Bactericidal and non‐cytotoxic activity of bacteriocin produced by Lacticaseibacillus paracasei F9‐02 and evaluation of its tolerance to various physico‐chemical conditions

• Published in: Environmental microbiology 2023-12, Vol.25 (12), p.2882-2896
• Main Authors: Duraisamy, Senbagam, Sathyan, Aswathy, Balakrishnan, Senthilkumar, Subramani, Prabhu, Prahalathan, Chidhambaram, Kumarasamy, Anbarasu
• Format: Article
• Language: English
• Subjects: Analytical methods; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antimicrobial activity; Antimicrobial agents; Bacteria; Bacteriocins; Bacteriocins - pharmacology; Breast; Calcium chloride; Catalase; Copper chloride; Cytotoxicity; Disease resistance; Drug resistance; Electrophoresis; Enterococcus; Enzymes; Faeces; Feces; Fourier transforms; Gel electrophoresis; Gels; Humans; Hydrogen-Ion Concentration; Infant; Infants; Klebsiella; Klebsiella pneumoniae; Lactic acid; Lactic acid bacteria; Lacticaseibacillus paracasei; Lactobacillus; Lysozyme; Metal ions; Metals; Methicillin; Methicillin-Resistant Staphylococcus aureus; Minimum inhibitory concentration; Molecular weight; Pathogens; Polyacrylamide; Pseudomonas aeruginosa; Salmonella Typhi; Shigella flexneri; Sodium; Sodium chloride; Sodium Dodecyl Sulfate; Sodium lauryl sulfate; Spectroscopy, Fourier Transform Infrared; Staphylococcus aureus; Sulfates; Vancomycin; Zinc sulfate
• ISSN: 1462-2912; 1462-2920
• DOI: 10.1111/1462-2920.16327

This study aims to explore novel lactic acid bacteria (LAB) from breast‐fed infants' faeces towards characterizing their antimicrobial compound, bacteriocin. The LAB, Lacticaseibacillus paracasei F9‐02 showed strong antimicrobial activity against clinical pathogens. Their proteinaceous nature was confirmed as the activity was completely abolished when treated with proteinaceous enzymes and retained during neutral pH and catalase treatment. The purified bacteriocin showed antimicrobial activity at the minimum inhibitory concentration (MIC) value of 7.56 μg/ml against vancomycin‐resistant Enterococcus sp. [vancomycin‐resistant enterococcal (VRE)], and methicillin‐resistant Staphylococcus aureus (MRSA), 15.13 μg/ml against Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica subsp. enterica serotype typhi and 30.25 μg/ml against Shigella flexneri. Present study also proved the bactericidal, non‐cytotoxic and non‐hemolytic nature of bacteriocin. Additionally, bacteriocin retained their stability under various physico‐chemical conditions, broad range of pH (2–10), temperature (40–121°C), enzymes (amylase, lipase and lysozyme), surfactants [Tween‐20, 80, 100 and sodium dodecyl sulfate (SDS)], metal ions (CaCl2, FeSO4, ZnSO4, MgSO4, MnSO4, CuCl2) and NaCl (2%–8%). The molecular weight of bacteriocin (~28 kDa) was determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), functional and active groups were assessed by Fourier Transform‐Infrared (FT‐IR). To our knowledge, this is the first study reporting L. paracasei from breast‐fed infants' faeces and assessing their antimicrobial compound, bacteriocin. The study results furnish the essential features to confirm the therapeutic potential of L. paracasei F9‐02 bacteriocin.