Guntur Venkata Subbarao

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Regulating nitrification could be a key strategy in improving nitrogen (N) recovery and agronomic N-use efficiency in situations where the loss of N following nitrification is significant. A highly sensitive bioassay using recombinant luminescent Nitrosomonas europaea, has been developed that can detect and quantify the amount of nitrification inhibitors(More)
A bioluminescence assay using recombinant Nitrosomonas europaea was adopted to detect and quantify natural nitrification inhibitors in plant–soil systems. The recombinant strain of N. europaea produces a distinct two-peak luminescence due to the expression of luxAB genes, introduced from Vibrio harveyi, during nitrification. The bioluminescence produced in(More)
Using a recombinant luminescent Nitrosomonas europaea assay to quantify biological nitrification inhibition (BNI), we found that a wild relative of wheat (Leymus racemosus (Lam.) Tzvelev) had a high BNI capacity and releases about 20 times more BNI compounds (about 30 ATU g−1 root dry weight 24 h−1) than Triticum aestivum L. (cultivated wheat). The root(More)
Nitrification results in poor nitrogen (N) recovery and negative environmental impacts in most agricultural systems. Some plant species release secondary metabolites from their roots that inhibit nitrification, a phenomenon known as biological nitrification inhibition (BNI). Here, we attempt to characterize BNI in sorghum (Sorghum bicolor). In solution(More)
Nitrification, a key process in the global nitrogen cycle that generates nitrate through microbial activity, may enhance losses of fertilizer nitrogen by leaching and denitrification. Certain plants can suppress soil-nitrification by releasing inhibitors from roots, a phenomenon termed biological nitrification inhibition (BNI). Here, we report the discovery(More)
The release of chemical compounds from plant roots that suppress soil nitrification is termed biological nitrification inhibition (BNI). Determining the environmental factors that control the synthesis and release of BNI-compounds from Brachiaria humidicola (Rendle) Schweick, a tropical pasture grass that thrives on acid soils, is the focus of this(More)
Nitrification inhibitory activity was found in root tissue extracts of Brachiaria humidicola, a tropical pasture grass. Two active inhibitory compounds were isolated by activity-guided fractionation, using recombinant Nitrosomonas europaea containing luxAB genes derived from the bioluminescent marine gram-negative bacterium Vibrio harveyi. The compounds(More)
Nitrification by soil nitrifiers may result in substantial losses of applied nitrogen through NO3 − leaching and N2O emission. The biological inhibition of nitrification by crop plants or pasture species is not well known. This study was conducted to evaluate the ability of three pasture species, Brachiaria humidicola, B. decumbens and Melinis minutiflora(More)
BACKGROUND Agriculture is the single largest geo-engineering initiative that humans have initiated on planet Earth, largely through the introduction of unprecedented amounts of reactive nitrogen (N) into ecosystems. A major portion of this reactive N applied as fertilizer leaks into the environment in massive amounts, with cascading negative effects on(More)
The ability to suppress soil nitrification through the release of nitrification inhibitors from plant roots is termed ‘biological nitrification inhibition’ (BNI). Here, we aimed at the quantification and characterization of the BNI function in sorghum that includes inhibitor production, their chemical identity, functionality and factors regulating their(More)