Due to the limiting natural resources, greenhouse effect and global warming crisis, the bio-based chemicals which are environmentally friendly materials have gradually become urgent and important. Cadaverine, a 1,5-diaminopentane (DAP), is widely used as block chemicals for synthesis of biopolymer, which can be produced from lysine by lysine decarboxylase (EC 4.1.1.18) in Escherichia coli. However, the DAP will be further utilized into by-products through downstream genes of speE, puuA, speG and ygjG, which decrease the amount of product. In this study, two approaches including Lambda-Red system for gene knockout, and clustered regularly interspaced short palindromic repeats interference (CRISPRi) for gene knockdown; are explored to manipulate the metabolic flux among 26 genetic E. coli. As a result, CadA driven by inducible T7 promoter accumulated more DAP from CRISPRi targeted on single-gene repressive strains such as BT7AiE, BT7AiP, BT7AiG and BT7AiY. The highest DAP titer and productivity was obtained to 38 g/L and 2.67 g/L/h in BT7AiY (repression of ygjG). We also investigated the co-factor pyridoxal 5′-phosphate (PLP) effect on lysine consumption and DAP production from different E. coli derivatives. In contrast to CRISPRi-mediated strains, 4 genes knockout strain (BT7AdEPGY) deal with 98% lysine consumption and achieved 37.45 g/L DAP and 3.17 g/L/h DAP productivity. The metabolic regulation by CRISPRi is a simple strategy and the results are consistent with gene knockout to manipulate the pathway for DAP production.

由于有限的自然资源，温室效应和全球变暖危机，作为环境友好材料的生物基化学物质已逐渐变得迫切和重要。Cadaverine是一种1,5-二氨基戊烷（DAP），广泛用作合成生物聚合物的嵌段化学品，可以通过赖氨酸脱羧酶（EC 4.1.1.18）在大肠杆菌中由赖氨酸生产。但是，DAP将通过spe E，puu A，spe G和ygj的下游基因进一步用于副产物中。G，减少了产品量。在这项研究中，两种方法包括用于基因敲除的Lambda-Red系统和用于基因敲除的聚类规则间隔的短回文重复序列干扰（CRISPRi）。探索操纵26种遗传大肠杆菌之间的代谢通量。结果，由可诱导的T7启动子驱动的CadA从CRISPRi累积了更多的DAP，这些DAP靶向BT7AiE，BT7AiP，BT7AiG和BT7AiY等单基因抑制菌株。在BT7AiY（ygj G的抑制）中，最高的DAP滴度和生产率达到38 g / L和2.67 g / L / h 。我们还研究了辅因子吡ido醛5'-磷酸（PLP）对不同大肠杆菌中赖氨酸消耗和DAP产生的影响衍生品。与CRISPRi介导的菌株相比，有4个基因敲除菌株（BT7A​​dEPGY）消耗98％的赖氨酸，达到37.45 g / L DAP和3.17 g / L / h DAP生产率。CRISPRi的代谢调节是一种简单的策略，其结果与基因敲除操作DAP产生途径的过程一致。