Diversity of oxygen and N-oxide regulation of nitrite reductases in denitrifying bacteria

• Published in: FEMS microbiology letters Vol. 156; no. 1; pp. 55 - 60
• Main Authors: Ka, Jong-Ok, Urbance, John, Ye, Rick W, Ahn, Tae-Young, Tiedje, James M
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.11.1997
• Subjects: Aerobiosis; Anaerobiosis; Bacteria - genetics; Bacteria - growth & development; Bacteria - metabolism; Denitrification; Genes, Bacterial; Nitrite reductase activity; Nitrite Reductases - biosynthesis; Nitrite Reductases - metabolism; Nitrites - metabolism; Oxygen - metabolism; Oxygen regulation; Phylogeny; Pseudomonas aeruginosa; Pseudomonas aeruginosa - genetics; Pseudomonas aeruginosa - growth & development; Pseudomonas aeruginosa - metabolism; RNA, Bacterial - genetics; RNA, Ribosomal, 16S - genetics; Soil Microbiology; Denitrification; Nitrite reductase activity; Pseudomonas aeruginosa; Oxygen regulation
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1016/S0378-1097(97)00404-7

We examined α, β and γ Proteobacteria with Cu and heme-type dissimilatory nitrite reductases for patterns of nir regulation. Six of seven strains expressed nitrite reductase under aerobic growth conditions. In only one strain, G-179, was it stringently regulated by O 2. Growth with NO − 3 or NO − 2 enhanced nitrite reductase production in four of seven strains under anaerobic growth conditions, but in only one strain, Pseudomonas aeruginosa PA01, under aerobic conditions. In this strain the nitrite reductase production was primarily regulated by an anr gene when grown under anaerobic conditions, but when grown under aerobic conditions it was regulated by both an anr gene and nitrogen oxide. Constitutive production of nitrite reductase was a common phenomenon rather than the exception among denitrifiers from the environment, which helps explain the prevalence of denitrifying enzymes in aerobic soils.