Isolation, Identification and Study of Antimicrobial Property of Potential Probiotic Bacteria from Dairy Products of Lucknow City

Abstract

Probiotics are the nonpathogenic and alive bacteria that confer good effects on the host. The important property of probiotics is direct antimicrobial effects, stimulation of immunity, competing for adhesion site, completion for nutrients and improvement in digestion. Since ancient times different fermented dairy products have been used as the main source of probiotic bacteria. The main objective of this study was to isolate, identify and characterize lactic acid bacterial strains from different fermented dairy products including yoghurt, cheese, buttermilk and curd. To determine the potentials of probiotics different tests like bile tolerance, salt tolerance, acid tolerance and arginine hydrolysis were performed. In the present study it was observed that all the probiotic isolates were able to grow at low pH (2-6) and they were tolerant against NaCl (2%, 4%, 6%) and bile salt concentration (0.2%, 0.4%, 0.6%). The probiotic isolates were shown to be arginine-positive as on a white background they displayed a bright orange colour. The growths of probiotic cultures were observed at different temperature i.e 10 °C and 45°C and were able to ferment different types of carbohydrates such as glucose, sucrose and lactose. The probiotic isolates showed good antimicrobial activities against the four test organisms. The present study showed that the probiotic strains isolated from different fermented dairy products carry antimicrobial property and can be used to control gut microbiota. The observation of the present study showed that dairy products can be used as a good source of potentially probiotic bacteria.