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

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.