Fahimirad Shohreh, Abtahi Hamid, Razavi Seyed Hadi, Alizadeh Houshang, Ghorbanpour Mansour
Agriculture and Natural Resources Biotechnology Department, University of Tehran, Karaj 31587-11167, Iran.
Molecular and Medicine Research Center, Arak University of Medical Sciences, Arak, Molecular and Medicine Research Center, Arak University of Medical Sciences, Arak 38181-76941, Iran.
Molecules. 2017 May 31;22(6):822. doi: 10.3390/molecules22060822.
Accelerating emergence of antimicrobial resistance among food pathogens and consumers' increasing demands for preservative-free foods are two contemporary challenging aspects within the food industry. Antimicrobial packaging and the use of natural preservatives are promising solutions. In the present study, we used -casein-one of the primary self-assembly proteins in milk with a high polymeric film production capability-as a fusion partner for the recombinant expression of E 50-52 antimicrobial peptide in . The construct was transformed to , and protein expression was induced under optimized conditions. Purified protein obtained from nickel affinity chromatography was refolded under optimized dialysis circumstances and concentrated to 1600 µg/mL fusion protein by ultrafiltration. Antimicrobial activities of recombinant BCN-E 50-52 performed against , , , , , and . Subsequently, the synergistic effects of BCN-E 50-52 and thymol were assayed. Results of checkerboard tests showed strong synergistic activity between two compounds. Time-kill and growth kinetic studies indicated a sharp reduction of cell viability during the first period of exposure, and SEM (scanning electron microscope) results validated the severe destructive effects of BCN E 50-52 and thymol in combination on bacterial cells.
食品病原体中抗菌药物耐药性的加速出现以及消费者对无防腐剂食品日益增长的需求,是食品行业当前面临的两个具有挑战性的方面。抗菌包装和天然防腐剂的使用是很有前景的解决方案。在本研究中,我们使用了β-酪蛋白(牛奶中主要的自组装蛋白之一,具有高聚合物薄膜生产能力)作为融合伙伴,用于在大肠杆菌中重组表达E 50-52抗菌肽。将构建体转化到大肠杆菌中,并在优化条件下诱导蛋白质表达。通过镍亲和层析获得的纯化蛋白在优化的透析条件下复性,并通过超滤浓缩至1,600 μg/mL融合蛋白。对重组BCN-E 50-52针对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、单核细胞增生李斯特菌、鼠伤寒沙门氏菌和肠炎沙门氏菌进行抗菌活性测试。随后,测定了BCN-E 50-52和百里香酚的协同作用。棋盘格试验结果表明两种化合物之间具有很强的协同活性。时间杀灭和生长动力学研究表明,在暴露的第一阶段细胞活力急剧下降,扫描电子显微镜(SEM)结果证实了BCN E 50-52和百里香酚联合使用对细菌细胞具有严重的破坏作用。