Synergistic antibacterial effects of postbiotics from Pediococcus acidilactici and Aspergillus fumigatus extracted from large animal feed against Pseudomonas aeruginosa

INTRODUCTION The increasing resistance of pathogenic bacteria to conventional antibiotics has necessitated the search for alternative antimicrobial agents. A postbiotic is any molecule or product resulting from the metabolic activity of living organisms that produces health-giving effects in the host. This study investigated the Synergistic antimicrobial activity of combination of postbiotic metabolites produced by Pediococcus acidilactici and Aspergillus fumigatus extracted from large animal feed against Pseudomonas aeruginosa. MATERIALS AND METHODS This study utilised Pseudomonas aeruginosa as the target pathogen. The Pseudomonas aeruginosa and Pediococcus acidilactici strains were obtained from the Iranian Biological Resource Center (IBRC) in Tehran, Iran. Samples of large animal feed were collected. Aspergillus fumigatus were isolated, and Pediococcus acidilactici metabolites were prepared in liquid culture using Sabro dextrose broth and Mueller-Hinton agar (MHA), respectively, in a shaker incubator. The postbiotic mixture was prepared by combining equal volumes of metabolites from Aspergillus fumigatus and Pediococcus acidilactici. The broth micro dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the postbiotics mixture. Additionally, the disk diffusion and well diffusion methods were employed to evaluate the antimicrobial activity. RESULTS AND DISCUSSION The results demonstrated that the postbiotic metabolites mixture exhibited significant antimicrobial effects, with an MIC of ۱۲۵ μg/mL and an MBC of ۲۵۰ µg/mL. Inhibition zones of ۱۱.۳۳±۰.۵۸ mm, ۱۲.۳۳±۰.۵۸ mm, and ۱۳.۳۳±۰.۵۸ mm were observed in the disk diffusion method at concentrations of ۲۳۰, ۲۵۰, and ۲۷۰ μg/mL, respectively (p-Value ۰.۰۱۶). In the well diffusion method, inhibition zones of ۲۲.۶۷±۰.۵۸ mm, ۲۴.۰۰±۰.۰۰ mm, ۲۴.۶۷±۰.۵۸ mm, and ۲۶.۳۳±۰.۵۸ mm were observed at concentrations of ۲۵۰, ۲۶۰, ۲۷۰, and ۲۸۰ μg/mL, respectively (p-Value <۰.۰۰۱). CONCLUSION These findings suggest that an equal mixture of postbiotic metabolites from Pediococcus acidilactici and Aspergillus fumigatus has potential as an alternative antimicrobial and shows a promising effect against Pseudomonas aeruginosa.

کلیدواژه ها:

Synergistic ، Antimicrobial activity ، Postbiotic ، Probiotic ، Pseudomonas aeruginosa ، Pediococcus acidilactici ، Aspergillus fumigatus