Characteristic of Co-Culture Biofilm Formed by Lactobacillus plantarum and Pediococcus acidilactici, and Antagonistic Effects of This Biofilm on Pathogen Growth

Recent studies in lactic acid bacteria (LAB) biofilm formation have reported that the functional properties of LAB are associated with biofilm formation. In this study, Pediococcus acidilactici and Lactobacillus plantarum showed the ability to form a biofilm on a solid surface under static conditions. The morphology of LAB on MRS-CR agar showed that both P. acidilactici and L. plantarum could produce exopolysaccharide (EPS) on the cell surface which mainly contributed to forming the biofilm o f single and co-culture strains on solid surfaces. Under the flow condition, cell motility played an important role in supporting the cell to overcome the repulsive force to reach and interact with the surface. As a result, the L. plantarum and co-culture cells with higher motility caused a noticeably thicker biofilm on the glass surface compared to the P. acidilactici strain. Moreover, the antagonistic activity assay showed that co-culture biofilm formation improved the antagonistic effects of LAB against Pseudomonas aeruginosa and Salmonella typhimurium compared to those in planktonic culture. It suggested that co-culture biofilm could be an effective model to apply useful LAB as potential probiotics and to control pathogen in food chain, especially under the flow condition.