Nitrate reduction and nitrogenase activity in Spirillum lipoferum

1977 ◽  
Vol 23 (3) ◽  
pp. 306-310 ◽  
Author(s):  
Carlos A. Neyra ◽  
Peter Van Berkum
Keyword(s):  
Nitrate Reduction ◽  
Time Course ◽  
Nitrogenase Activity ◽  
Reductase Activity ◽  
Nitrite Reduction ◽  
Lag Phase ◽  
Nitrite Accumulation ◽  
Assimilatory Nitrate Reduction ◽  
Nitrate And Nitrite ◽  
Anaerobic Pretreatment

Nitrate and nitrite reduction under aerobic, microaerophillic, and anaerobic conditions was demonstrated in Spirillum lipoferum (ATCC 29145). Nitrite did not accumulate during assimilatory nitrate reduction in air. The nitrite produced during dissimilatory nitrate reduction accumulated in the medium but not in the cells. On exposure of the bacteria to nitrate and anaerobiosis, a low initial rate (lag) was followed by accelerated rates of nitrite accumulation. A 3-h anaerobic pretreatment, in the absence of nitrate, did not avoid the lag phase. No nitrate reductase activity (NRA) developed in the presence of chloramphenicol. The data suggest that induction of anaerobic NRA in S. lipoferum required nitrate and protein synthesis.Anaerobic N2ase activity by S. lipoferum was greatly stimulated in the presence of nitrate. The time course of nitrate reduction was coincidental with the pattern of nitrate-stimulated N2ase activity indicating that a relationship exists between these two processes.

scholarly journals Glycerol-driven Denitratation: Process Kinetics, Microbial Ecology, and Operational Controls

2021 ◽  
Author(s):  
Matthew P. Baideme ◽  
Chenghua Long ◽  
Luke T. Plante ◽  
Jeffrey A. Starke ◽  
Michael A. Butkus ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Microbial Ecology ◽  
Nitrate Reduction ◽  
Carbon Sources ◽  
Selective Reduction ◽  
Nitrite Reduction ◽  
Nitrite Accumulation ◽  
Ammonium Oxidation ◽  
Order Of Magnitude ◽  
Nitrate And Nitrite

ABSTRACTDenitratation, the selective reduction of nitrate to nitrite, is a novel process when coupled with anaerobic ammonium oxidation (anammox) could achieve resource-efficient biological nitrogen removal of ammonium- and nitrate-laden waste streams. Using a fundamentally-based, first principles approach, this study optimized a stoichiometrically-limited, glycerol-driven denitratation process and characterized mechanisms supporting nitrite accumulation with results that aligned with expectations. Glycerol supported selective nitrate reduction to nitrite and near-complete nitrate conversion, indicating its viability in a denitratation system. Glycerol-supported specific rates of nitrate reduction (135.3 mg-N/g-VSS/h) were at least one order of magnitude greater than specific rates of nitrite reduction (14.9 mg-N/g-VSS/h), potentially resulting in transient nitrite accumulation and indicating glycerol’s superiority over other organic carbon sources in denitratation systems. pH and ORP inflection points in nitrogen transformation assays corresponded to maximum nitrite accumulation, indicating operational setpoints to prevent further nitrite reduction. Denitratation conditions supported enrichment of Thauera sp. as the dominant genus. Stoichiometric limitation of influent organic carbon, coupled with differential nitrate and nitrite reduction kinetics, optimized operational controls, and a distinctively enriched microbial ecology, was identified as causal in glycerol-driven denitratation.

Effect of Herbicides on In Vivo Nitrate and Nitrite Reduction

Weed Science ◽  
1977 ◽  
Vol 25 (1) ◽  
pp. 18-22 ◽  
Author(s):  
R.L. Finke ◽  
R.L. Warner ◽  
T.J. Muzik
Keyword(s):  
Hordeum Vulgare ◽  
Nitrate Reductase ◽  
Nitrate Reduction ◽  
Amaranthus Retroflexus ◽  
Nitrite Reduction ◽  
Nitrite Accumulation ◽  
Inhibitory Effects ◽  
Potassium Azide ◽  
Nitrate And Nitrite

The effects of herbicides on in vivo nitrate and nitrite reduction were determined by vacuum infiltrating sections of barley (Hordeum vulgareL.) or bean (Phaseolus vulgarisL.) leaves with solutions containing nitrate and herbicides. Herbicides causing a reduction of nitrite accumulation in the dark were considered to have inhibitory effects upon nitrate reduction and those causing an accumulation of nitrite in the light were considered to inhibit nitrite reduction. Only dinoseb (2-sec-butyl-4,6-dinitrophenol) and potassium azide significantly reduced nitrate reduction in both barley and bean. All of the herbicides which inhibit photosynthesis inhibited nitrite reduction but had no significant effect on nitrate reduction in barley and bean. Nitrite reduction in an atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] resistant pigweed (Amaranthus retroflexusL.) biotype was not affected by any triazine tested. However, these triazines significantly inhibited nitrite reduction in barley, bean, and the susceptible pigweed biotype. The results suggest that the in vivo nitrate reductase technique may be a useful technique for identifying chemicals which inhibit the flow of electrons to ferredoxin, thereby inhibiting nitrite reduction in light.

Effects of pH and alkalinity on sulfur-denitrification in a biological granular filter

1996 ◽  
Vol 34 (1-2) ◽  
pp. 355-362 ◽  
Author(s):  
Hiroaki Furumai ◽  
Hideki Tagui ◽  
Kenji Fujita
Keyword(s):  
Enrichment Culture ◽  
Nitrite Reduction ◽  
The Other ◽  
Nitrite Accumulation ◽  
Ph Dependency ◽  
Effects Of Ph ◽  
Rapid Removal ◽  
Nitrate And Nitrite ◽  
The Relationship ◽  
Biological Filters

Two laboratory-scale biological filters were operated to investigate the effects of alkalinity and pH on removal of nitrate and nitrite in sulfur denitrification filter processes. The concentration of sodium bicarbonate in the feed media was changed from 120 to 240 mg/l during about 3 months in a filter (Run A). The other filter was initially fed with 300 mg/l and then with 240 mg/l (Run B). The performance of the filter was monitored by measuring pH, nitrate, nitrite, sulfate, alkalinity, and thiosulfate. Nitrate concentration in effluent rapidly decreased to lower levels within several days for both filters after inoculation of enrichment culture of sulfur denitrifiers. However there was a large difference in removal of nitrite. When rapid removal of nitrate took place, nitrite accumulation was observed and remained while the bicarbonate concentration was 120 and 150 mg/l. On the other hand the nitrite accumulation disappeared when more bicarbonate (240 and 300 mg/l) was supplied. The experimental results indicated that the nitrite accumulation was closely related to pH condition and alkalinity level in the filter. The stable data of effluent water quality for 5 cases were collected and the relationship discussed between nitrite concentration and pH in effluents. The relationship indicated a strong pH dependency on nitrite accumulation below pH of 7.4. The pH condition around 7 is not so inhibitory to biological activity. Therefore, the pH within the biofilm would be low enough to suppress the nitrite reduction by sulfur denitrifiers, while the pH in effluent was not in the inhibitory range. It was recommended to keep the pH higher than 7.4 to prevent nitrite accumulation in the sulfur denitrification filter.

scholarly journals Biogenic Fe(II-III) Hydroxycarbonate Green Rust Enhances Nitrate Removal and Decreases Ammonium Selectivity during Heterotrophic Denitrification

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 818
Author(s):  
Georges Ona-Nguema ◽  
Delphine Guerbois ◽  
Céline Pallud ◽  
Jessica Brest ◽  
Mustapha Abdelmoula ◽  
...  
Keyword(s):  
Nitrate Reduction ◽  
Nitrate Removal ◽  
Green Rust ◽  
Nitrite Reduction ◽  
Nitrite Accumulation ◽  
Bacterial Reduction ◽  
Water Treatment Process ◽  
Nitrite Production ◽  
Ammonium Production ◽  
Biogenic Iron

Nitrification-denitrification is the most widely used nitrogen removal process in wastewater treatment. However, this process can lead to undesirable nitrite accumulation and subsequent ammonium production. Biogenic Fe(II-III) hydroxycarbonate green rust has recently emerged as a candidate to reduce nitrite without ammonium production under abiotic conditions. The present study investigated whether biogenic iron(II-III) hydroxycarbonate green rust could also reduce nitrite to gaseous nitrogen during bacterial nitrate reduction. Our results showed that biogenic iron(II-III) hydroxycarbonate green rust could efficiently decrease the selectivity of the reaction towards ammonium during heterotrophic nitrate reduction by native wastewater-denitrifying bacteria and by three different species of Shewanella: S. putrefaciens ATCC 12099, S. putrefaciens ATCC 8071 and S. oneidensis MR-1. Indeed, in the absence of biogenic hydroxycarbonate green rust, bacterial reduction of nitrate converted 11–42% of the initial nitrate into ammonium, but this value dropped to 1–28% in the presence of biogenic hydroxycarbonate green rust. Additionally, nitrite accumulation did not exceed the 2–13% in the presence of biogenic hydroxycarbonate green rust, versus 0–28% in its absence. Based on those results that enhance the extent of denitrification of about 60%, the study proposes a water treatment process that couples the bacterial nitrite production with the abiotic nitrite reduction by biogenic green rust.

scholarly journals Implications of Limited Thermophilicity of Nitrite Reduction for Control of Sulfide Production in Oil Reservoirs

2016 ◽  
Vol 82 (14) ◽  
pp. 4190-4199 ◽  
Author(s):  
Tekle Tafese Fida ◽  
Chuan Chen ◽  
Gloria Okpala ◽  
Gerrit Voordouw
Keyword(s):  
Nitrate Reduction ◽  
Nitrite Reduction ◽  
Oil Fields ◽  
Microbial Consortia ◽  
Subsequent Reduction ◽  
Content Type ◽  
Reduction Activity ◽  
Pure Cultures ◽  
Nitrate And Nitrite ◽  
Reducing Bacteria

ABSTRACTNitrate reduction to nitrite in oil fields appears to be more thermophilic than the subsequent reduction of nitrite. Concentrated microbial consortia from oil fields reduced both nitrate and nitrite at 40 and 45°C but only nitrate at and above 50°C. The abundance of thenirSgene correlated with mesophilic nitrite reduction activity.ThaueraandPseudomonaswere the dominant mesophilic nitrate-reducing bacteria (mNRB), whereasPetrobacterandGeobacilluswere the dominant thermophilic NRB (tNRB) in these consortia. The mNRBThauerasp. strain TK001, isolated in this study, reduced nitrate and nitrite at 40 and 45°C but not at 50°C, whereas the tNRBPetrobactersp. strain TK002 andGeobacillussp. strain TK003 reduced nitrate to nitrite but did not reduce nitrite further from 50 to 70°C. Testing of 12 deposited pure cultures of tNRB with 4 electron donors indicated reduction of nitrate in 40 of 48 and reduction of nitrite in only 9 of 48 incubations. Nitrate is injected into high-temperature oil fields to prevent sulfide formation (souring) by sulfate-reducing bacteria (SRB), which are strongly inhibited by nitrite. Injection of cold seawater to produce oil creates mesothermic zones. Our results suggest that preventing the temperature of these zones from dropping below 50°C will limit the reduction of nitrite, allowing more effective souring control.IMPORTANCENitrite can accumulate at temperatures of 50 to 70°C, because nitrate reduction extends to higher temperatures than the subsequent reduction of nitrite. This is important for understanding the fundamentals of thermophilicity and for the control of souring in oil fields catalyzed by SRB, which are strongly inhibited by nitrite.

scholarly journals Regulation of nap Gene Expression and Periplasmic Nitrate Reductase Activity in the Phototrophic Bacterium Rhodobacter sphaeroides DSM158

2002 ◽  
Vol 184 (6) ◽  
pp. 1693-1702 ◽  
Author(s):  
Mónica Gavira ◽  
M. Dolores Roldán ◽  
Francisco Castillo ◽  
Conrado Moreno-Vivián
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Nitrate Reduction ◽  
Reductase Activity ◽  
Enzyme Activation ◽  
Nitrite Accumulation ◽  
Northern Blots ◽  
Reverse Transcription Pcr ◽  
Phototrophic Growth ◽  
Very High

ABSTRACT Bacterial periplasmic nitrate reductases (Nap) can play different physiological roles and are expressed under different conditions depending on the organism. Rhodobacter sphaeroides DSM158 has a Nap system, encoded by the napKEFDABC gene cluster, but nitrite formed is not further reduced because this strain lacks nitrite reductase. Nap activity increases in the presence of nitrate and oxygen but is unaffected by ammonium. Reverse transcription-PCR and Northern blots demonstrated that the napKEFDABC genes constitute an operon transcribed as a single 5.5-kb product. Northern blots and nap-lacZ fusions revealed that nap expression is threefold higher under aerobic conditions but is regulated by neither nitrate nor ammonium, although it is weakly induced by nitrite. On the other hand, nitrate but not nitrite causes a rapid enzyme activation, explaining the higher Nap activity found in nitrate-grown cells. Translational nap′-′lacZ fusions reveal that the napK and napD genes are not efficiently translated, probably due to mRNA secondary structures occluding the translation initiation sites of these genes. Neither butyrate nor caproate increases nap expression, although cells growing phototrophically on these reduced substrates show a very high Nap activity in vivo (nitrite accumulation is sevenfold higher than in medium with malate). Phototrophic growth on butyrate or caproate medium is severely reduced in the NapA− mutants. Taken together, these results indicate that nitrate reduction in R. sphaeroides is mainly regulated at the level of enzyme activity by both nitrate and electron supply and confirm that the Nap system is involved in redox balancing using nitrate as an ancillary oxidant to dissipate excess reductant.

scholarly journals Nitrate reduction and nitrogen fixation in symbiotic association Rhizobium-legumes.

2002 ◽  
Vol 49 (2) ◽  
pp. 537-546 ◽  
Author(s):  
Robert Luciński ◽  
Władysław Polcyn ◽  
Lech Ratajczak
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reduction ◽  
Nitrogenase Activity ◽  
Reductase Activity ◽  
Gas Diffusion ◽  
Review Literature ◽  
Diffusion Resistance ◽  
Symbiotic Association ◽  
Symbiotic Associations ◽  
Legume Plants

The inhibitory effect of nitrate on nitrogenase activity in root nodules of legume plants has been known for a long time. The major factor inducing changes in nitrogenase activity is the concentration of free oxygen inside nodules. Oxygen availability in the infected zone of nodule is limited, among others, by the gas diffusion resistance in nodule cortex. The presence of nitrate may cause changes in the resistance to O2 diffusion. The aim of this paper is to review literature data concerning the effect of nitrate on the symbiotic association between rhizobia and legume plants, with special emphasis on nitrogenase activity. Recent advances indicate that symbiotic associations of Rhizobium strains characterized by a high nitrate reductase activity are less susceptible to inhibition by nitrate. A thesis may be put forward that dissimilatory nitrate reduction, catalyzed by bacteroid nitrate reductase, significantly facilitates the symbiotic function of bacteroids.

scholarly journals Light-Mediated Nitrite Accumulation during Denitrification by Pseudomonas sp. Strain JR12

1998 ◽  
Vol 64 (3) ◽  
pp. 813-817 ◽  
Author(s):  
Yoram Barak ◽  
Yossi Tal ◽  
Jaap van Rijn
Keyword(s):  
Nitrate Reduction ◽  
Electron Flow ◽  
Inhibitory Effect ◽  
Nitrite Reduction ◽  
Aerobic Respiration ◽  
Nitrite Accumulation ◽  
Respiratory Pathway ◽  
Low Light ◽  
Light Inhibition ◽  
Effect Of Light

ABSTRACT The effect of light on the denitrifying characteristics of a nonphotosynthetic denitrifier, Pseudomonas sp. strain JR12, was examined. Already at low light intensities, nitrite accumulated as a result of light inhibition of nitrite but not of nitrate reduction rates. Exposure of this bacterium to light caused a photooxidation of cytochrome c, an intermediate electron carrier in its respiratory pathway. Photoinhibition of nitrite reduction was reversible, as nitrite reduction rates returned to preillumination levels when light-exposed cells were returned to dark conditions. Antimycin A reversed the inhibitory effect of light on nitrite reduction by preventing a reversed electron flow. Aerobic respiration by this bacterium was not affected by light.

scholarly journals Isotopic fractionation associated to nitrate attenuation by ferrous iron containing minerals

2019 ◽  
Vol 98 ◽  
pp. 12013
Author(s):  
Rosanna Margalef-Marti ◽  
Raul Carrey ◽  
Albert Soler ◽  
Neus Otero
Keyword(s):  
Nitrate Reduction ◽  
Ferrous Iron ◽  
Laboratory Experiments ◽  
Isotopic Fractionation ◽  
Rapid Decrease ◽  
Nitrite Reduction ◽  
N2o Production ◽  
Preliminary Results ◽  
Nitrate And Nitrite ◽  
N Compounds

Biotic and abiotic laboratory experiments of nitrate and nitrite reduction by Fe-containing minerals were performed and the isotopic fractionation of the different reactions was calculated in order to determine whether it is possible to distinguish biotic and abiotic reactions involving N compounds. Results of biotic experiments showed nitrate reduction up to 96 % with transient NO2- accumulation and no significant N2O production. No significant nitrate attenuation was observed in abiotic nitrate reduction experiments. Abiotic experiments of nitrite reduction showed a rapid decrease in nitrite concentrations in those experiments with added Fe2+ coupled with a significant N2O production. Preliminary results of the N and O isotopic fractionation of the biotic experiments of nitrate reduction show differences in the ε15NNO3 and ε18ONO3 when different minerals were added. The abiotic experiments of nitrite reduction contrarily, showed similar ε15NNO2 in all the experiments.

EFFECT OF ACCLIMATION TO HIGH NITRATE INTAKES ON SOME RUMEN FERMENTATION PARAMETERS IN SHEEP

1985 ◽  
Vol 65 (4) ◽  
pp. 841-849 ◽  
Author(s):  
A. R. ALABOUDI ◽  
G. A. JONES
Keyword(s):  
Nitrate Reduction ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Residual Effect ◽  
Basal Diet ◽  
Rumen Fermentation ◽  
Nitrite Reduction ◽  
Rumen Bacteria ◽  
Cereal Grain ◽  
Nitrate And Nitrite

Four sheep, fed a basal diet which included 44% cereal grain and 50% hay and which was supplemented with KNO3, were progressively acclimated to a KNO3 intake of 2.5 g∙kg body wt−1∙day−1. Nitrate and nitrite reducing activity in strained rumen fluid (SRF) collected 2 h after feeding showed maximum values of 45.3 μg N∙mL−1∙h−1 and 39.4 μg N∙mL−1∙h−1, respectively, at an intake of 1.5 g∙kg body wt−1∙day−1. The rate of nitrate reduction was threefold higher (P < 0.01), and that of nitrite reduction fivefold higher (P < 0.01), than in SRF from sheep not receiving KNO3. When the KNO3 supplement was withdrawn the reducing activities fell to their initial levels within 3 wk. In a second experiment, nitrate, nitrite and volatile fatty acids in SRF, and methemoglobin in peripheral blood, were estimated at 30-min intervals after feeding in four sheep, two of which received 1.5 g KNO3∙kg body wt−1∙day−1. In the animals fed KNO3 the peak concentration of nitrate in SRF (13.30 μg NO3−–N∙mL−1) was reached 30 min after feeding, and that of nitrite (2.90 μg NO2−–N∙mL−1) 60 min after feeding; the presence of nitrate in SRF was associated with an increase in the molar proportion of acetate (P < 0.01) and a decrease in the proportion of n-butyrate (P < 0.01). The blood methemoglobin concentration did not exceed 2% (wt/wt) of total hemoglobin at any sampling time. In these animals 30–35 g KNO3 cleared the rumen within 3 h after feeding with no symptoms of nitrate toxicity. Enumeration of rumen bacteria by a direct isolation procedure indicated that the proportion of nitrate reducers in SRF was threefold higher (P < 0.01) in acclimated animals than in control animals. It was concluded that safe acclimation of sheep to high levels of dietary nitrate involved an increase in the rates of nitrate and nitrite reduction in the rumen, a narrowing of the ratio of these activities, and an increase in the proportion of nitrate reducing rumen bacteria. The residual effect of nitrate on the fermentation following clearance from the rumen was short-lived. Key words: Rumen fermentation, sheep, nitrate toxicity, nitrate reduction, nitrite reduction, rumen bacteria

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