Abstract

Pseudomonads are among the most common bacteria in soils, limnic ecosystems, and human, animal, or plant host environments, including intensively studied species such as Pseudomonas aeruginosa, P. putida, or P. fluorescens. Various gene expression systems are established for some species, but there is still a need for a simple system that is suitable for a wide range of pseudomonads and that can be used for physiological applications, i.e., with a tuning capacity at lower expression levels. Here, we report the establishment of the anthranilate-dependent P_antA promoter for tunable gene expression in pseudomonads. During studies on P. fluorescens, we constructed an anthranilate-inducible AntR/P_antA-based expression system, named pUCP20-ANT, and used GFP as reporter to analyze gene expression. This system was compared with the rhamnose-inducible RhaSR/P_rhaB-based expression system in an otherwise identical vector background. While the rhamnose-inducible system did not respond to lower inducer concentrations and always reached high levels over time when induced, expression levels of the pUCP20-ANT system could be adjusted to a range of distinct lower or higher levels by variation of anthranilate concentrations in the medium. Importantly, the anthranilate-inducible expression system worked also in strains of P. aeruginosa and P. putida and therefore will be most likely useful for physiological and biotechnological purposes in a wide range of pseudomonads.

Key points

• We established an anthranilate-inducible gene expression system for pseudomonads.

• This system permits tuning of gene expression in a wide range of pseudomonads.

• It will be very useful for physiological and biotechnological applications.

中文翻译：

---

假单胞菌种的可调节邻氨基苯甲酸诱导基因表达系统

摘要

假单胞菌是土壤，边缘生物生态系统以及人类，动物或植物宿主环境中最常见的细菌，包括经过深入研究的物种，例如铜绿假单胞菌，恶臭假单胞菌或荧光假单胞菌。对于某些物种已经建立了各种基因表达系统，但是仍然需要一种简单的系统，该系统适用于广泛的假单胞菌并且可以用于生理学应用，即在较低表达水平下具有调节能力。在这里，我们报告为假单胞菌可调基因表达的邻氨基苯甲酸依赖的P _antA启动子的建立。在研究荧光假单胞菌的过程中，我们构建了邻氨基苯甲酸诱导的AntR /基于P _antA的表达系统，名为pUCP20-ANT，并使用GFP作为报告基因来分析基因表达。在其他相同的载体背景下，将该系统与鼠李糖诱导的RhaSR / P _rhaB基表达系统进行了比较。尽管鼠李糖诱导系统对较低的诱导物浓度无反应，并在诱导时随时间推移始终达到高水平，但pUCP20-ANT系统的表达水平可通过改变邻苯二甲酸酯的邻氨基苯甲酸酯浓度而调整为一系列明显的较低或较高水平。中。重要的是，邻氨基苯甲酸诱导表达系统在铜绿假单胞菌和恶臭假单胞菌的菌株中也起作用 因此，很可能将其用于多种假单胞菌的生理和生物技术用途。

关键点

•我们为假单胞菌建立了邻氨基苯甲酸诱导的基因表达系统。

•该系统可以调节多种假单胞菌的基因表达。

•对于生理和生物技术应用将非常有用。