Tunable control of gene expression is an invaluable tool for biological experiments. In this study, we describe a new xylose-inducible promoter system and evaluate it in both Pseudomonas aeruginosa and Pseudomonas fluorescens. The P_xut promoter, derived from the P. fluorescens xut operon, was incorporated into a broad-host-range pBBR1-based plasmid and was compared to the Escherichia coli-derived P_BAD promoter using gfp as a reporter. Green fluorescent protein (GFP) fluorescence from the P_xut promoter was inducible in both Pseudomonas species, but not in E. coli, which may facilitate the cloning of genes toxic to E. coli to generate plasmids. The P_xut promoter was activated at a lower inducer concentration than P_BAD in P. fluorescens, and higher gfp levels were achieved using P_xut. Flow cytometry analysis indicated that P_xut was leakier than P_BAD in the Pseudomonas species tested but was expressed in a higher proportion of cells when induced. d-Xylose as a sole carbon source did not support the growth of P. aeruginosa or P. fluorescens and is less expensive than many other commonly used inducers, which could facilitate large-scale applications. The efficacy of this system was demonstrated by its use to reveal a role for the P. aeruginosa type II secretion system gene xcpQ in bacterial inhibition of corneal epithelial cell wound closure. This study introduces a new inducible promoter system for gene expression for use in Pseudomonas species.

中文翻译：

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用于假单胞菌属物种的木糖诱导型启动子工具及其在暗示II型分泌系统蛋白XcpQ在抑制角膜上皮伤口闭合中的作用中的用途。

基因表达的可调控制是生物学实验的宝贵工具。在这项研究中，我们描述了一种新的木糖诱导型启动子系统，并在铜绿假单胞菌和荧光假单胞菌中对其进行了评估。将源自荧光假单胞菌操纵子的P _xut启动子掺入基于广泛宿主的基于pBBR1的质粒，并使用gfp作为报告子与大肠杆菌衍生的P _BAD启动子进行比较。P _xut启动子发出的绿色荧光蛋白（GFP）荧光在两种假单胞菌物种中均可诱导，但在 大肠杆菌，可能有助于克隆对大肠杆菌有毒的基因以产生质粒。的P _XUT启动子被在较低的诱导剂浓度高于激活P _BAD在荧光假单胞菌，以及更高的GFP使用分别实现水平P _XUT。流式细胞仪分析表明，在所测试的假单胞菌属物种中，P _xut比P _BAD泄漏，但在诱导时以较高比例的细胞表达。d-木糖作为唯一碳源不支持铜绿假单胞菌或荧光假单胞菌并且比许多其他常用的诱导剂便宜，这可以促进大规模的应用。该系统的功效通过其用于揭示铜绿假单胞菌II型分泌系统基因xcpQ在细菌抑制角膜上皮细胞伤口闭合中的作用而证明。这项研究介绍了一种新的诱导型启动子系统，用于假单胞菌属物种的基因表达。