Denitrification by Cytophaga johnsonae strains and by a gliding bacterium able to reduce nitrous oxide in the presence of acetylene and sulfide

1986 ◽  
Vol 32 (5) ◽  
pp. 421-424 ◽  
Author(s):  
Anne M. Adkins ◽  
Roger Knowles
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Oxide ◽  
Electron Acceptors ◽  
Gliding Bacteria ◽  
Gliding Bacterium

A gliding bacterium (Is-11), isolated for its ability to reduce nitrous oxide (N2O) in the presence of acetylene (C2H2) and sulfide, was able to use nitrate (NO3−), nitrite (NO2−), and N2O as terminal electron acceptors for growth. Similarly, of five strains of Cytophaga johnsonae examined, two were capable of complete denitrification. Two strains were unable to reduce nitrate and N2O, respectively, and the remaining strain lacked both nitrate and N2O reductases. However, in this strain the N2O reductase was induced by the presence of nitrite, but not nitrate. Acetylene inhibited N2O reduction but did not affect the reduction of nitrite or nitrate in all of the gliding bacteria tested. Sulfide temporarily inhibited all of the nitrogen oxide reductases. It did not relieve the C2H2 inhibition of N2O reduction in the C. johnsonae strains when tested under the same conditions under which C2H2 inhibition is relieved in Is-11.

Identification of a denitrifying gliding bacterium, isolated from soil and able to reduce nitrous oxide in the presence of sulfide and acetylene, as Flexibacter canadensis

1990 ◽  
Vol 36 (11) ◽  
pp. 765-770 ◽  
Author(s):  
Alison M. Jones ◽  
Anne M. Adkins ◽  
Roger Knowles ◽  
Gina R. Rayat
Keyword(s):  
Nitrous Oxide ◽  
Key Words ◽  
Dna Hybridization ◽  
Inhibition Assay ◽  
Acetylene Inhibition ◽  
Biochemical Tests ◽  
Gliding Bacteria ◽  
Soil Isolate ◽  
Gliding Bacterium ◽  
Physiological And Biochemical

We have reexamined the properties of a gliding bacterium, Is-11, which was previously isolated from soil because of its ability to denitrify and to reduce nitrous oxide in the presence of sulfide and normally inhibitory concentrations of acetylene. Occurrence of such an organism may have important implications for the use of the acetylene inhibition assay for measuring denitrification rates in reduced, sulfidic environments. Although originally tentatively identified as a Cytophaga sp., extensive morphological, physiological, and biochemical tests as well as G+C analysis and DNA hybridization studies now indicate that the soil isolate Is-11 is a strain of Flexibacter canadensis. Key words: gliding bacteria, Flexibacter canadensis, denitrification, acetylene, sulfide, nitrous oxide.

Denitrifïcation in Flexibacter canadensis

1990 ◽  
Vol 36 (6) ◽  
pp. 430-434 ◽  
Author(s):  
Alison M. Jones ◽  
Roger Knowles
Keyword(s):  
Nitrous Oxide ◽  
Sodium Sulfide ◽  
Electron Acceptors ◽  
Inhibition Assay ◽  
Oxide Reduction ◽  
Acetylene Inhibition ◽  
Gram Negative ◽  
Nitrous Oxide Reduction ◽  
Pure Cultures ◽  
Gliding Bacterium

Denitrifïcation was studied in pure cultures of Flexibacter canadensis (ATCC 29591), a Gram-negative gliding bacterium found in soil. Flexibacter canadensis was capable of using nitrate, nitrite, and nitrous oxide as terminal electron acceptors for growth. Sodium sulfide (200 μM) inhibited all of the nitrogen oxide reductases, but only temporarily. Acetylene (4 kPa) inhibited nitrous oxide reduction but did not affect the reduction of either nitrate or nitrite. However, sulfide (100 and 200 μM) alleviated the acetylene block and permitted reduction of nitrous oxide in the presence of 4 kPa acetylene. These data may have important implications regarding the use of the acetylene inhibition assay for measuring denitrifïcation rates in highly anaerobic, sulfidic environments. Key words: Flexibacter canadensis, denitrification, N2O reductase, sulfide, acetylene.

Effect of sulfur dioxide removal by limestone on nitrogen oxide (NOx) and nitrous oxide emissions from a circulating fluidized bed combustor

1992 ◽  
Vol 6 (6) ◽  
pp. 753-757 ◽  
Author(s):  
Tadaaki Shimizu ◽  
Yutaka Tachiyama ◽  
Daisuke Fujita ◽  
Kenichi Kumazawa ◽  
Osamu Wakayama ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Sulfur Dioxide ◽  
Nitrogen Oxide ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Nitrous Oxide Emissions ◽  
Sulfur Dioxide Removal ◽  
Fluidized Bed Combustor

Negative chemotaxis in Cytophaga johnsonae

1996 ◽  
Vol 42 (5) ◽  
pp. 515-518 ◽  
Author(s):  
Zheng-Xian Liu ◽  
Irwin Fridovich
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Salmonella Typhimurium ◽  
Nalidixic Acid ◽  
Sodium Phosphate ◽  
Low Ph ◽  
Chemotactic Response ◽  
High Ph ◽  
Gliding Bacteria ◽  
Gliding Bacterium

Chemotaxis, both positive and negative, has been extensively studied in flagellated bacteria, such as Escherichia coli and Salmonella typhimurium, but not in gliding bacteria. The rapidly motile gliding bacterium Cytophaga johnsonae has been seen to be repelled by H2O2, OCl−, and N-chlorotaurine, as well as by low pH. Its response to H2O2 was eliminated by catalase. Nalidixic acid at 200 μM, which inhibits the growth but not the motility of C. johnsonae, did not interfere with its negative chemotactic response to H2O2, whereas sodium phosphate at 10 mM, which inhibits motility, did so. Cytophaga johnsonae was not repelled by taurine, n-octanol, phenol, L-valine, or high pH. Chemotaxis can be conveniently studied in gliding bacteria such as C. johnsonae.Key words: gliding bacteria, Cytophaga johnsonae, negative chemotaxis, hydrogen peroxide, N-chlorotaurine.

scholarly journals Denitrification kinetics indicates nitrous oxide uptake is unaffected by electron competition in Accumulibacter

2020 ◽  
Author(s):  
Roy Samarpita ◽  
Pradhan Nirakar ◽  
NG How Yong ◽  
Wuertz Stefan
Keyword(s):  
Nitrous Oxide ◽  
Electron Acceptor ◽  
Phosphorus Removal ◽  
Metabolic Model ◽  
Electron Acceptors ◽  
Treatment Technology ◽  
Denitrifying Phosphorus Removal ◽  
Terminal Electron Acceptor ◽  
Efficient Treatment ◽  
Denitrification Kinetics

ABSTRACTDenitrifying phosphorus removal is a cost and energy efficient treatment technology that relies on polyphosphate accumulating organisms (DPAOs) utilizing nitrate or nitrite as terminal electron acceptor. Denitrification is a multistep process and many organisms do not possess the complete pathway, leading to the accumulation of intermediates such as nitrous oxide (N2O), a potent greenhouse gas and ozone depleting substance. Candidatus Accumulibacter organisms are prevalent in denitrifying phosphorus removal processes and, according to genomic analyses, appear to vary in their denitrification abilities based on their lineage. Yet, denitrification kinetics and nitrous oxide accumulation by Accumulibacter after long-term exposure to either nitrate or nitrite as electron acceptor have never been compared. We investigated the preferential use of the nitrogen oxides involved in denitrification and nitrous oxide accumulation in two enrichments of Accumulibacter and a competitor – the glycogen accumulating organism Candidatus Competibacter. A metabolic model was modified to predict phosphorus removal and denitrification rates when nitrate, nitrite or N2O were added as electron acceptors in different combinations. Unlike previous studies, no N2O accumulation was observed for Accumulibacter in the presence of multiple electron acceptors. Electron competition did not affect denitrification kinetics or N2O accumulation in Accumulibacter or Competibacter. Despite the presence of sufficient internal storage polymers (polyhydroxyalkanoates, or PHA) as energy source for each denitrification step, the extent of denitrification observed was dependent on the dominant organism in the enrichment. Accumulibacter showed complete denitrification and N2O utilization, whereas for Competibacter denitrification was limited to reduction of nitrate to nitrite. These findings indicate that DPAOs can contribute to lowering N2O emissions in the presence of multiple electron acceptors under partial nitritation conditions.

scholarly journals Influence of the exchanged metal ions (Cu, Co, Ni and Mn) on the selective catalytic reduction of NO with hydrocarbons over modified ferrierite

2013 ◽  
Vol 15 (2) ◽  
pp. 10-15 ◽  
Author(s):  
Wiesława Ćwikla-Bundyra
Keyword(s):  
Nitrous Oxide ◽  
Ion Exchange ◽  
Nitrogen Oxide ◽  
Natural Zeolite ◽  
No Reduction ◽  
Catalytic Properties ◽  
Catalytic Reduction ◽  
Reduction Of No ◽  
Metal Contents ◽  
Cobalt Species

This article presents the research results concerning the possibilities of natural zeolite-ferrierite application for the reduction of nitrogen oxide. H-FER forms were modified by Cu+2, Co+2, Mn+2, Ni+2 using an ion exchange procedure. The effect of metal contents was shown for the ferrierite matrices and related to their catalytic properties. The catalytic properties of Cu-, Co-Ni-, and Mn- were compared for NO reduction with methane. High NO conversion was observed for copper and cobalt-ferrierite catalysts, especially in the temperature range 400 and 500oC. It was found that copper- and cobalt-ferrierite catalysts have higher activity and N2 selectivity than the catalysts composed of nickel and manganese doped on ferrierite. Moreover, the nickel and manganese containing catalysts produced more nitrous oxide than nitrogen. The presence of both copper and cobalt species seems to be an indispensable condition for a large activity and selectivity in the NO reduction.

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