from indigenous fermented foods and human gut ... - Thapar University

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Chapter I: Introduction
probiotic Lactobacillus candidates, which can be used in functional foods and to characterize
the strains in vitro as an initial part in their development, in order to elucidate their possible
mechanisms of probiotic action. The procedure to achieve this goal was to isolate lactic acid
bacteria from traditional fermented foods and children’s faeces followed by selection of the
strains which can survive under simulated gastrointestinal conditions and to accurately
identify them by phenotypic and genotypic methods via a polyphasic taxonomic approach.
The selected strains were screened for the technological and probiotic properties namely:
antimicrobial activities against pathogens, presence of β-galactosidase and bile salt hydrolase,
cholesterol removal, antibiotic resistance and surface properties including adhesion to the gut
mucosa. Based on the evaluation of above screens, the next step was to recommend those
selected strains for further probiotic development and to demonstrate functionality of
bacteriocins in food matrix, as well as in selected processing and post processing studies with
a view of commercial application.
The objectives of the present investigations are:
� Isolation and characterization of lactobacilli from indigenous fermented food with
probiotic attributes
� Evaluation of bacteriocin as a function of pathogen exclusion by selected probiotic
isolate and to elucidate their structure of action
� Evaluation of the function of bacteriocin in food matrix and post processing