在氮剥夺(-N)下,蓝细菌集胞藻。PCC6803表现出生长停滞,蛋白质含量降低,显著增加糖原积累。然而,在这种条件下生产糖原需要两步过程,细胞从正常培养基转移到-N培养基。糖原快速积累的代谢工程和化学处理可以绕过两步培养的需要。例如,最近的研究表明,单独破坏氢(H2)或聚(3-羟基丁酸)(PHB)的合成,或用甲基紫精(MV)处理,有效增加集胞藻糖原的积累。在这里,我们探讨了破坏H2或聚(3-羟基丁酸酯)合成的影响,与MV处理一起,以增强在正常培养基中生长的集胞藻中的糖原积累。未经MV处理的野生型细胞表现出小于6%w/w干重(DW)的低糖原含量。与野生型相比,破坏PHB合成与MV处理相结合不会增加糖原含量。未经MV处理的中断的H2生产产生高达11%w/w的DW糖原含量。有趣的是,当合并时,用MV处理中断H2生产,在3天和7天内协同增强糖原积累至51%和59%w/wDW,分别。代谢组学分析表明MV处理介导了蛋白质向糖原的转化。代谢组学和转录表达分析表明在MV处理下破坏的H2合成积极影响糖原合成。在MV处理下中断的H2合成显着增加了NADPH水平。NADPH含量的增加可能有助于观察到针对MV诱导的氧化剂的抗氧化活性增强。O2的演变,和正常培养基中糖原合成的代谢底物水平,最终导致集胞藻糖原积累增强。关键信息:结合破坏的氢气合成和光合作用电子传输抑制剂的处理显着增强蓝细菌中糖原的产生。
Under nitrogen deprivation (-N), cyanobacterium Synechocystis sp. PCC 6803 exhibits growth arrest, reduced protein content, and remarkably increased glycogen accumulation. However, producing glycogen under this condition requires a two-step process with cell transfer from normal to -N medium. Metabolic engineering and chemical treatment for rapid glycogen accumulation can bypass the need for two-step cultivation. For example, recent studies indicate that individually disrupting hydrogen (H2) or poly(3-hydroxybutyrate) (PHB) synthesis, or treatment with methyl viologen (MV), effectively increases glycogen accumulation in Synechocystis. Here we explore the effects of disrupted H2 or poly(3-hydroxybutyrate) synthesis, together with MV treatment to on enhanced glycogen accumulation in Synechocystis grown in normal medium. Wild-type cells without MV treatment exhibited low glycogen content of less than 6% w/w dry weight (DW). Compared with wild type, disrupting PHB synthesis combined with MV treatment did not increase glycogen content. Disrupted H₂ production without MV treatment yielded up to 11% w/w DW glycogen content. Interestingly, when combined, disrupted H2 production with MV treatment synergistically enhanced glycogen accumulation to 51% and 59% w/w DW within 3 and 7 days, respectively. Metabolomic analysis suggests that MV treatment mediated the conversion of proteins into glycogen. Metabolomic and transcriptional-expression analysis suggests that disrupted H2 synthesis under MV treatment positively influenced glycogen synthesis. Disrupted H₂ synthesis under MV treatment significantly increased NADPH levels. This increased NADPH content potentially contributed to the observed enhancements in antioxidant activity against MV-induced oxidants, O2 evolution, and metabolite substrates levels for glycogen synthesis in normal medium, ultimately leading to enhanced glycogen accumulation in Synechocystis. KEY MESSAGE: Combining disrupted hydrogen-gas synthesis and the treatment by photosynthesis electron-transport inhibitor significantly enhance glycogen production in cyanobacteria.