Due to the strong drug resistance of Pseudomonas aeruginosa (P. aeruginosa), the inhibition effects of conventional disinfectants and antibiotics are not obvious. Juglone extracted from discarded walnut husk, as a kind of plant-derived antimicrobial agent, has the advantages of naturalness, high efficiency, and low residue, with a potential role in the inhibition of P. aeruginosa. This study elucidated the inhibitory effect of juglone on the growth of plankton and the formation of P. aeruginosa biofilm. The results showed that juglone (35 μg/mL) had an irreversible inhibitory effect on P. aeruginosa colony formation (about 10⁷ CFU/mL). The integrity and permeability of the cell membrane were effectively destroyed, accompanied by disorder of the membrane permeability, mass leakage of the cytoplasm, and ATP consumption. Further studies manifested that juglone could induce the abnormal accumulation of ROS in cells and block the formation of the cell membrane. In addition, RT-qPCR showed that juglone could effectively block the expression of five virulence genes and two genes involved in the production of extracellular polymers, thereby reducing the toxicity and infection of P. aeruginosa and preventing the production of extracellular polymers. This study can provide support for the innovation of antibacterial technology toward P. aeruginosa in food.

中文翻译：

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Juglone 通过细胞膜损伤、生物膜阻塞和基因表达抑制灭活铜绿假单胞菌

由于铜绿假单胞菌（P. aeruginosa）的耐药性很强，常规消毒剂和抗生素的抑制作用不明显。从废弃核桃壳中提取的胡桃酮作为一种植物源性抗菌剂，具有天然、高效、低残留等优点，对绿脓杆菌具有潜在的抑制作用。本研究阐明了胡桃苷对浮游生物生长和铜绿假单胞菌生物膜形成的抑制作用。结果表明胡桃酮（35 μg/mL）对铜绿假单胞菌菌落形成（约10 ⁷CFU/毫升）。细胞膜的完整性和通透性被有效破坏，伴随着细胞膜通透性紊乱、细胞质大量渗漏和ATP消耗。进一步研究表明，胡桃苷可诱导细胞内ROS异常积累，阻断细胞膜的形成。此外，RT-qPCR显示胡桃苷能有效阻断5个毒力基因和2个参与胞外多聚体产生的基因的表达，从而降低铜绿假单胞菌的毒性和感染，阻止胞外多聚体的产生。本研究可为食品中铜绿假单胞菌抗菌技术的创新提供支持。