Wang Shichun, Song Xiaodong, Zheng Xuan, Cheng Congyang, Jin Junhua, Xie Yuanhong, Zhang Hongxing
Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Agricultural Product Detection and Control of Spoilage Organisms and Pesticide Residue, College of Food Science and Engineering, Beijing University of Agriculture, Beijing, China.
Key Laboratory of Dairy Quality Digital Intelligence Monitoring Technology, State Administration for Market Regulation, Inner Mongolia Mengniu Dairy (Group) Co., Ltd., Hohhot, China.
Front Microbiol. 2025 Jun 20;16:1606567. doi: 10.3389/fmicb.2025.1606567. eCollection 2025.
Plantaricin BM-1 is a class IIa bacteriocin active against . However, the mode of action of class IIa bacteriocins against gram-negative bacteria remains unclear. In this study, the regulatory role of sigma factor FliA (σ) in the antibacterial mechanism of plantaricin BM-1 against K-12 BW25113 is evaluated.
The -complemented strain of JW1907, namely ReJW1907, was constructed through λ-Red homologous recombination. The effects of plantaricin BM-1 on growth, cell morphology, and membrane integrity were investigated using growth curves, electron microscopy, and flow cytometry. The biofilm formation ability of was evaluated using crystal violet staining and confocal laser scanning microscopy. Transcriptomic analysis was performed to screen for differentially expressed genes (DEGs).
The inhibition rate (I%) of plantaricin BM-1 (3.75 mg/mL) against JW1907 (89.22 ± 1.13%) at the 8th h of culture was significantly higher than that of BW25113 (70.36 ± 6.30%) and ReJW1907 (74.75 ± 4.99%). The biofilm biomass produced by BW25113 (OD = 0.343 ± 0.056) was significantly reduced to 0.227 ± 0.04 after deletion, and was recovered to its original level (0.358 ± 0.027) after complement. A total of 205 DEGs were identified between BW25113 and JW1907. Among these, four DEGs (,, , and ) were enriched in the biofilm formation pathway. Further analysis revealed eight up-regulated DEGs (), which were significantly enriched in the LuxS/AI-2 quorum sensing (QS) system. After the deletion of any gene from , the I% of plantaricin BM-1 against BW25113 (70.77 ± 7.01%) was significantly increased to 80.68-90.06%, with its biofilm production (0.254 ± 0.014) reduced to 0.135-0.188. In conclusion, FliA modulates biofilm formation through the LuxS/AI-2 QS system, thereby regulating the antibacterial activity of plantaricin BM-1. Overall, these findings improve our understanding of the bacteriostatic mechanism of class IIa bacteriocins against gram-negative bacteria.
植物乳杆菌素BM - 1是一种对……具有活性的IIa类细菌素。然而，IIa类细菌素对革兰氏阴性菌的作用模式仍不清楚。在本研究中，评估了σ因子FliA（σ）在植物乳杆菌素BM - 1对K - 12 BW25113的抗菌机制中的调节作用。
通过λ - Red同源重组构建了JW1907的 - 互补菌株，即ReJW1907。使用生长曲线、电子显微镜和流式细胞术研究了植物乳杆菌素BM - 1对……生长、细胞形态和膜完整性的影响。使用结晶紫染色和共聚焦激光扫描显微镜评估了……的生物膜形成能力。进行转录组分析以筛选差异表达基因（DEG）。
在培养第8小时，植物乳杆菌素BM - 1（3.75 mg/mL）对JW1907的抑制率（I%）（89.22 ± 1.13%）显著高于对BW25113（70.36 ± 6.30%）和ReJW1907（74.75 ± 4.99%）的抑制率。BW25113产生的生物膜生物量（OD = 0.343 ± 0.056）在……缺失后显著降低至0.227 ± 0.04，并在……互补后恢复到原始水平（0.358 ± 0.027）。在BW25113和JW1907之间共鉴定出205个DEG。其中，四个DEG（……）在生物膜形成途径中富集。进一步分析揭示了八个上调的DEG（……），它们在LuxS/AI - 2群体感应（QS）系统中显著富集。从……中删除任何一个基因后，植物乳杆菌素BM - 1对BW25113的I%（70.77 ± 7.01%）显著增加至80.68 - 90.06%，其生物膜产量（0.254 ± 0.014）降低至0.135 - 0.188。总之，FliA通过LuxS/AI - 2 QS系统调节生物膜形成，从而调节植物乳杆菌素BM - 1的抗菌活性。总体而言，这些发现增进了我们对IIa类细菌素对革兰氏阴性菌抑菌机制的理解。
