Microbiology and Fermentation Technology Department, CSIR-Central Food Technological Research Institute, Mysore, 570 020, India.
Microb Pathog. 2019 Mar;128:139-146. doi: 10.1016/j.micpath.2018.12.044. Epub 2018 Dec 27.
Probiotic bacteria with antibacterial activity is of desirable trait since they can check the growth of pathogenic bacteria besides exhibiting health benefits to host. Aim of this study was to characterize Bacillus licheniformis MCC 2512 (MCC 2512), a potential probiotic culture for its ability to produce subtilin-like antibiotics. The anti-microbial compound produced by MCC 2512 was identified and characterized using subtilin-specific cell reporter, Bacillus subtilis 168:BS2 (BS2). Induction of β-gal by the test culture suggested the ability of B. licheniformis to produce subtilin-like lantibiotic. Subsequently, DNA sequencing of major lanS-operon was carried out, wherein sequencing results showed that lan cluster of MCC 2512 resembles entianin (etn) type. Upon lan-S disruption, the bacterial culture lost antimicrobial activity as well as ability to induce β-gal with BS2 reporter. High amount of succinylated form of antibiotics produced by wild type and un-succinylated form by engineered strain of B. subtilis 15029p clearly indicates that MCC 2512 is indeed an inter-specific subtilin-like (named as sublichenin) lantibiotic producer. Partially concentrated sublichenin preparation exhibited strong antibacterial activity against food-borne pathogens and antibiotic resistant (AR) lactic acid bacteria (LAB) with a minimum inhibitory concentration in the range of 6-10 and 0.5-1.5 μg/ml, respectively. Production of lantibiotic, sublichenin by a probiotic bacterium of B. licheniformis MCC 2512 and its antibacterial activity against food associated AR LAB is a new information reported in this study.
具有抗菌活性的益生菌是理想的特性，因为它们除了对宿主表现出健康益处外，还可以抑制病原菌的生长。本研究的目的是表征地衣芽孢杆菌 MCC 2512（MCC 2512），这是一种有潜力的益生菌培养物，因为它能够产生类似于枯草菌素的抗生素。使用枯草芽孢杆菌 168：BS2（BS2）的枯草菌素特异性细胞报告物来鉴定和表征 MCC 2512 产生的抗微生物化合物。测试培养物诱导的β-半乳糖苷酶表明地衣芽孢杆菌能够产生类似于枯草菌素的类细菌素。随后，对主要 lanS 操纵子进行 DNA 测序，测序结果表明 MCC 2512 的 lan 簇类似于恩坦宁（etn）型。在 lan-S 失活后，细菌培养物失去了抗菌活性以及用 BS2 报告物诱导β-半乳糖苷酶的能力。野生型产生的大量琥珀酰化形式的抗生素和枯草芽孢杆菌 15029p 的工程菌株产生的非琥珀酰化形式的抗生素清楚地表明，MCC 2512 确实是一种种间枯草菌素样（命名为 sublichenin）类细菌素产生菌。部分浓缩的 sublichenin 制剂对食源性病原体和抗生素耐药（AR）乳酸菌表现出很强的抗菌活性，最低抑菌浓度范围分别为 6-10 和 0.5-1.5μg/ml。地衣芽孢杆菌 MCC 2512 的益生菌产生类细菌素 sublichenin 及其对食品相关 AR LAB 的抗菌活性是本研究中报道的新信息。
