute of Engineering & Technology, Deemed to-Be- University, Modipuram, Meerut, India
bCentre for Innovation, Research and Development, Dr. B. Lal Institute of Biotechnology, Jaipur, India.
Received : 16th July, 2022 ; Revised : 16th August, 2022
Abstract– The present study was carried out to isolate those probiotic strains of lactic acid bacteria (LAB) from human colostrum that possess antibacterial activity against wide range of human pathogens. All the isolates were biochemically characterized and studied for their probiotic properties including acid tolerance, production of bacteriocin and hydrogen peroxide, tolerance to different concentrations of bile salts and resistance against common antibiotics. Antibacterial activity of the isolated species was tested against different Gram’s negative as well as positive pathogens including Klebsiella pneumoniae, Proteus vulgaris, Staphylococcus aureus, Salmonella typhi, Escherichia coli and Pseudomonas aeruginosa. All isolates showed inhibitory effects against above mentioned bacteria. L15002 showed high antibacterial activity against all test pathogens. It was genotypically confirmed as Lactococcus lactis. The growth of bacteria was assessed in vitro using viable bacterial counting. Antibacterial response of Lactococcus lactis was attributed to the production of bacteriocins which were responsible for cell death as well as cell inhibition. The present study is focused on antagonistic activity of different species of LAB isolated from human colostrum.
Key words: Lactic acid bacteria, Probiotics, Bacteriocins, Antagonistic activity