O'Sullivan L, O'connor E B, Ross R P, Hill C
Teagasc, Dairy Products Research Centre, Moorepark, Fermoy, Co. Cork, Ireland.
J Appl Microbiol. 2006;100(1):135-43. doi: 10.1111/j.1365-2672.2005.02747.x.
A live Lactococcus lactis culture, producing the two-component broad spectrum bacteriocin lacticin 3147, was assessed for ability to inhibit the food pathogen Listeria monocytogenes on the surface of smear-ripened cheese.
In initial experiments, the addition of Listeria to a lacticin 3147-containing fermentate produced with L. lactis DPC4275 (a transconjugant strain derived from L. lactis DPC3147) resulted in at least a 4 log reduction of the pathogen in 30 min. Two separate trials were performed in order to assess the most suitable method for application of the potential protective culture to smear-ripened cheese. In the initial trial, the L. lactis was sprayed onto the surface of the cheese either before or after Listeria was deliberately applied. Application of the culture following Listeria challenge, yielded up to a 1000-fold reduction of the pathogen in contrast to the pretreatment where Listeria numbers were unaffected. In a further trial, three applications of the live lacticin 3147-producing culture was used on a cheese surface containing Listeria. Listeria numbers were found to be up to 100-fold lower than in the cheese treated with L. lactis DPC4268 (control).
While application of the live lacticin 3147 producer did not give complete elimination of the pathogen the results nonetheless demonstrate the potential of the bioprotectant for improving the safety of smear-ripened cheeses and particularly those that contain low level contamination with Listeria.
The application of lacticin 3147 as a live-culture can serve as a bioprotectant for the control of L. monocytogenes on the surface of smear-ripened cheese.
评估一种产双组分广谱细菌素乳酸乳球菌3147的活培养物抑制涂抹成熟干酪表面食源性病原体单增李斯特菌的能力。
在初步实验中，将单增李斯特菌添加到用乳酸乳球菌DPC4275（源自乳酸乳球菌DPC3147的转接合菌株）生产的含乳酸乳球菌3147的发酵产物中，30分钟内病原体数量至少减少4个对数级。进行了两项独立试验，以评估将潜在的保护性培养物应用于涂抹成熟干酪的最合适方法。在初步试验中，在故意接种单增李斯特菌之前或之后，将乳酸乳球菌喷洒在干酪表面。在单增李斯特菌攻击后应用该培养物，与预处理（单增李斯特菌数量未受影响）相比，病原体数量最多减少了1000倍。在进一步的试验中，在含有单增李斯特菌的干酪表面使用产活乳酸乳球菌3147的培养物进行三次应用。发现单增李斯特菌数量比用乳酸乳球菌DPC4268处理的干酪（对照）低多达100倍。
虽然应用产活乳酸乳球菌3147的培养物不能完全消除病原体，但结果仍证明了这种生物保护剂在提高涂抹成熟干酪安全性方面的潜力，特别是对于那些单增李斯特菌污染水平较低的干酪。
将乳酸乳球菌3147作为活培养物应用可作为一种生物保护剂，用于控制涂抹成熟干酪表面的单增李斯特菌。
