scholarly journals Electroenzymatic Nitrogen Fixation Using a MoFe Protein System Immobilized in an Organic Redox Polymer

2020 ◽  
Vol 59 (38) ◽  
pp. 16511-16516 ◽  
Author(s):  
Yoo Seok Lee ◽  
Adrian Ruff ◽  
Rong Cai ◽  
Koun Lim ◽  
Wolfgang Schuhmann ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Redox Polymer ◽  
Mofe Protein ◽  
Protein System

scholarly journals Nitrogenase Bioelectrocatalysis: ATP-Independent Ammonia Production Using a Redox Polymer/MoFe Protein System

ACS Catalysis ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 6854-6861 ◽  
Author(s):  
Yoo Seok Lee ◽  
Mengwei Yuan ◽  
Rong Cai ◽  
Koun Lim ◽  
Shelley D. Minteer
Keyword(s):  
Ammonia Production ◽  
Redox Polymer ◽  
Mofe Protein ◽  
Protein System

Biological nitrogen fixation: fundamentals

1982 ◽  
Vol 296 (1082) ◽  
pp. 375-385 ◽  
Keyword(s):  
Nitrogen Fixation ◽  
Klebsiella Pneumoniae ◽  
Biological Nitrogen Fixation ◽  
Mofe Protein ◽  
Fe Protein ◽  
Metal Contents ◽  
Physiological Constraint ◽  
Biological Nitrogen

The enzyme responsible for N 2 fixation, nitrogenase, is only found in prokaryotes. It consists of two metalloproteins, both irreversibly destroyed by exposure to the O 2 of air. The MoFe-protein binds N 2 and the Fe-protein, after activation by MgATP, supplies electrons. H 2 is evolved during the reduction of N 2 to NH 3 and can become the sole reaction in the absence of N 2 ; valuable information has been obtained by exploiting the ability of nitrogenase to reduce substrates such as acetylene, azides and cyanides. Substrate quantities of MgATP are required for all such reactions. The sensitivity of nitrogenase to oxygen is an important physiological constraint on its use and distribution; the ATP requirement and metal contents are less serious constraints. O 2 and NH 3 regulate synthesis and sometimes function of nitrogenase. Nitrogen fixation by Klebsiella pneumoniae is genetically encoded by 17 genes (the nif genes) in a cluster of seven or eight operons. The functions of several of these genes are known and the outlines of their regulation can be discerned. The nif cluster can be transferred to new prokaryotic genera, sometimes yielding new diazotrophic strains or species; they have been transferred to yeast and are silent. They have been cloned and alien DNA ( lac ) has been fused into nif Transfer of expressible nif to new genetic backgrounds has probably occurred in Nature and may be exploitable for agriculture.

scholarly journals Synthesis of Nitrogenase by Paenibacillus Sabinae T27 in Presence of High Levels of Ammonia During Anaerobic Fermentation

2020 ◽  
Author(s):  
Qin Li ◽  
Xiao-Juan He ◽  
Peng-Xi Liu ◽  
Hao-Wei Zhang ◽  
Ming-Yang Wang ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Anaerobic Fermentation ◽  
High Energy ◽  
Liquid Chromatography Mass Spectrometry ◽  
High Concentration ◽  
Qrt Pcr ◽  
Mofe Protein ◽  
Fe Protein ◽  
Nitrogenase Activities ◽  
Nitrogen Excess

Abstract BackgroundBiological nitrogen fixation catalyzed by nitrogenase is a high energy-intensive process, and thus nitrogenase synthesis and activity are inhibited by ammonium (NH4+). Microorganism fix nitrogen at high ammonium (30-300 mM) concentration has not been reported before.ResultsPaenibacillus sabinae T27, a Gram-positive, spore-forming diazotroph (N2-fixing microorganism, showed nitrogenase activities not only in low (0-4 mM) concentration of NH4+, but also in high (30-300 mM) concentration of NH4+, no matter whether the cells of this bacterium were grown in flask or in fermentor on scale cultivation. qRT-PCR and western blotting analysis supported that Fe protein and MoFe protein were synthesized under both low (0-4 mM) and high (30-300 mM) concentration of NH4+. Liquid chromatography-mass spectrometry（LC-MS）analysis revealed that MoFe protein purified form cultures grown in nitrogen-limited condition or nitrogen-excess condition was encoded by nifDK and Fe protein was encoded by both nifH and nifH2. The cross-reaction suggested the purified Fe and MoFe components from P. sabinae T27 grown in both nitrogen-limited and -excess conditions were active.ConclusionsOur results indicate that N2 fixation occurs in presence of high (30-300 mM) concentration of NH4+ in P. sabinae T27. Nitrogen fixation under both low and high concentration of NH4+ was catalyzed by the same nitrogenases and the Fe protein was encoded by both nifH and nifH2. Our study will provide a clue for studying the mechanisms on nitrogen fixation in presence of the high concentration of NH4+.

Factors controlling nitrogen fixation in temperate seagrass beds

2015 ◽  
Vol 525 ◽  
pp. 41-51 ◽  
Author(s):  
PLM Cook ◽  
V Evrard ◽  
RJ Woodland
Keyword(s):  
Nitrogen Fixation ◽  
Seagrass Beds

NEW CLOVER CULTIVARS FOR WAIKATO DAIRY PASTURE: ESTABLISHMENT, PRODUCTION AND NITROGEN FIXATION DURING THE FIRST YEAR

1988 ◽  
pp. 207-211
Author(s):  
S.F. Ledgard ◽  
G.J. Brier ◽  
R.N. Watson
Keyword(s):  
Nitrogen Fixation ◽  
White Clover ◽  
Dairy Cow ◽  
Red Clover ◽  
First Year ◽  
Buried Seed

Clover cultivars grown with ryegrass were compared in an establishment year under dairy cow grazing. There was no difference in total annual productton but summer production was greater with Pawera red clover and with Kopu or Pitau white clovers. Clovers differed little in the proportion of nitrogen fixed, except during summer when values were highest for Pawera. Pawera was less prone to nematode attack than white clover cultivars but was more susceptible to clover rot. Resident clovers and high buried seed levels (e.g., 11-91 kg/ha) made introduction of new clover cultivars difficult. Sown clovers established best (50-70% of total clover plants) when drilled into soil treated with dicamba and glyphosate. Keywords: white clover, red clover, nematodes. nitrogen fixation, pasture renovation

A Study on the Farmers’ Awareness and Acceptance of Biofertilizers in Kottayam District

GIS Business ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. 425-431
Author(s):  
Subin Thomas ◽  
Dr. M. Nandhini
Keyword(s):  
Organic Matter ◽  
Nitrogen Fixation ◽  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Nutrient Cycle ◽  
Plant Growth Promoting ◽  
Promote Plant Growth ◽  
Growth Promoting ◽  
Structured Questionnaire ◽  
Area Data

Biofertilizers are fertilizers containing microorganisms that promote plant growth by improving the supply of nutrients to the host plant. The supply of nutrients is improved naturally by nitrogen fixation and solubilizing phosphorus. The living microorganisms in biofertilizers help in building organic matter in the soil and restoring the natural nutrient cycle. Biofertilizers can be grouped into Nitrogen-fixing biofertilizers, Phosphorous-solubilizing biofertilizers, Phosphorous-mobilizing biofertilizers, Biofertilizers for micro nutrients and Plant growth promoting rhizobacteria. This study conducted in Kottayam district was intended to identify the awareness and acceptance of biofertilizers among the farmers of the area. Data have been collected from 120 farmers by direct interviews with structured questionnaire.

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