转录水平分析转速对克拉维酸发酵产量的影响机制

Characterization of Rotation Speed on the Fermentation Yield of Clavulanic Acid by Transcriptome Analysis

搅拌转速影响克拉维酸发酵水平,旨在研究搅拌转速影响棒状链霉菌F613-1克拉维酸(CA)生物合成的分子机制。采用转录组高通量测序,对比不同转速发酵条件之间的基因转录水平差异,分析克拉维酸代谢途径相关基因的转录水平变化。摇瓶发酵结果显示,高转速条件下F613-1的CA产量比低转速条件显著提高,发酵周期缩短。转录组分析显示,高转速条件下F613-1中CA合成基因簇中基因表达量无显著变化,但CA合成前体物质精氨酸和3-磷酸甘油醛代谢相关基因的转录水平发生显著变化,精氨酸合成基因簇中基因表达量明显升高,甘油代谢转化为3-磷酸甘油醛的基因表达量显著提高。因此,棒状链霉菌在高转速发酵条件下CA合成速度增加的主要原因是CA合成前体物质精氨酸和3-磷酸甘油醛的代谢活性增强和前体物质积累。

The rotation speed affects the fermentation yield of clavulanic acid(CA).This work aims to explore the molecular mechanism of rotation speed affecting the biosynthesis of CA in Streptomyces clavuligerus F613-1.Transcriptome high-throughput sequencing was adapted to assess the differential gene expressions of CA fermentation conditions between at high rotation speed and low rotation speed,and to analyze the changes in the transcription levels of genes related to the metabolic pathway of CA.The shaking fermentation assay showed that the CA yield at high rotation speed was significantly higher than that at low rotation speed,and the fermentation period of F613-1was shortened.Transcriptome analysis demonstrated that the gene expression level of genes in CA biosynthetic gene cluster had no significant change under the condition of high rotation speed when compared with the low rotation speed.But transcriptome analysis revealed that the expression level of genes involved in metabolism of arginine and glyceraldehyde 3-phosphate(G3P),two important CA precursors,significantly increased.Therefore,the main reason for the increase of CA biosynthesis in F613-1 under the high rotation speed fermentation condition is the accumulation of CA biosynthetic precursors,arginine and G3P,and the enhancement of arginine and G3P metabolic pathways.