Potential Probiotic Lactic Acid Bacteria with Anti-Penicillium expansum Activity from Different Species of Tunisian Edible Snails

• Published in: Probiotics and antimicrobial proteins 2023-02, Vol.15 (1), p.82-106
• Main Authors: Rabaoui, Ghada, Sánchez-Juanes, Fernando, Tebini, Mohamed, Naghmouchi, Karim, Bellido, Juan Luis Muñoz, Ben-Mahrez, Kamel, Réjiba, Samia
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Applied Microbiology; Bacteria; Bile salts; Biofilms; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Chloramphenicol; Chloroform; Gastrointestinal tract; Gentamicin; Gram-Negative Bacteria; Gram-Positive Bacteria; Hydrolase; Ions; Lactic acid bacteria; Lactobacillales; Lysozyme; Mass spectroscopy; Microbiology; Mollusks; Nutrition; Penicillium expansum; pH effects; Probiotics; Probiotics - pharmacology; Protein Science; Strains (organisms); Streptomycin; Sulfamethoxazole; Trimethoprim; Trimethoprim-sulfamethoxazole
• ISSN: 1867-1306; 1867-1314
• DOI: 10.1007/s12602-021-09882-5

This study aimed to isolate lactic acid bacteria (LAB) from the digestive tract, meat and slime of edible snails ( Helix lucorum , Helix aspersa and Eobania vermiculata ) and investigate their antagonistic activity against Penicillium expansum . They were then characterized for their probiotic potential. Among 900 bacterial isolates, 47 LAB exhibiting anti- P. expansum activity were identified through matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as Levilactobacillus brevis (25), Lactococcus lactis (3), Enterococcus faecium (12), Enterococcus faecalis (4), Enterococcus casseliflavus (1), and Enterococcus mundtii (2). Sixty-two percent of the strains were tolerant to 100 mg/L of lysozyme. Seventy two percent of the isolates were able to survive at pH 3 and most of them tolerate 2.5% bile salt concentration. Moreover, 23% of the strains displayed bile salt hydrolase activity. Interestingly, all strains were biofilm strong producers. However, their auto- and co-aggregation properties were time and pH dependent with high aggregative potentiality at pH 4.5 after 24 h. Remarkably, 48.94% of the strains showed high affinity to chloroform. The safety assessment revealed that the 47 LAB had no hemolytic activity and 64% of them lacked mucin degradation activity. All isolated strains were susceptible to gentamycin, streptomycin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. Overall, 43 LAB strains showed inhibitory activity against a broad spectrum of pathogenic Gram-positive and gram-negative bacteria, fungi, and yeast. Our findings suggest that L. brevis (EVM12 and EVM14) and Ent. faecium HAS34 strains could be potential candidates for probiotics with interesting antibacterial and anti- P. expansum activities.