Antimicrobial and Antibiofilm Effect of Bacteriocin-Producing Pediococcus inopinatus K35 Isolated from Kimchi against Multidrug-Resistant Pseudomonas aeruginosa

Recently, the emergence of multidrug-resistant bacteria due to the misuse of antibiotics has attracted attention as a global public health problem. Many studies have found that fermented foods are good sources of probiotics that are beneficial to the human immune system. Therefore, in this study, we tried to find a substance for the safe alternative treatment of multidrug-resistant bacterial infection in kimchi, a traditional fermented food from Korea.Antimicrobial activity and antibiofilm activity were assessed against multidrug-resistant (MDR) Pseudomonas aeruginosa using cell-free supernatants of lactic acid bacteria (LAB) isolated from kimchi. Then, UPLC-QTOF-MS analysis was performed to detect the substances responsible for the antimicrobial effect.The cell-free supernatant (CFS) of strain K35 isolated from kimchi effectively inhibited the growth of MDR P. aeruginosa. Similarly, CFS from strain K35 combined with P. aeruginosa co-cultures produced significant inhibition of biofilm formation upon testing. On the basis of 16s rRNA gene sequence similarity, strain K35 was identified as Pediococcus inopinatus. As a result of UPLC-QTOF-MS analysis of the CFS of P. inopinatus K35, curacin A and pediocin A were detected.As a result of this study, it was confirmed that P. inopinatus isolated from kimchi significantly reduced MDR P. aeruginosa growth and biofilm formation. Therefore, kimchi may emerge as a potential source of bacteria able to help manage diseases associated with antibiotic-resistant infections.