转录组测序分析氯化钠对普鲁兰生物合成的影响

Understanding the Effect of Sodium Chloride on Pullulan Biosynthesis by RNA Sequencing

考察氯化钠对出芽短梗霉生物合成普鲁兰的影响,结果发现氯化钠有助于提高普鲁兰产量,但不利于将普鲁兰分子质量维持在较高水平。与对照组(0 g/L氯化钠)相比,实验组(3 g/L氯化钠)的普鲁兰分批发酵产量提高了17.6%,而普鲁兰最终分子质量却降低了55.8%。对出芽短梗霉细胞的转录组进行测序和分析,共鉴别出659个显著性差异表达基因,其中实验组有227个基因表达上调,有432个基因表达下调。对这些差异表达基因进行基因本体论(Gene Ontology,GO)功能注释和京都基因和基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)数据库通路富集分析,结果表明氯化钠影响了部分水解酶和具有离子、小分子绑定功能蛋白编码基因的表达水平,这些基因参与碳水化合物代谢、淀粉和蔗糖代谢、糖酵解/糖异生等代谢过程,最终导致普鲁兰产量和分子质量的显著变化。

The effect of sodium chloride(NaCl)on pullulan biosynthesis by Aureobasidium pullulans CCTCC M 2012259 in shaking flasks was investigated.NaCl was found to be conducive to pullulan production,but was unfavorable to maintain the molecular mass of pullulan at a high level.The results of batch fermentation showed that pullulan production increased by 17.6%in the experimental group(3 g/L NaCl),while the molecular mass of pullulan finally obtained decreased by 55.8%,as compared to the control group(0 g/L NaCl).Based on the RNA sequencing(RNA-Seq)analysis of A.pullulans,a total of 659 significantly differentially expressed genes(DEGs)were identified between the two groups,of which 227 genes were up-regulated while the remaining 432 were down-regulated in the experimental group.Gene Ontology(GO)functional annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis of these DEGs indicated that NaCl regulated the expression of genes encoding certain hydrolases as well as ion and small molecule-binding proteins.These genes participated in carbohydrate,starch and sucrose metabolism,and glycolysis/gluconeogenesis,resulting in significant changes in the production and molecular mass of pullulan.