Fig. 5
Overproduction of inosine by enhancing the metabolic flow of PPP. a Inosine productions of the engineered strains by knocking out the ywjH gene and overexpressing the zwf gene. b The effect of linearly assembling proteins GlcK, Zwf, and YkgB on the inosine synthesis and cell growth. The protein scaffolds GBD, SH3, and PDZ were separately used to linearly assemble proteins GlcK, Zwf, and YkgB. c The effect of the pgi expression level on the inosine synthesis and cell growth. Conditional expression of the pgi gene under the control of the Pxyl promoter was used to balance the inosine synthesis and cell growth. d Two-stage fermentation in the inosine engineered strain by the pgi-based metabolic switch. All error bars indicate ± SD, n = 3. A value of P less than 0.05 was regarded to be a significant difference with the W168 strain using the T-test (*, P < 0.05; **, P < 0.01)