Antibacterial Effects of Nisin and Chive Seed Extract on Staphylococcus aureus

This study aimed to investigate the antibacterial effects of Nisin combined with chive seed extract (CSE) against Staphylococcus aureus and their effect on the quality attributes of strawberries and pasteurized milk during storage. The agar well diffusion assay was employed to assess the antibacterial activity of Nisin and CSE against Staphylococcus aureus ATCC 29213. Additionally, the antibacterial efficacy of Nisin and CSE against S. aureus was further investigated by measuring hemolytic activity, reactive oxygen species (ROS) levels and extracellular polymeric substance (EPS) content. Meanwhile, the effects of Nisin and CSE on the quality of the two food products were further investigated by determining the titratable acidity of pasteurized milk and strawberries during storage, as well as the weight loss and DPPH radical scavenging activity of strawberries and the protein content of pasteurized milk. The results demonstrated that the combination of Nisin and CSE exhibited synergistic antibacterial effect against S. aureus. Notably, ROS levels of S. aureus were significantly reduced by 18.64% and 39.7% in Nisin+CSE group compared to Nisin and CSE groups, respectively (P<0.05). EPS content in S. aureus was remarkably decreased by 17.87% and 32.57% in Nisin+CSE group compared to Nisin and CSE groups, respectively (P<0.05). Furthermore, Nisin combined with CSE effectively delayed spoilage in both pasteurized milk and strawberries during 8-day storage at 25 ℃ and 4 ℃. The combination of Nisin and CSE exhibits a strong inhibitory effect against Staphylococcus aureus, offering a new strategy for the development of natural compound antibacterial agents.