灵菌红素具有抗细菌和抗肿瘤等功能，在自然界主要由微生物合成。本项目组前期筛选得到一株产灵菌红素菌株Serratia marcescens JNB5-1，该菌合成灵菌红素受温度调控，28℃灵菌红素产量为6.49 g/L，37℃仅为0.14 g/L。关于温度调控粘质沙雷氏菌合成灵菌红素的机制目前尚不清楚。本项目拟在前期发现LysR家族转录因子LrpG在影响温度调控粘质沙雷氏菌合成灵菌红素的重要作用基础上，组合比较转录组学分析、ChIP-Seq、RT-qPCR、融合报告基因构建、EMSA和GST Pull-down assay等技术解析LrpG调控粘质沙雷氏菌合成灵菌红素的作用靶点和信号通路。组合lrpG-lacZ融合报告基因构建和Tn5G转座子插入等技术确定lrpG受温度调控上游基因。在解析温度调控粘质沙雷氏菌合成灵菌红素分子机理基础上，利用系统代谢工程策略构建37℃高产灵菌红素粘质沙雷氏菌。

Prodigiosin, which has important functions such as antibacterial and antitumor, is mainly synthesized by microorganism in nature. In our previous work, a strain Serratia marcescens JNB5-1, capable of producing prodigiosin effectively was isloated. The prodigiosin production of this strain was regulated by temperature dramatically. S. marcecens JNB5-1 can produce 6.49 g/L prodigiosin at 28°C, while that is only 0.14 g/L at 37°C. The molecular mechanisms how the temperature regulate the Serratia marcescens synthesis of prodigiosin remain unclear. In our previous work, we had identified that LysR family transcriptional regulator LrpG plays an important role in affecting temperature regulation of Serratia marcescens biosynthesis of prodigiosin. In this project, we will combination of comparative transcriptional assay, ChIP-Seq assay, RT-qPCR, fusion reporter gene construction, EMSA and GST Pull-down assay to determine the binding site and signal pathway of LrpG regulates Serratia marcescens production prodigiosin. Combination of lrpG-lacZ fusion reporter gene construction and Tn5G transposon insertion mutation technique to determine the upstream regulatory gene of lrpG controlled by temperature. Based on unravel the molecular mechanism of temperature controlling the Serratia marcescens biosynthesis prodigiosin, we will construct a 37℃ high yield prodigiosin producing strain by systematic metabolic engineering control strategy.