Fig. 4

Schematic overview transcriptomic and metabolomic responses in S. lividans producing CelA. S. lividans containing pIJ486-vsi-celA shows stress responses linked to secretion and DNA damage, increased fluxes through the pentose phosphate pathway (PPP) and the tricarboxylic acid (TCA) cycle, and increasing expression of the OsdR regulon throughout the exponential phase. A series of PPP enzymes linked to secondary metabolism was found to be co-expressed with the OsdR regulon. The increased fluxes through the PPP and TCA cycle lead to an increased NADPH production, which can only be partly be attributed to higher NADPH need for additional protein synthesis. Surplus NADPH is assumed to be reoxidized, yet the mechanism for reoxidation of NADPH in S. lividans remains unknown