Physiology, Biochemistry and Genetics of Nitrate Dissimilation to Ammonia

Author(s):  
J. A. Cole
1980 ◽  
Vol 40 (2) ◽  
pp. 429-430 ◽  
Author(s):  
J. C. Escalante-Semerena ◽  
Richard P. Blakemore ◽  
R. S. Wolfe

1962 ◽  
Vol 17 (3) ◽  
pp. 378-391 ◽  
Author(s):  
D. J. Greenwood

Microbiology ◽  
1982 ◽  
Vol 128 (10) ◽  
pp. 2463-2468 ◽  
Author(s):  
G. T. Macfarlane ◽  
R. A. Herbert

1972 ◽  
Vol 18 (12) ◽  
pp. 1783-1787 ◽  
Author(s):  
G. A. Jones

A mixed culture of bovine rumen microorganisms was incubated anaerobically, under conditions likely to support growth, with added nitrate and in the presence of several potential hydrogen donors known to be intermediates in the rumen fermentation. Reduction of nitrate via nitrite to ammonia was observed but there were marked differences in the relative rates and extent of nitrate and nitrite reduction in the presence of different hydrogen donors. The hydrogen donors were ranked in decreasing order of overall effectiveness for the complete reduction of nitrate and nitrite: formate > hydrogen > glucose [Formula: see text] lactate > succinate. Methane production in the cultures was markedly depressed in the presence of nitrate. The identification by gas chromatography of nitrous oxide in the gas phase of cultures containing nitrate and incubated with hydrogen, glucose, or lactate showed that the microbiota was capable of denitrification. The quantitative significance of denitrification as a pathway of nitrate dissimilation by rumen microorganisms, however, is probably small.


2007 ◽  
Vol 75 (8) ◽  
pp. 3780-3790 ◽  
Author(s):  
Nadine E. Van Alst ◽  
Kristin F. Picardo ◽  
Barbara H. Iglewski ◽  
Constantine G. Haidaris

ABSTRACT Infection by the bacterial opportunist Pseudomonas aeruginosa frequently assumes the form of a biofilm, requiring motility for biofilm formation and dispersal and an ability to grow in nutrient- and oxygen-limited environments. Anaerobic growth by P. aeruginosa is accomplished through the denitrification enzyme pathway that catalyzes the sequential reduction of nitrate to nitrogen gas. Mutants mutated in the two-component nitrate sensor-response regulator and in membrane nitrate reductase displayed altered motility and biofilm formation compared to wild-type P. aeruginosa PAO1. Analysis of additional nitrate dissimilation mutants demonstrated a second level of regulation in P. aeruginosa motility that is independent of nitrate sensor-response regulator function and is associated with nitric oxide production. Because motility and biofilm formation are important for P. aeruginosa pathogenicity, we examined the virulence of selected regulatory and structural gene mutants in the surrogate model host Caenorhabditis elegans. Interestingly, the membrane nitrate reductase mutant was avirulent in C. elegans, while nitrate sensor-response regulator mutants were fully virulent. The data demonstrate that nitrate sensing, response regulation, and metabolism are linked directly to factors important in P. aeruginosa pathogenesis.


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