Plantaricin LD1 purified from Lactobacillus plantarum LD1 inhibits biofilm formation of Enterococcus faecalis ATCC 29212 in tooth model.

ABSTRACT

Plantaricin LD1 was purified to homogeneity using activity-guided chromatography. Enterococcus faecalis ATCC 29212 was found to be sensitive to plantaricin LD1 showing 13 ± 0·21 mm zone of growth inhibition. The minimum inhibitory concentration (MIC) was found to be 50 µg ml-1 against Ent. faecalis ATCC 29212. The in vitro biofilm formation by Ent. faecalis ATCC 29212 was observed, which was completely inhibited in the presence of bacteriocin. Similarly, biofilm formation was also observed on the teeth surface showing purple colour, whereas treated-teeth were clean and indicated no biofilm formation. Further, untreated cells of Ent. faecalis ATCC 29212 were found normal and plantaricin LD1-treated cells were ruptured when seen under light microscope, suggesting killing of target cells. These findings have proven the initial leads for antimicrobial and anti-biofilm activity of plantaricin LD1 against Ent. faecalis and its possible application for the treatment of endodontic diseases.