Bioprospecting of Lactic Acid Bacteria for Potentiality as Probiotics

Lactic acid bacteria have been used for many years as natural bio preservatives in fermented foods and are also believed to have beneficial health effects on the host. However selection of strain is an important criteria which is mainly based on evaluating the physiological properties of the strain. In this study, lactic acid bacteria were isolated from various dairy, non-dairy and human sources in MRS agar medium and were characterized based on physiological and biochemical characteristics. Based on their tolerance to bile and to extreme low acid conditions, four isolates were selected. Their activity was tested against common food and human pathogens and the isolates were also tested for their sensitivity towards twelve different antibiotics. The screened isolates were subjected to high temperature and salinity and were also exposed to hydrogen peroxide since the isolates were catalase negative. The results ended up with two isolates, which were promising for development as suitable candidates for use in functional foods.