Two strains of 64 endophytic bacteria, Bacillus cereus Si‐Ps1 and Pseudomonas azotoformans La‐Pot3‐3, isolated from Citrus sinensis and C. sinensis var. Thomson's leaves, respectively, reduced N‐acyl homoserine‐based quorum sensing in bioindicator strain Pseudomonas syringae pv. syringae (Pss) B728a and the biofilm production and swarming motility of field isolate Pss 3289. A homolog of aiiA gene encoding an AHL‐lactonase was found in B. cereus (Si‐Ps1), suggesting that this isolate can degrade the quorum‐sensing signal molecules of Pss 3289. The crude extract of endophytic bacterium, B. cereus (Si‐Ps1), inhibited Pss 3289 biofilm formation after 48 and 96 h by 55% and 58%, respectively. Similar reductions in biofilm formation were conferred by crude extracts of P. azotoformans (La‐Pot3‐3). Correspondingly, the number of planktonic cells in cultures treated with these extracts was higher than in control cultures, indicating a direct effect on biofilm formation and not on cell growth. In greenhouse assays, the virulence of Pss 3289 to different citrus cultivars was decreased when coinoculated with these endophytic bacteria.

中文翻译：

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群体淬灭内生细菌抑制由丁香假单胞菌引起的疾病。柑橘品种中的丁香

两株 64 种内生细菌，蜡样芽孢杆菌 Si-Ps1 和固氮假单胞菌 La-Pot3-3，从 Citrus sinensis 和 C. sinensis var. 中分离。Thomson 的叶子分别降低了生物指示菌株​​ Pseudomonas syringae pv 中基于 N-酰基高丝氨酸的群体感应。syringae (Pss) B728a 和野外分离物 Pss 3289 的生物膜产生和蜂群运动。在蜡状芽孢杆菌 (Si-Ps1) 中发现了编码 AHL-内酯酶的 aiiA 基因的同源物，表明该分离物可以降解群体感应Pss 3289 的信号分子。内生细菌 B. cereus (Si-Ps1) 的粗提取物在 48 和 96 小时后分别抑制 Pss 3289 生物膜形成 55% 和 58%。P. azotoformans (La-Pot3-3) 的粗提取物也赋予了生物膜形成类似的减少。相应地，用这些提取物处理的培养物中浮游细胞的数量高于对照培养物，表明对生物膜形成有直接影响，而不是对细胞生长有直接影响。在温室试验中，当与这些内生细菌共接种时，Pss 3289 对不同柑橘栽培品种的毒力降低。