Flavodoxins are low-potential electron donors to a number of redox enzymes. FldP protects the cell from oxidative stress and reactive oxygen species (ROS) damage, thereby expanding the capabilities of P.aeruginosa to thrive in hostile environments, and contributes to bacterial survival within the host. In vitro, is able to mediate ferredoxin-NADP(H) reductase (FNR)-driven cytochrome c reduction. Up-regulated by oxidative stress conditions through an OxyR-independent mechanism. Makes part of an operon that consists of PA14_22510 to PA14_22540. Is repressed by the LysR-like transcriptional regulator PA14_22550. Cells lacking this gene accumulate higher intracellular ROS levels and exhibit decreased tolerance to H(2)O(2) toxicity compared to wild-type siblings. Inactivation of this gene also produces a moderate but significant decrease of 24% in the intracellular survival of P.aeruginosa in phagocytic cells. During in vivo infection of Drosophila melanogaster, flies that have been fed with the wild-type strain of P.aeruginosa die faster than those fed with the fldP deletion mutant. Belongs to the FldP flavodoxin family.