Switch of metabolic status: redirecting metabolic flux for acetoin production from glycerol by activating a silent glycerol catabolism pathway.
Switch of metabolic status: redirecting metabolic flux for acetoin production from glycerol by activating a silent glycerol catabolism pathway.
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DOI：
10.1016/j.ymben.2016.10.020
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发表时间：
2017
影响因子：
8.4
通讯作者：
Yu Wang;Fei Tao;Bo Xin;Hongyu Liu;Yanyan Gao;N. Zhou;P. Xu
中科院分区：
文献类型：
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作者：
Yu Wang;Fei Tao;Bo Xin;Hongyu Liu;Yanyan Gao;N. Zhou;P. Xu
沉默基因的生理功能仍是一个未解之谜，其应用潜力尚未被发掘。在此，由glp系统编码的沉默甘油催化剂途径在肺炎克雷伯氏菌突变体中被激活，其中乙偶姻降解途径被阻断。令人惊讶的是，激活产生了显着的影响，细胞代谢和超过90%的碳通量被重定向到乙偶姻的生物合成，这是以前的一个次要产品在这个突变体。转录分析表明，参与乙偶姻，1，3-丙二醇和腺苷钴胺素生物合成的基因在glp系统激活后受到不同的调节，证明了沉默途径和活性途径之间的相互作用。通过途径、辅因子和生物过程工程，实现了从甘油高水平生产乙偶姻（32.2 g L−1，理论值的90.8%）。我们的研究结果表明，一些沉默基因代表了细胞代谢状态的未探索开关，激活它们可能是将微生物重编程为高效细胞工厂的简单策略。
The physiological roles of silent genes are still unsolved puzzles and their application potentials are unexplored. Herein, a silent glycerol catabolism pathway encoded byglpsystem was activated in a Klebsiella pneumoniae mutant, of which the acetoin degradation pathway was blocked. Surprisingly, the activation produced significant effects on cellular metabolism and over 90% of the carbon flux was redirected to acetoin biosynthesis, which was formerly a minor product in this mutant. Transcription analyses suggest that the genes involved in acetoin, 1,3-propanediol and adenosyl-cobalamin biosynthesis were differentially regulated upon theglpsystem activation, demonstrating the cross-talk between silent and active pathways. Through pathway, cofactor and bioprocess engineering, high-level acetoin production from glycerol (32.2 g L−1, 90.8% of the theoretical value) was achieved. Our findings suggest that some silent genes represent unexplored switches of cellular metabolic status and activating them may be an easy strategy for reprogramming microorganisms into efficient cell factories.