Effects of luxCDABEG induction in Vibrio fischeri: enhancement of symbiotic colonization and conditional attenuation of growth in culture
Effects of luxCDABEG induction in Vibrio fischeri: enhancement of symbiotic colonization and conditional attenuation of growth in culture
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DOI：
10.1007/s00203-008-0387-1
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发表时间：
2008-08-01
影响因子：
2.8
通讯作者：
Stabb, Eric V.
中科院分区：
文献类型：
--
作者：
Bose, Jeffrey L.;Rosenberg, Charles S.;Stabb, Eric V.
理论上，生物发光的产生代表了可能减缓费氏弧菌生长的能量成本或其他成本;然而，生物发光也被认为能够使费氏弧菌完全共生定殖于Euprymna spiropes光器官。这些模型的先前测试已被证明是不确定的，部分原因是他们比较了非等基因菌株，或未定义和/或多效性突变体。为了测试产生生物发光的lux操纵子对生长和共生能力的影响，我们在菌株MJ 1和ES 114中产生了暗Delta luxCDABEG突变体，而不破坏luxR-luxI调节回路。MJ 1 Delta luxCDABEG突变体在碳限制恒化器中竞争其可见发光亲本，每代相似于26%。类似地，相对于Delta luxCDABEG突变体，在其他暗淡的ES 114菌株中诱导发光减缓了生长。一些培养条件下没有产生可检测到的发光对生长的影响，表明发光并不总是生长限制;然而，从未发现发光在培养中具有优势。与lux表达的这种条件性缺点相反，ES 114在E.我是说...这些结果表明，在一定的培养条件下，luxCDABEG的诱导可以减缓费氏弧菌的生长，并且是一种积极的共生定殖因子。
Production of bioluminescence theoretically represents a cost, energetic or otherwise, that could slow Vibrio fischeri growth; however, bioluminescence is also thought to enable full symbiotic colonization of the Euprymna scolopes light organ by V. fischeri. Previous tests of these models have proven inconclusive, partly because they compared nonisogenic strains, or undefined and/or pleiotropic mutants. To test the influence of the bioluminescence-producing lux operon on growth and symbiotic competence, we generated dark Delta luxCDABEG mutants in strains MJ1 and ES114 without disrupting the luxR-luxI regulatory circuit. The MJ1 Delta luxCDABEG mutant out-competed its visibly luminescent parent similar to 26% per generation in a carbon-limited chemostat. Similarly, induction of luminescence in the otherwise dim ES114 strain slowed growth relative to Delta luxCDABEG mutants. Some culture conditions yielded no detectable effect of luminescence on growth, indicating that luminescence is not always growth limiting; however, luminescence was never found to confer an advantage in culture. In contrast to this conditional disadvantage of lux expression, ES114 achieved similar to fourfold higher populations than its Delta luxCDABEG mutant in the light organ of E. scolopes. These results demonstrate that induction of luxCDABEG can slow V. fischeri growth under certain culture conditions and is a positive symbiotic colonization factor.