【摘要】 目的：以节杆菌Arthrobacter sp. CCTCC 2013431为研究对象，探究低聚磷酸盐作为能量供体促进环磷酸腺苷（cyclic adenosine monophosphate, cAMP）发酵合成的作用机理。方法：在7 L发酵罐中添加低聚磷酸盐，对发酵性能、转录组学、关键酶活性以及重要代谢物水平进行分析，揭示低聚磷酸盐促进cAMP发酵合成的机理。结果：发酵24 h添加2 g/L六偏磷酸钠，cAMP产量显著提高，达到3.64 g/L,与对照组相比提高了33.82%。转录组数据分析表明，由于六偏磷酸钠的添加，227个基因表达量显著上调，265个基因表达量显著下调；磷酸戊糖途径和cAMP合成途径中多数酶编码基因的转录水平，电子传递链中复合体Ⅲ、复合体IV和F₀F₁-ATP酶以及聚磷酸盐激酶编码基因的转录水平，硫氧还蛋白、过氧化氢酶及CLP蛋白酶等编码基因的转录水平均显著提高。此外，对丙酮酸激酶、6-磷酸葡萄糖脱氢酶、腺苷琥珀酸合成酶、腺苷酸环化酶、过氧化氢酶、聚磷酸盐激酶活性以及胞内活性氧、ATP和NADPH等进行测定，进一步证明了转录组分析结果。结论：六偏磷酸钠能够强化磷酸戊糖途径与cAMP合成途径，提高ATP供应，同时维持胞内氧化还原平衡，促进产物合成与积累。更多还原

【Abstract】 Objective: To explore the mechanism for enhanced cAMP fermentation production by polyphosphates, Arthrobacter sp. CCTCC 2013431 culture was carried out under low-polyphosphates addition condition as the starting strain. Methods: Fermentations with/without hexametaphosphate addition were conducted in a 7 L bioreactor and the fermentation performance, global gene transcriptome, key enzymes activities together with important metabolites levels were analyzed systematically. Results: With 2 g/L-broth sodium hexametaphosphate added at 24 h, cAMP concentration reached 3.64 g/L with an increment of 33.82% higher than that of control group and the fermentation performance was also promoted obviously. Transcriptome analysis showed that 227 genes were up-regulated significantly and 265 genes were down-regulated significantly due to the addition of hexametaphosphate. For glycometabolism, the transcription levels of key enzyme genes in pentose phosphate pathway and cAMP synthesis pathway were enhanced significantly and for energy metabolism the transcription levels of complex Ⅲ, complex Ⅳ as well as F₀F₁-ATPase in electron transport chain and polyphosphate kinase gene were also increased significantly by which sufficient carbon skeleton and ATP were provided for cAMP biosynthesis. In addition, transcription levels of reductase genes, such as thioredoxin, catalase and CLP protease, were also increased significantly whereby intracellular redox balance was maintained conducive to cell metabolism and product synthesis. Finally, the activities of pyruvate kinase, 6-phosphoglucose dehydrogenase, adenylosuccinate synthetase, adenylate cyclase, catalase, polyphosphate kinase and intracellular ROS, ATP and NADPH levels under different fermentation conditions were measured to further support the transcriptome analysis results. Conclusion: Sodium hexametaphosphate addition enhanced the carbon flux distribution in pentose phosphate pathway and cAMP synthesis pathway and energy metabolism for ATP synthesis. At the same time, intracellular redox balance was also maintained. Furthermore, cAMP fermentation synthesis and accumulation was promoted significantly.更多还原