Membrane-associated, dissimilatory nitrite reductase of the denitrifying fungus Cylindrocarpon tonkinense

1999 ◽  
Vol 171 (3) ◽  
pp. 210-213 ◽  
Author(s):  
Yuko Kubota ◽  
Naoki Takaya ◽  
H. Shoun
Keyword(s):  
Nitrite Reductase ◽  
Dissimilatory Nitrite Reductase ◽  
Cylindrocarpon Tonkinense

Purification and Characterization of a Dissimilatory Nitrite Reductase from the Phototrophic Bacterium Rhodopseudomonas palustris

1983 ◽  
Vol 38 (11-12) ◽  
pp. 933-938 ◽  
Author(s):  
Michaela Preuß ◽  
Jobst-Heinrich Klemme
Keyword(s):  
Cytochrome C ◽  
Nitrite Reductase ◽  
Rhodopseudomonas Palustris ◽  
Gel Filtration ◽  
Enzyme Synthesis ◽  
Nitrite Reduction ◽  
Phototrophic Bacterium ◽  
Dissimilatory Nitrite Reductase ◽  
Basic Level

A dissimilatory nitrite reductase from the facultatively phototrophic bacterium , Rhodopseudomonas palustris strain 1a1 was studied. A basic level of the enzyme (10 -50 mU/mg protein) was measured in dark, aerated and anaerobic, photosynthetic cultures. A marked derepression of enzyme synthesis occurred under conditions of oxygen limitation (200-300 mU/mg protein). The addition of nitrite (or nitrate) to the culture medium had only a slight effect on the maximal nitrite reductase titer of cells. The enzyme was purified from photosynthetically grown cells by precipitation with ammonium sulfate, gel filtration through Sepharose 6B and repeated chromatography on DE 52-cellulose. As estimated by gel filtration, the nitrite reductase had a molecular weight of about 120 000 ± 12 000 and yielded only one band (mol. wt. of about 68 000 ± 7000) in SDS-gel electrophoresis. The isoelectric point of the enzyme was at pH 5.1. Nitric oxide (NO) was identified as the reaction product of nitrite reduction. The enzyme also exhibited cytochrome c-oxidase activity and was active with chemically reduced viologen dyes, FMN and cytochrome c as electron donors. Highly purified nitrite reductase preparations contained 10 mol% of a c-type cytochrome. Trace metal analyses indicated the presence of Cu in the enzyme. Consistent with the detection of Cu was the finding that the Cu-chelator, diethyldithiocarbamate, strongly inhibited the nitrite reductase

scholarly journals Dissimilatory Nitrite Reductase Genes from Autotrophic Ammonia-Oxidizing Bacteria

2001 ◽  
Vol 67 (5) ◽  
pp. 2213-2221 ◽  
Author(s):  
Karen L. Casciotti ◽  
Bess B. Ward
Keyword(s):  
Nitrite Reductase ◽  
Sequence Data ◽  
Pcr Primers ◽  
Nitrite Reduction ◽  
Nitrifying Bacteria ◽  
Ammonia Oxidizing Bacteria ◽  
Significant Similarity ◽  
Nitrite Reductase Gene ◽  
Reductase Gene ◽  
Dissimilatory Nitrite Reductase

ABSTRACT The presence of a copper-containing dissimilatory nitrite reductase gene (nirK) was discovered in several isolates of β-subdivision ammonia-oxidizing bacteria using PCR and DNA sequencing. PCR primers Cunir3 and Cunir4 were designed based on published nirK sequences from denitrifying bacteria and used to amplify a 540-bp fragment of the nirK gene fromNitrosomonas marina and five additional isolates of ammonia-oxidizing bacteria. Amplification products of the expected size were cloned and sequenced. Alignment of the nucleic acid and deduced amino acid (AA) sequences shows significant similarity (62 to 75% DNA, 58 to 76% AA) between nitrite reductases present in these nitrifiers and the copper-containing nitrite reductase found in classic heterotrophic denitrifiers. While the presence of a nitrite reductase in Nitrosomonas europaea is known from early biochemical work, preliminary sequence data from its genome indicate a rather low similarity to the denitrifier nirKs. Phylogenetic analysis of the partial nitrifier nirK sequences indicates that the topology of the nirK tree corresponds to the 16S rRNA andamoA trees. While the role of nitrite reduction in the metabolism of nitrifying bacteria is still uncertain, these data show that the nirK gene is present in closely related nitrifying isolates from many oceanographic regions and suggest thatnirK sequences retrieved from the environment may include sequences from ammonia-oxidizing bacteria.

Crystallization and preliminary X-ray crystallographic studies of dissimilatory nitrite reductase isolated fromHyphomicrobium denitrificansA3151

2004 ◽  
Vol 60 (12) ◽  
pp. 2383-2386
Author(s):  
Yong Xie ◽  
Tsuyoshi Inoue ◽  
Nozomu Seike ◽  
Hiroyoshi Matsumura ◽  
Koji Kanbayashi ◽  
...  
Keyword(s):  
Nitrite Reductase ◽  
X Ray ◽  
Dissimilatory Nitrite Reductase

scholarly journals Purification, Characterization, and Genetic Analysis of Cu-Containing Dissimilatory Nitrite Reductase from a Denitrifying Halophilic Archaeon, Haloarcula marismortui

2001 ◽  
Vol 183 (14) ◽  
pp. 4149-4156 ◽  
Author(s):  
Hirotaka Ichiki ◽  
Yoko Tanaka ◽  
Kiyotaka Mochizuki ◽  
Katsuhiko Yoshimatsu ◽  
Takeshi Sakurai ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Nitrite Reductase ◽  
Sodium Dodecyl ◽  
Resonance Spectroscopy ◽  
Halophilic Archaeon ◽  
Haloarcula Marismortui ◽  
Dissimilatory Nitrite Reductase

ABSTRACT Cu-containing dissimilatory nitrite reductase (CuNiR) was purified from denitrifying cells of a halophilic archaeon, Haloarcula marismortui. The purified CuNiR appeared blue in the oxidized state, possessing absorption peaks at 600 and 465 nm in the visible region. Electron paramagnetic resonance spectroscopy suggested the presence of type 1 Cu (gII = 2.232; AII = 4.4 mT) and type 2 Cu centers (gII = 2.304; AII = 13.3 mT) in the enzyme. The enzyme contained two subunits, whose apparent molecular masses were 46 and 42 kDa, according to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. N-terminal amino acid sequence analysis indicated that the two subunits were identical, except that the 46-kDa subunit was 16 amino acid residues longer than the 42-kDa subunit in the N-terminal region. A nirK gene encoding the CuNiR was cloned and sequenced, and the deduced amino acid sequence with a residual length of 361 amino acids was homologous (30 to 41%) with bacterial counterparts. Cu-liganding residues His-133, Cys-174, His-182, and Met-187 (for type 1 Cu) and His-138, His-173, and His-332 (for type 2 Cu) were conserved in the enzyme. As generally observed in the halobacterial enzymes, the enzymatic activity of the purified CuNiR was enhanced during increasing salt concentration and reached its maximum in the presence of 2 M NaCl with the value of 960 μM NO2 − · min−1 · mg−1.

Denitrification within the genus Azospirillum and other associative bacteria

2001 ◽  
Vol 28 (9) ◽  
pp. 991 ◽  
Author(s):  
Karin Kloos ◽  
Alexander Mergel ◽  
Christopher Rösch ◽  
Hermann Bothe
Keyword(s):  
Nitrite Reductase ◽  
Plant Growth Promoting Rhizobacteria ◽  
Selective Advantage ◽  
Molecular Data ◽  
Associative Bacteria ◽  
Activity Measurements ◽  
Plant Growth Promoting ◽  
Cytochrome Cd1 ◽  
Polymerase Chain ◽  
Dissimilatory Nitrite Reductase

This paper originates from an address at the 8th International Symposium on Nitrogen Fixation with Non-Legumes, Sydney, NSW, December 2000 Different Azospirillumstrains and some other plant growth-promoting rhizobacteria (PGPR) were screened for the occurrence of genes coding for denitrification and nitrogenase reductase (nifH) using polymerase chain reaction (PCR)-based techniques. All PGPR examined were nitrogenase-positive. Azospirillum strains were remarkably dissimilar with respect to denitrification capabilities, in particular with respect to genes of the dissimilatory nitrite reductase. A. brasilense, A. lipoferum and A. halopraeferens strains possess a cytochrome cd1-containing nitrite reductase with low sequence similarities among them. A. irakense and A. doebereinerae have a Cu-containing nitrite reductase and A. amazonense is unable to denitrify. The molecular data were corroborated by activity measurements. The current results indicate that the inability to perform denitrification is unlikely a selective advantage for Azospirillum spp. and other associative bacteria for forming an association with plant roots.

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