Nitrate Reductase and Nitrous Oxide Production by Fusarium oxysporum 11dn1 Under Aerobic and Anaerobic Conditions

2000 ◽  
Vol 41 (2) ◽  
pp. 114-119 ◽  
Author(s):  
Alexander V. Kurakov ◽  
Alexander N. Nosikov ◽  
Evdokiya V. Skrynnikova ◽  
Nicolay P. L'vov
Keyword(s):  
Nitrous Oxide ◽  
Nitrate Reductase ◽  
Fusarium Oxysporum ◽  
Anaerobic Conditions ◽  
Oxide Production ◽  
Nitrous Oxide Production ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

scholarly journals Mycobacterium smegmatis does not display functional redundancy in nitrate reductase enzymes

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245745
Author(s):  
Nicole C. Cardoso ◽  
Andrea O. Papadopoulos ◽  
Bavesh D. Kana
Keyword(s):  
Nitrate Reductase ◽  
Mycobacterium Smegmatis ◽  
Reductase Activity ◽  
Nitrate Assimilation ◽  
Anaerobic Conditions ◽  
Relative Contribution ◽  
Allelic Replacement ◽  
Encoding Genes ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Reduction of nitrate to nitrite in bacteria is an essential step in the nitrogen cycle, catalysed by a variety of nitrate reductase (NR) enzymes. The soil dweller, Mycobacterium smegmatis is able to assimilate nitrate and herein we set out to confirm the genetic basis for this by probing NR activity in mutants defective for putative nitrate reductase (NR) encoding genes. In addition to the annotated narB and narGHJI, bioinformatics identified three other putative NR-encoding genes: MSMEG_4206, MSMEG_2237 and MSMEG_6816. To assess the relative contribution of each, the corresponding gene loci were deleted using two-step allelic replacement, individually and in combination. The resulting strains were tested for their ability to assimilate nitrate and reduce nitrate under aerobic and anaerobic conditions, using nitrate assimilation and modified Griess assays. We demonstrated that narB, narGHJI, MSMEG_2237 and MSMEG_6816 were individually dispensable for nitrate assimilation and for nitrate reductase activity under aerobic and anaerobic conditions. Only deletion of MSMEG_4206 resulted in significant reduction in nitrate assimilation under aerobic conditions. These data confirm that in M. smegmatis, narB, narGHJI, MSMEG_2237 and MSMEG_6816 are not required for nitrate reduction as MSMEG_4206 serves as the sole assimilatory NR.

scholarly journals Enzymatic Removal of Nitric Oxide Catalyzed by Cytochrome c′ in Rhodobacter capsulatus

2001 ◽  
Vol 183 (10) ◽  
pp. 3050-3054 ◽  
Author(s):  
Richard Cross ◽  
David Lloyd ◽  
Robert K. Poole ◽  
James W. B. Moir
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Oxidase Activity ◽  
Rhodobacter Capsulatus ◽  
Resistance Mechanism ◽  
Growth Conditions ◽  
Anaerobic Conditions ◽  
No Removal ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

ABSTRACT Cytochrome c′ from Rhodobacter capsulatushas been shown to confer resistance to nitric oxide (NO). In this study, we demonstrated that the amount of cytochrome c′ synthesized for buffering of NO is insufficient to account for the resistance to NO but that the cytochrome-dependent resistance mechanism involves the catalytic breakdown of NO, under aerobic and anaerobic conditions. Even under aerobic conditions, the NO removal is independent of molecular oxygen, suggesting cytochrome c′ is a NO reductase. Indeed, we have measured the product of NO breakdown to be nitrous oxide (N2O), thus showing that cytochromec′ is behaving as a NO reductase. The increased resistance to NO conferred by cytochrome c′ is distinct from the NO reductase pathway that is involved in denitrification. Cytochromec′ is not required for denitrification, but it has a role in the removal of externally supplied NO. Cytochrome c′ synthesis occurs aerobically and anaerobically but is partly repressed under denitrifying growth conditions when other NO removal systems are operative. The inhibition of respiratory oxidase activity of R. capsulatus by NO suggests that one role for cytochromec′ is to maintain oxidase activity when both NO and O2 are present.

scholarly journals Low nitrous oxide production through nitrifier-denitrification in intermittent-feed high-rate nitritation reactors

2017 ◽  
Vol 123 ◽  
pp. 429-438 ◽  
Author(s):  
Qingxian Su ◽  
Chun Ma ◽  
Carlos Domingo-Félez ◽  
Anne Sofie Kiil ◽  
Bo Thamdrup ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
High Rate ◽  
Oxide Production ◽  
Nitrifier Denitrification ◽  
Nitrous Oxide Production
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