Carbon source, cell density, and the microbial community control inhibition of surface colonization by environmental nitrate.

Unlabelled: The intestinal diarrheal pathogen colonizes the host terminal ileum, a microaerophilic, glucose-poor, nitrate-rich environment. In this environment, respires nitrate and increases transport and utilization of alternative carbon sources via the cAMP receptor protein (CRP), a transcription factor that is active during glucose scarcity. Here we show that nitrate respiration in aerated cultures is under control of CRP and, therefore, glucose availability.