碳源影响水稻根际假单胞菌PA1201藤黄绿菌素的生物合成

Effects of carbon sources on pyoluteorin biosynthesis in rice rhizobacterium Pseudomonas strain PA1201

摘要:

【背景】假单胞菌PA1201是一株水稻根际促生菌，其产生的次生代谢物藤黄绿菌素(pyoluteorin，Plt)能够有效抑制多种植物病原真菌和细菌的生长，但在常规培养条件下Plt产量极低。【目的】研究碳源对Plt生物合成的影响，为提高Plt的产量以及应用提供理论基础。【方法】将基本培养基(minimal medium，MM)中甘露醇替换为不同的碳源及碳源组合作为PA1201的培养基，生长过程中不同时间点取样提取Plt，利用高效液相色谱(HPLC)法分析Plt的产量变化。【结果】建立了基于HPLC定性和定量检测Plt的方法；比较了PA1201菌株在不同培养基中菌株生长和Plt的产量，发现果糖和甘露醇促进Plt生物合成；果糖和甘露醇对Plt生物合成没有增效作用；在含有甘露醇或果糖作为唯一碳源的培养基中，添加葡萄糖或琥珀酸抑制Plt生物合成。【结论】果糖和甘露醇促进水稻根际假单胞菌PA1201合成藤黄绿菌素，这为提高藤黄绿菌素的生物合成效率和促进藤黄绿菌素的应用奠定了基础。

Abstract:

[Background] Pseudomonas PA1201 strain is a plant growth promoting rhizobacterium isolated from rice rhizosphere. Pyoluteorin (Plt) is one of the secondary metabolites produced by PA1201, which can effectively inhibit the growth of a variety of phytopathogenic fungi and bacteria. Under normal culture conditions, Plt yield is extremely low. [Objective] This study aimed to analyze the effects of different carbon sources for optimal Plt biosynthesis. [Methods] PA1201 was cultured in minimal medium (MM) supplemented with different carbon sources as the sole carbon source, or MM medium with different combinations of carbon sources. Plt was extracted at different time points after inoculation, and then quantitatively analyzed by high-performance liquid chromatography (HPLC). [Results] A HPLC-dependent method for quantitative analysis of Plt levels was established; MM medium supplemented with fructose and mannitol were found to be optimal for Plt production; no additive effect between fructose and mannitol was observed on Plt biosynthesis; In the MM medium containing mannitol or fructose, addition of glucose or succinic acid inhibited Plt biosynthesis. [Conclusion] Fructose and mannitol promote the synthesis of Plt in rice rhizobacterium Pseudomonas PA1201, laying a foundation for improving the biosynthesis efficiency of pyoluteorin and promoting the application of pyoluteorin.