Utilization of acyl-homoserine lactone quorum signals for growth by a soil pseudomonad and Pseudomonas aeruginosa PAO1
Utilization of acyl-homoserine lactone quorum signals for growth by a soil pseudomonad and Pseudomonas aeruginosa PAO1
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DOI：
10.1128/aem.69.10.5941-5949.2003
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发表时间：
2003-10-01
影响因子：
4.4
通讯作者：
Leadbetter, JR
中科院分区：
文献类型：
--
作者：
Huang, JJ;Han, JI;Leadbetter, JR
酰基高丝氨酸内酯（AHL）被几种变形菌用作群体感应信号。过去的研究已经确定，这些化合物会发生生化衰变，可用作生长营养素。在这里，我们描述了分离的土壤细菌，假单胞菌菌株PAI-A，降解3-氧代十二烷酰基-高丝氨酸内酯（3 OC 12 HSL）和其他长酰基，但不是短酰基，AHL作为唯一的能源增长。PAI-A菌株的小亚基rRNA基因与铜绿假单胞菌的小亚基rRNA基因有98.4%的同源性，但该土壤分离物不产生明显的色素和AHLs，也不生长于低温或42 ℃。检测了产生30 C12 HSL和C4 HSL的群体感应细菌铜绿假单胞菌利用AHL生长的能力。它的特异性类似于PAI-A菌株，即，降解长酰基而不是短酰基AHL。与用菌株PAI-A观察到的生长相反，铜绿假单胞菌菌株PAO 1在AHLs上的生长仅在极长的滞后期之后才开始。液相色谱-大气压化学电离-质谱分析表明，菌株PAO 1通过阿勒酰化酶和产生高丝氨酸的HSL内酯酶降解长酰基AHL。铜绿假单胞菌基因pvdQ（PA 2385）先前已被鉴定为描述为存在于罗尔斯通氏菌属物种中的阿勒酰化酶的同源物。表达pvdQ的大肠杆菌催化长酰基AHLs的快速失活和HSL的释放。被工程化以组成型表达pvdQ的铜绿假单胞菌在丰富培养基中生长时不积累其30 C12 HSL群体信号。然而，铜绿假单胞菌的pvdQ敲除突变体仍然能够通过利用30 C12 HSL生长。据我们所知，这是第一次报告的降解AHLs的假单胞菌或其他γ-变形菌，阿勒酰化酶活性在群体感应细菌，HSL内酯酶活性在任何细菌，和阿勒降解与特异性只对AHLs与长侧链。
Acyl-homoserine lactones (AHLs) are employed by several Proteobacteria as quorum-sensing signals. Past studies have established that these compounds are subject to biochemical decay and can be used as growth nutrients. Here we describe the isolation of a soil bacterium, Pseudomonas strain PAI-A, that degrades 3-oxododecanoyl-homoserine lactone (3OC12HSL) and other long-acyl, but not short-acyl, AHLs as sole energy sources for growth. The small-subunit rRNA gene from strain PAI-A was 98.4% identical to that of Pseudomonas aeruginosa, but the soil isolate did not produce obvious pigments or AHLs or grow under denitrifying conditions or at 42degreesC. The quorum-sensing bacterium P. aeruginosa, which produces both 3OC12HSL and C4HSL, was examined for the ability to utilize AHLs for growth. It did so with a specificity similar to that of strain PAI-A, i.e., degrading long-acyl but not short-acyl AHLs. In contrast to the growth observed with strain PAI-A, P. aeruginosa strain PAO1 growth on AHLs commenced only after extremely long lag phases. Liquid-chromatography-atmospheric pressure chemical ionization-mass spectrometry analyses indicate that strain PAO1 degrades long-acyl AHLs via an AHL acylase and a homoserine-generating HSL lactonase. A P. aeruginosa gene, pvdQ (PA2385), has previously been identified as being a homologue of the AHL acylase described as occurring in a Ralstonia species. Escherichia coli expressing pvdQ catalyzed the rapid inactivation of long-acyl AHLs and the release of HSL. P. aeruginosa engineered to constitutively express pvdQ did not accumulate its 3OC12HSL quorum signal when grown in rich media. However, pvdQ knockout mutants of P. aeruginosa were still able to grow by utilizing 3OC12HSL. To our knowledge, this is the first report of the degradation of AHLs by pseudomonads or other gamma-Proteobacteria, of AHL acylase activity in a quorum-sensing bacterium, of HSL lactonase activity in any bacterium, and of AHL degradation with specificity only towards AHLs with long side chains.