Bacteriocins as interventions for food safety

消费者对新鲜、加工程度最低的方便食品的需求导致冷藏即食食品的供应大幅增加。目前，冷藏是可能污染这些产品的食源性病原体生长的唯一障碍。乳酸菌（LAB）产生抗菌肽，称为细菌素，其抑制某些致病菌的生长。有必要进一步发展灵敏的分析技术，用于检测这些化合物。 我们开发了一种灵敏的方法，使用基质辅助激光解吸/电离飞行时间质谱仪检测细菌素，这种方法被用来确定乳酸链球菌素的命运，被批准用于食品中的细菌素。 然而，我们未能在食物中检测到其他细菌素的产生。 需要进一步的研究来提高检测食品中产生的细菌素的分析技术的灵敏度和特异性。 最近的研究表明，在模型系统中存在一种以上的细菌素可以显着增加对食源性病原体的抑制活性。 然而，单一生物体中多种细菌素的产生并没有导致抗微生物活性的增加。这将是必须克服的，如果我们要优化细菌素的生产在LAB.本研究计划的目标是：1）优化方法检测食品中的细菌素;和2）开发基于遗传的策略，以提高生产的多种细菌素在LAB。 这项研究的成功结果将为食品工业提供有效的生物防腐剂，用于最低限度加工的肉类，并将提供检测食品中细菌素的方法。进一步了解乳酸菌和细菌素在微生物生态学中的作用，将大大提高它们作为提高我们食品供应安全的障碍的应用。

Consumer demand for fresh, minimally processed, convenient food products has resulted in a tremendous increase in the availability of refrigerated, ready-to-eat foods. Currently, refrigeration is the only hurdle to the growth of foodborne pathogens that can contaminate these products. Lactic acid bacteria (LAB) produce antibacterial peptides, known as bacteriocins, which inhibit the growth of some pathogenic bacteria. There is need for further development of sensitive analytical techniques for detection of these compounds.  We developed a sensitive method for detection of bacteriocins using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer and this method was used to determine the fate of nisin, a bacteriocin that is approved for use in foods.  However, we have not been able to detect the production of other bacteriocins in foods.  Further research is required to improve the sensitivity and specificity of analytical techniques for detection of bacteriocins produced in foods.  Recent research has shown that the presence of more than one bacteriocin in a model system can dramatically increase the inhibitory activity against foodborne pathogens.  However, production of multiple bacteriocins in a single organism has not resulted in increased antimicrobial activity. This will have to be overcome if we are to optimize bacteriocin production in LAB.The objectives of this research program are to: 1) optimize methods for detection of bacteriocins in foods; and to 2) develop genetic-based strategies to improve production of multiple bacteriocins in LAB.  The successful outcome of this research will provide the food industry with effective biopreservatives for minimally processed meats and will provide assays for detection of bacteriocins in foods. Further understanding of the role of lactic acid bacteria and bacteriocins in microbial ecology will greatly enhance their application as hurdles to enhance the safety of our food supply.