benefits from the bile salt deoxycholate under low-oxygen condition in a PldA dependent manner.

Enteric bacteria need to adapt to endure the antibacterial activities of bile salts in the gut. Phospholipase A (PldA) is a key enzyme in the maintenance of bacterial membrane homeostasis. Bacteria respond to stress by modulating their membrane composition. is the most common cause of human worldwide. However, the mechanism by which adapts and survives in the gut environment is not fully understood. In this study, we investigated the roles of PldA, bile salt sodium deoxycholate (DOC), and oxygen availability in biology, mimicking an situation. Growth curves were used to determine the adaptation of to bile salts. RNA-seq and functional assays were employed to investigate the PldA-dependent and DOC-induced changes in gene expression that influence bacterial physiology. Survival studies were performed to address oxidative stress defense in . Here, we discovered that PldA of is required for optimal growth in the presence of bile salt DOC. Under high oxygen conditions, DOC is toxic to , but under low oxygen conditions, as is present in the lumen of the gut, benefits from DOC. PldA seems to enable the use of iron needed for optimal growth in the presence of DOC but makes the bacterium more vulnerable to oxidative stress. In conclusion, DOC stimulates growth under low oxygen conditions and alters colony morphology in a PldA-dependent manner. benefits from DOC by upregulating iron metabolism in a PldA-dependent manner.