Fig. 4

NMN⁺ accumulation affects cell physiology possibly via NadR. To determine if NMN⁺ accumulation impacts cell fitness, NMN⁺ was titrated in the growth medium of cells expressing the NMN⁺ transporter S. enterica PnuC*. The ΔpncC strain exhibited decreased growth at high NMN⁺ concentrations. Disruption of nadR significantly alleviated the growth inhibition. This suggests the NadR may mediate the physiological response to NMN⁺ accumulation in E. coli. Cells were grown at 30 °C for 6.5 h in a deep-well 96-well plate containing 1 mL of medium per well