Compensatory periplasmic nitrate reductase activity supports anaerobic growth of Pseudomonas aeruginosa PAO1 in the absence of membrane nitrate reductase.

ABSTRACT: Nitrate serves as a terminal electron acceptor under anaerobic conditions in Pseudomonas aeruginosa. Reduction of nitrate to nitrite generates a transmembrane proton motive force allowing ATP synthesis and anaerobic growth. The inner membrane-bound nitrate reductase NarGHI is encoded within the narK1K2GHJI operon, and the periplasmic nitrate reductase NapAB is encoded within the napEFDABC operon. The roles of the 2 dissimilatory nitrate reductases in anaerobic growth, and the regulation of their expressions, were examined by use of a set of deletion mutants in P. aeruginosa PAO1. NarGHI mutants were unable to grow anaerobically, but plate cultures remained viable up to 120 h. In contrast, the nitrate sensor-response regulator mutant DeltanarXL displayed growth arrest initially, but resumed

SUBMITTER: Van Alst NE 

PROVIDER: S-EPMC2831470 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature