# Optimization of the Purification Process for Lactiplantibacillus plantarum Lipoteichoic Acid with Anti-Biofilm Properties against Dental Pathogens

## TL;DR

This paper optimizes the purification of LTA from Lactiplantibacillus plantarum to enhance its anti-biofilm activity against dental pathogens.

## Contribution

A simplified purification method for LTA that retains anti-biofilm activity is proposed.

## Key findings

- LTA-HIC showed higher LTA concentration and better anti-biofilm activity than LTA-Butanol.
- Sodium hydroxide treatment reduced anti-biofilm activity, indicating LTA is the active component.
- LTA-HIC is a viable purification intermediate with retained functionality.

## Abstract

Biofilms formed by oral pathogens play a critical role in the initiation and development of various dental diseases by enhancing resistance to dental medicaments. Previously, we reported the potent anti-biofilm activity of Lactobacillus lipoteichoic acid (LTA), a major cell wall component of Gram-positive bacteria, against various dental pathogens. Nevertheless, the practical application of LTA as an anti-biofilm agent is limited due to its complex, cost- and labor-intensive purification processes. Therefore, to minimize the purification processes required to obtain LTA with anti-biofilm activity, we isolated LTA from Lactiplantibacillus plantarum (Lp.LTA) and its intermediates following each purification step, and compared their anti-biofilm activity against dental pathogens. The Lp.LTA intermediates underwent sequential purification after butanol extraction and hydrophobic-interaction chromatography, and these were designated as LTA-Butanol and LTA-HIC, respectively. The results of Western blot analysis demonstrated that LTA-HIC has a higher concentration of LTA than LTA-Butanol. Although both LTA-Butanol and LTA-HIC dose-dependently inhibited Streptococcus mutans and Porphyromonas gingivalis biofilm formation, the anti-biofilm activity of LTA-HIC was superior to that of LTA-Butanol and comparable to Lp.LTA. Furthermore, sodium hydroxide treatment of LTA-HIC diminished its anti-biofilm activity, suggesting that LTA is a key component responsible for the anti-biofilm capacity of LTA-HIC. Collectively, these results demonstrated that LTA-HIC serves as an intermediate in the LTA purification, retaining its anti-biofilm properties and offering a viable solution to the challenges associated with the LTA purification process.