Antimicrobial activity and mechanism of α-copaene against foodborne pathogenic bacteria and its application in beef soup
Shangyan Chen, Hao Zheng, Sheng‐Ping Yang, Yonggang Qi, Wei Li, Sini Kang, Han Hu, Qiang Hua, Yongkang Wu, Zhijie Liu
Abstract
Excessive use of traditional food preservatives has raised concerns about their adverse effects. α-Copaene is a natural terpene compound with excellent biological activity; however, the antibacterial activity and mechanism of α-copaene are unclear. Therefore, this study aimed to explore the antibacterial activity and mechanism of action of α-copaene against four common foodborne pathogens: Staphylococcus aureus, Escherichia coli, Bacillus cereus, and Shigella bogdii. α-Copaene inhibited bacterial growth with a minimum inhibitory concentration of 0.5–1 μL/mL and a minimum bactericidal concentration of 2–4 μL/mL. Scanning electron microscopy and flow cytometry showed morphological changes and damage to the cell membrane in cells treated with α-copaene. Confocal microscopy and cell content leakage further confirmed cell membrane damage and increased permeability caused by α-copaene treatment. α-Copaene suppressed biofilm formation by decreasing the hydrophobicity of the cell surface. Furthermore, the hemolytic activity and cytotoxicity assays showed that α-copaene had good biosafety. In conclusion, 4 μL/mL of α-copaene inhibited the growth of S. aureus, E. coli, B. cereus, and Sh. bogdii in beef soup. These results provide evidence of the antibacterial activity and mechanism of α-copaene and pave the way for developing α-copaene as a novel food preservative.