Department of Food Microbiology, CSIR-Central Food Technological Research Institute, Mysore, Karnataka, India.
Curr Microbiol. 2012 Aug;65(2):162-9. doi: 10.1007/s00284-012-0138-z. Epub 2012 May 13.
Food borne diseases have a major impact on public health whose epidemiology is rapidly changing. The whole cells of pathogens involved or their toxins/metabolites affect the human health apart from spoiling sensory properties of the food products finally affecting the food industry as well as consumer health. With pathogens developing mechanisms of antibiotic resistance, there has been an increased need to replace antibiotics as well as chemical additives with naturally occurring bacteriocins. Bacteriocins are known to act mainly against Gram-positive pathogens and with little or no effect towards Gram-negative enteric bacteria. In the present study, combination effect of lipase and bacteriocin produced by Enterococcus faecium NCIM5363, a highly lipolytic lactic acid bacterium against various food pathogens was assessed. The lipase in combination with enterocin exhibited a lethal effect against Gram-negative pathogens. Scanning electron microscopy studies carried out to ascertain the constitutive mode of action of lipase and enterocin revealed that the lipase degrades the cell wall of Gram-negative bacteria and creates a pore through which enterocin enters thereby resulting in cell death. The novelty of this work is the fact that this is the first report revealing the synergistic effect of lipase with enterocin against Gram-negative bacteria.
食源性疾病对公共卫生有重大影响，其流行病学正在迅速变化。病原体的整个细胞或其毒素/代谢物除了最终影响食品工业和消费者健康外，还会影响食品的感官特性，从而影响人类健康。随着病原体对抗生素产生耐药性的机制的发展，人们越来越需要用天然存在的细菌素来替代抗生素和化学添加剂。细菌素已知主要针对革兰氏阳性病原体起作用，对革兰氏阴性肠道细菌几乎没有影响或没有影响。在本研究中，评估了脂肪酶和肠球菌素的组合效应，肠球菌素由高度脂解的乳酸菌粪肠球菌 NCIM5363 产生，针对各种食品病原体。脂肪酶与肠球菌素联合使用对革兰氏阴性病原体表现出致命作用。进行扫描电子显微镜研究以确定脂肪酶和肠球菌素的组成作用模式，结果表明脂肪酶降解革兰氏阴性细菌的细胞壁并产生一个孔，肠球菌素通过该孔进入，从而导致细胞死亡。这项工作的新颖之处在于，这是第一个揭示脂肪酶与肠球菌素对革兰氏阴性细菌协同作用的报告。
