College of Ocean Food and Biological Engineering, Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Jimei University, 43 Yindou Road, Xiamen, Fujian 361021, China.
Department of Biology and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong 515063, China.
Int J Food Microbiol. 2022 Jul 16;373:109713. doi: 10.1016/j.ijfoodmicro.2022.109713. Epub 2022 May 9.
The increasing demand for ready-to-eat fresh foods requires the use of non-thermal sterilization, hence, the application of antimicrobial peptides (AMPs) combined with ultrasound could serve as a novel food preservation method to prevent foodborne diseases. In this study, in silico tools were used to predict and screen potential AMPs from the antimicrobial amino acid sequence of myosin heavy chain of Larimichthys crocea. A novel AMP, designated as LCMHC, had strong antibacterial activity against Staphylococcus aureus when combined with low-intensity ultrasound treatment. The minimal inhibitory concentration (MIC) of LCMHC was 125 μg/mL when used alone but 31.25 μg/mL when combined with 0.3 W/cm ultrasound treatment. Structural analysis using circular dichroism (CD) revealed that peptide LCMHC has α-helical structure, which had slightly untwisting effect with increasing ultrasonic intensity. Transmission electron microscopy and permeability analysis of bacteria cell membrane showed that low-intensity ultrasound combined with peptide LCMHC could greatly improve the cell membrane permeability of S. aureus. Moreover, low intensity-ultrasound could assist the entry of more peptide LCMHC into bacterial cells to bind DNA. The findings here provide new insight into the potential application of peptide LCMHC combined with low-intensity ultrasound in the food industry.
对即食新鲜食品的需求不断增加，需要使用非热灭菌方法，因此，将抗菌肽 (AMP) 与超声结合使用可以作为一种新的食品保鲜方法，以预防食源性疾病。在这项研究中，使用计算机模拟工具从大黄鱼肌球蛋白重链的抗菌氨基酸序列中预测和筛选潜在的 AMP。一种新型 AMP，命名为 LCMHC，与低强度超声处理联合使用时对金黄色葡萄球菌具有很强的抗菌活性。单独使用时，LCMHC 的最小抑菌浓度 (MIC) 为 125 μg/mL，但与 0.3 W/cm 的超声处理联合使用时，MIC 为 31.25 μg/mL。使用圆二色性 (CD) 进行结构分析表明，肽 LCMHC 具有 α-螺旋结构，随着超声强度的增加，其螺旋结构略有扭曲。细菌细胞膜的透射电子显微镜和通透性分析表明，低强度超声联合肽 LCMHC 可以大大提高金黄色葡萄球菌的细胞膜通透性。此外，低强度超声可以帮助更多的肽 LCMHC 进入细菌细胞与 DNA 结合。这些发现为肽 LCMHC 与低强度超声联合应用于食品工业提供了新的见解。
