Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, Verona, Italy.
Food Microbiol. 2013 Aug;35(1):27-33. doi: 10.1016/j.fm.2013.02.006. Epub 2013 Mar 7.
The bacteriocin-producing Streptococcus thermophilus strains that can dominate in natural dairy ecosystems, may also enhance safety in products obtained from natural cultures. In this study, we sought to identify bacteriocin production and bacteriocin genes in 75 strains of dairy and plant origin. The strains were tested for antimicrobial activity against pathogens or pathogen models, spoiling bacteria, and lactic acid bacteria associated with dairy products. All strains moderately inhibited Staphylococcus aureus P310, none inhibited Listeria innocua LMG 11387(T) or Clostridium tyrobutyricum LMG 1285(T). In addition, 14 were active against one or more indicators in addition to S. aureus P310. Inhibition of other starter bacteria was more common than the inhibition of unwanted microorganisms. The involvement of a proteinaceous compound was ascertained in all cases. Results suggested that the selection of bacteriocinogenic S. thermophilus strains for use in biopreservation must take into account the effects exerted on other lactic acid bacteria. PCR detection of thermophilin genes proved unreliable in predicting antimicrobial activity. For S. thermophilus PRI36 and PRI45, with relevant inhibitory features, the identity of the bacteriocin genes present in the thermophilin 9 cluster was defined, thus revealing novel variants for this genome region.
能够在自然乳制品生态系统中占主导地位的产细菌素的嗜热链球菌菌株，也可能提高从天然培养物获得的产品的安全性。在本研究中，我们试图鉴定 75 株来自乳制品和植物的菌株的细菌素产生和细菌素基因。这些菌株被测试了对病原体或病原体模型、腐败菌和与乳制品相关的乳酸菌的抗菌活性。所有菌株对金黄色葡萄球菌 P310 均有中等抑制作用，对无害李斯特菌 LMG 11387(T)或酪丁酸梭菌 LMG 1285(T)均无抑制作用。此外，除了 S. aureus P310 外，还有 14 株对一种或多种指示剂有活性。除了抑制不需要的微生物外，对其他起始细菌的抑制更为常见。在所有情况下都确定了一种蛋白质化合物的参与。结果表明，为生物保鲜而选择产细菌素的嗜热链球菌菌株时，必须考虑到其对其他乳酸菌的影响。热稳定素基因的 PCR 检测在预测抗菌活性方面不可靠。对于具有相关抑制特征的 S. thermophilus PRI36 和 PRI45，确定了存在于热稳定素 9 簇中的细菌素基因的身份，从而揭示了该基因组区域的新变体。
