大连工业大学食品学院夏效东教授团队在Food Control发表题目为“Inhibition of Shewanella putrefaciens biofilm by laurel essential oil and its potential mechanisms”研究论文（月桂精油对腐败希瓦氏菌生物膜的抑制及其潜在机制）。摘要： 腐败希瓦氏菌（S. putrefaciens）是水产品中的主要腐败菌，具有很强的形成生物膜的能力，这导致其在食品系统中的污染和持久性。本研究旨在通过表型分析研究月桂精油（LEO）对腐败希瓦氏菌生物膜形成的影响，并使用 RNA 测序（RNA-seq）分析探索其潜在机制。LEO 显著减少了实验室培养基和食品汤（牡蛎汁和鲈鱼汁）以及虾表面和不同食品接触表面（304 型不锈钢、玻璃和食品级硅胶）中的生物膜形成。此外，LEO 还抑制细菌运动，降低细胞外聚合物 (EPS) 含量，并改变生物膜结构。此外，RNA-seq 分析还发现了 229 个差异表达基因 (DEG)，这些基因参与转录调控、多药外排泵转运蛋白、核糖体、细胞运动、环境因素和双组分系统。总之，这些发现将 LEO 确定为 S. putrefaciens 的潜在天然抗生物膜剂，并为其抗生物膜机制提供了见解。研究结果：3.1. LEO 对腐败链球菌的 MIC 和 SICFig. 1. A: Growth curve of S. putrefaciens treated by LEO; B: Biofilm formation of S. putrefaciens in LB broth; C: The metabolic activity of S. putrefaciens biofilm cells; D: FESEM images of S. putrefaciens biofilm treated with LEO; E: Fluorescence microscopy images of S. putrefaciens biofilm treated with LEO.3.3. LEO 减少了不同食物汁液和食物接触表面上的 S. putrefaciens 生物膜Fig. 2. Biofilm formation of S. putrefaciens in oyster juice (A) and sea bass juice (B); The impacts of LEO on the adhesion of S. putrefaciens to stainless steel (C), glass (D), silicone (E) and shrimp surfaces (F).3.4. LEO 降低了 S. putrefaciens 生物膜中的 EPS 含量Fig. 3. LEO reduced exopolysaccharides (A), eDNA (B) and extracellular proteins contents (C) of S. putrefaciens biofilm cells; LEO impaired the surface hydrophobicity (D) and auto-aggregation (E) of S. putrefaciens.3.6. LEO 减弱了 S. putrefaciens 的运动能力Fig. 4. The diameters of swimming (A) and swarming motility (B); the images of swimming (C) and swarming motility (D).3.7. DEG分析Fig. 5. Volcano map of DEGs for LEO-treated sample vs control (A); The number of down-regulated and up-regulated genes of LEO-treated sample vs control (B); Co-expression Venn diagram (C) (Different samples were represented by different colors. The overlapping area represented the number of expressed genes shared by different samples, and the non-overlapping area represented the number of unique expressed genes between different samples); Gene expression violin plot (D) (The width of each violin graphic reflected the number of points at that expression level).3.8. GO、COG和KEGG富集分析Fig. 6. GO analysis of DEGs to LEO-treated sample vs control (A) (The horizontal axis represented the functional classification, and the vertical axis represented the number of genes within the classification (right) and its percentage of the total number of annotated genes (left). Different colors represented different categories. Light color represented DEGs, and dark color represented all genes.); Classification of the DEGs according to the COG (B); The main categories of DEGs in KEGG enrichment (C); The enriched KEGG pathways (D). (The size and color of the dot represented the number of DEGs and the range of q value).原文链接：https://doi.org/10.1016/j.foodcont.2024.110776
