Lyophilisation of lactic bacteria with probiotic effect for production of starter cultures

Abstract

Selection of lactic acid bacteria (LAB) for probiotic effect and preservation of LAB by lyophilized have been studied. The two LAB strains belonging to Lactobacillus plantarum and Lactobacillus pentosus producing bacteriocins in inhibitory concentration for colibacilli were selected from a total of 17 tested strains. The selected strains were further tested for their ability to survive the preservation process by lyophilisation. Two methods of preserving LAB by lyophilisation were tested and the viability of cells in lyophilized products was monitored in order to obtain products used as starter cultures. The presence of inhibition zones in mixt cultures indicates the ability of LAB to inhibit the growth of E. coli bacteria due to the synthesis of bacteriocins. During three years period, the viability of lyophilized LAB was monitored. Obtained data indicate that starter cultures of LAB can be stored in the lyophilized state for at least three years in dark and cool place, and the inoculation rate can be increased after this period by 50% if the starter culture was preserved and stored by applying the described techniques.