温度对粘质沙雷氏菌合成灵菌红素的影响

Effect of temperature on prodigiosin synthesis in Serratia marcecens

摘要:

摘要: 【目的】研究粘质沙雷氏菌(Serratia marcecens JNB5-1)在不同发酵温度(28℃ 和37℃)条件下蛋白质组的差异表达，探究粘质沙雷氏菌合成灵菌红素受温度调控的原因。【方法】利用二维凝胶电泳(2-DE)和基质辅助激光解析电离飞行时间串联质谱技术(MALDI-TOF-MS)分离和鉴定粘质沙雷氏菌在不同发酵温度(28℃和37℃)条件下的差异蛋白; 再利用实时荧光定量PCR(RT-qPCR)进一步分析挑选出的七个差异蛋白编码基因的转录水平。【结果】2-DE图谱显示，共鉴定到16个显著差异的蛋白点。其中，灵菌红素合成途径中的氧甲基转移酶(PigF)、氧化还原酶(PigN) 和参与灵菌红素前体物质(脯氨酸、甲硫氨酸、丝氨酸、二辛烯醛和丙二酰-CoA 等)代谢的相关蛋白(酶)的表达量在37℃条件下都出现极显著的下降; 热休克蛋白(Hsp60)、超氧化物歧化酶(Superoxide dismutase)等应急性蛋白在37℃条件下表达上调。通过ＲT-qPCR证实，氧甲基转移酶、氧化还原酶和转酮醇酶基因(transketolase)在37℃条件下的转录水平均低于28℃条件下的。【结论】S.marcecens JNB5-1在相对低温(28℃)条件下产灵菌红素，相对高温( 37℃)条件下不产灵菌红素。可能是高温(37℃)显著抑制了灵菌红素合成相关酶的表达。

Abstract:

Abstract: ［Objective］ To study the effect of temperature on prodigiosin synthesis in Serratia marcecens JNB5-1．［Methods］Different proteins obtained after culturing S．marcecens JNB5-1at 28 ℃ and 37 ℃ were separated and identified through two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry．Subsequently，7 of the proteins were further analyzed by real-time qPCR．［Ｒesults］ We identified 16 different proteins． Among them，prodigiosin biosynthetic enzymes (O-methyl transferase and Oxidoreductase) and proteins related with the precursor substances (proine，methionine，serine，2-Octenal and Malonyl-CoA) of the prodigiosin biosynthetic were significantly down-expressed at 37℃．Heat shock protein (Hsp60) and superoxide dismutase were upexpressed at 37 ℃．The results of real-time qPCR show that the mRNA transcriptional levels of o-methyl transferase，oxidoreductase and transketolase at 37 ℃ were all lower than that at 28 ℃．［Conclusion］ S.marcecens JNB5-1 could produce prodigiosin at lower temperature (28℃) but not at higher temperature (37 ℃)．Higher temperature probably inhibited the expression of enzymes related with prodigiosin biosynthesis.