Characterization, phylogenetic affiliation and probiotic properties of high cell density Lactobacillus strains recovered from silage.

BACKGROUND

The aim of the present study was to isolate high cell density Lactobacillus (LAB) from different forages and select the best strains for production of silage with improved the lactic acid production.

RESULTS

Twenty heterofermentative LAB strains were selected and their probiotic properties were analyzed by evaluating their tolerance to low pH, bile salts, biogenic amine production, enzyme activity, antibiotic susceptibility pattern and antifungal activity. The 16S rRNA gene-based phylogenetic affiliation indicated that 16 strains were Lactobacillus plantarum and others were L. bobalius, L. zymae, L. crustorum and L. diolivorans. Shake-flask cultivation of these strains under aerobic conditions showed comparatively higher growth and organic acid production than that achieved using the well-studied LAB strains. In addition, all the strains were highly sensitive towards ox gall (0.3%), but grew well in the presence of sodium taurocholate (0.3%). Antimicrobial susceptibility pattern is an intrinsic feature of these LAB strains; thus consumption does not represent a health risk to humans. Lactobacillus plantarum strains exhibited considerable antifungal activity against food pathogens.

CONCLUSION

The present finding raises the possibility that high cell density LAB strains with potential probiotic properties could be used to prepare quality silages for animals.