Elucidating the mechanisms underlying the action of kenaf seed peptides mixture against gram-positive and gram-negative bacteria and its efficacy in whole milk preservation. (1st May 2023)

• Record Type: Journal Article
• Authors: Arulrajah, Brisha; Qoms, Mohammed S.; Muhialdin, Belal J.; Meor Hussin, Anis Shobirin; Hasan, Hanan; Zarei, Mohammad; Chau, De-Ming; Ramasamy, Rajesh; Saari, Nazamid
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 181(2023)
• Publication Date: 2023-05-01
• Subjects: Milk preservation -- Bactericidal -- Membrane-active peptide -- Molecular docking -- Molecular dynamics simulation; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2023.114757
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: The present study determined the in-situ antibacterial effect of cationic kenaf seed peptides mixture (KSPM) in whole milk and further comprehensively elucidated the mechanisms underlying the bactericidal action against gram-positive and gram-negative bacteria. The application experiments in artificially contaminated milk showed that KSPM at 0.5 and 1 mg/mL displayed a stable and strong bactericidal activity within 1–6 h of treatment and lasted up to two weeks storage at room and refrigeration conditions. The in-vitro mechanistic study showed that the KSPM underwent conformational changes from random coil to α-helix and β-sheet in the membrane-mimetic environment. The KSPM exerted its inhibitory effect in a concentration and time-dependent manner through cell membrane permeabilisation associated with membrane-disrupting effects, which is characterised by the cellular material leakage. The in-silico study revealed that the peptides efficiently interacted with bacterial peptidoglycan via hydrogen bonding, electrostatic interactions and hydrophobic forces. The peptide RALPSEHNK interacted with gram-positive and gram-negative bacterial phospholipid-phosphate head group mainly through electrostatic interaction. The current work indicated that KSPM exerts its bactericidal effect by membrane-targeted mechanism and it would be a promising natural candidate to control bacterial contamination in milk and dairy-based products. Graphical abstract: Image 1 Highlights: KSPM completely inhibited the bacterial population in whole milk model. KSPM did not alter the physicochemical properties of whole milk model. KSPM adopted α-helical and β-sheet structures in a membrane-mimetic environment. KSPM demonstrated a membrane-active action against bacteria.