Evaluation of the antifungal and antibiofilm activity of postbiotics derived from Lactobacillus spp. on Penicillium expansoum in vitro and in food model.

Food degradation made by mycotoxigenic molds represents a significant challenge too food security. Postbiotics are associated with soluble compounds liberated by living bacterial cells or their construction release after lysis, and these metabolites offer the host biological action and specific physiological benefits. In this work, the postbiotics from tree strains of Lactobacillus spp. (Limosilactobacillus reuteri ATCC 367, Lacticaseibacillus casei431and Levilactobacillus brevisATCC) were lyophilized, filtered, and tested to evaluate the antimicrobial and anti-biofilm activity in vitro and milk against P. expansoum. Also, to assess the antioxidant efficacy and the free radical scavenging possibility of the postbiotic, DPPH, and ABTS + methods were used. Antimicrobial activity and biofilm removal activity of postbiotics depended on the Lactobacillus strains used. The minimum inhibitory concentration (MIC) of the prepared postbiotic was determined to be 70ug/ml. The lowest minimum effective concentration (MEC) of postbiotics were significantly differed, in the food matrix, and a low MEC index (100 mg/ml) was detected for postbiotic of L. brevis. Postbiotics derived from L. brevis showed the highest antimicrobial activity compared to L. casei and L. reuteri. The postbiotic extracted from Lactobacillus strain may have functional properties (potential antimicrobial and anti-biofilm) in vitro and food models.