摘要 粘质沙雷氏菌能在30℃高效合成灵菌红素,但在37℃甚至更高温度则丧失合成能力。研究表明,在37℃甚至更高温度下,粘质沙雷氏菌中灵菌红素合成关键酶氧甲基转移酶(O-methyltransferase,PigF)的表达量显著下降。因此,通过人工在pigF基因3′端添加6条不同的poly(A/T)尾来提高pigF基因mRNA稳定性,并观察其对粘质沙雷氏菌中PigF表达量及灵菌红素合成的影响。结果发现,添加“AAAAAA”可以保护mRNA免受降解,从而使得pigF转录水平提高71%。其次,添加“AAAAAA”后,PigF比酶活力提高了41.8%。最后通过摇瓶发酵,实验结果表明,与30℃培养的原始菌株相比,工程改造的JNB5-1/pigF FP菌株的灵菌红素产量达到6.21 g/L,提高了15.9%。该研究表明,通过引入poly(A/T)尾提高了PigF的表达量,进而提高了粘质沙雷氏菌合成灵菌红素的能力。 Serratia marcescens can efficiently synthesize prodigiosin at 30℃but lose this ability at 37℃.The expression of the key enzyme,O-methyltransferase(PigF),in the prodigiosin synthesis gene cluster was significantly reduced.In this study,six different poly(A/T)tails were added to the 3'end of pigF gene to improve mRNA stability of pigF gene,and the effect on the expression of O-methyltransferase and the synthesis of prodigiosin in S.marcescens was //confirm/i/ied.The result showed that the transcriptional level of pigF was increased by 71%because the addition of“AAAAAA”can protect mRNA from degradation.Furthermore,it was found that the activity of PigF increased by 41.8%after adding“AAAAAA”.In shake flask fermentation of engineered strain JNB5-1/pigF FP,the titer of prodigiosin reached 6.21 g/L,which was 15.9%higher than that of the start strain JNB5-1.The results indicate that introduction of poly(A/T)tails can effectively increase the expression of PigF,thereby enhancing the synthesis of prodigiosin in S.marcescens.
出处 《食品与发酵工业》 CAS CSCD 北大核心 2021年第9期49-56,共8页 Food and Fermentation Industries
基金 国家自然科学基金项目(31870066,21778024)。
关键词 粘质沙雷氏菌 灵菌红素 氧甲基转移酶(PigF) 温度 Serratia marcescens prodigiosin O-methyltransferase(PigF) polyadenylation temperature
分类号 TQ9 [化学工程]
