Fig. 5: Metabolic pathway redirection via tunable Tl-CRISPRi for enhancing the production of 3-HP.

All of the experiments shown in this figure were performed based on the acid-resistant strain E. coli W. a Overall pathway for synthesizing 3-HP from the glucose by utilizing malonyl-CoA reductase (mcr) and its neighboring pathways (TCA cycle, fatty acid synthesis cycle, etc.). All of the target genes of the Tl-CRISPRi were annotated in this figure. b The 3-HP titer of each strain when the Tl-CRISPRi knocked down each gene target. We selected five genes (fabI, fabZ, aceE, pfkB, metB), of which the knockdown exhibits a notable improvement of 3-HP titer, for further experiments. c The Tl-CRISPRi simultaneously knocked down two genes from the five selected candidates in (b). d To fine-tune the expression level of the fabI gene, 16 different guide RNAs consisting of eight different DR sequences and the two fabI spacers (spv1 and spv2) were adopted. The 3-HP titer and the OD₆₀₀ were measured after 24 h of the induction of the mcr gene. The error bar represents the mean ± standard deviation from the biologically independent cell cultures (n = 3), and the white dots indicate the actual data points. Source data are provided as a source data file.