In the context of the global nitrogen cycle, the importance of inorganic nitrate for the nutrition and growth of marine and freshwater autotrophic phytoplankton has long been recognized. In contrast, the utilization of nitrate by heterotrophic bacteria has historically received less attention because the primary role of these organisms has classically been considered to be the decomposition and...

denitrification is a reduction of nitrate by heterotrophic and autotrophic bacteria that may ultimately produce molecular nitrogen (n2) through a series of intermediate nitrogen compounds.vermiculite is a hydrous phyllosilicate mineral (mg, fe+2,fe+3)3[(al,si)4o10](oh)2·4h2o with several layers for bacterial immobilization. the goal of this study was removal of nitrate from water with vermiculi...

The effect of nitrate on symbiotic nitrogen fixation by root nodules of cowpea (Vigna unguiculata L., Walp., cv. California Blackeye) and lupine (Lupinus augustifolius L., cv. Frost) plants inoculated with nitrate reductase-expressing and nitrate reductase-nonexpressing Rhizobium strains were examined. Nitrate reductase of Rhizobium bacteroids in the nodules of cowpea and lupine reduced nitrate...

Understanding how plants sense and respond to changes in nitrogen availability is the first step toward developing strategies for biotechnological applications, such as improvement of nitrogen use efficiency. However, components involved in nitrogen signaling pathways remain poorly characterized. Calcium is a second messenger in signal transduction pathways in plants, and it has been indirectly...

the stoichiometric parameter namely “yield coefficient” associated with growth of certain organism can be determined by direct measurement and/or calculated indirectly. the focus of this paper was on the anoxic yield of heterotrophic organisms using ethanol as an external carbon source during the denitrification process. in the literature, it was observed that yield coefficients can vary for th...

RATIONALE Because of the threat of bombings using improvised explosives containing ammonium nitrate (AN), law enforcement and intelligence communities have been interested in stable isotope techniques for tracking and discriminating AN sources. Separate analysis of the AN component ions ammonium and nitrate would add discriminatory power to these techniques. METHODS Ammonium ions in dissolved...

The taxis response of Rhodobacter sphaeroides 2.4.1 and 2.4.3, Rhodopseudomonas palustris, and Agrobacterium tumefaciens to nitrate and nitrite was evaluated by observing the macroscopic behavior of cells suspended in soft agar and incubated under various conditions. R. sphaeroides 2.4.3, which is capable of both nitrate and nitrite reduction, showed a taxis response to both nitrate and nitrite...

production of onion all thruough the year particularly in semi tropical regions has been considered as an alternative to fulfil the local markets needs. in order to determine the best amount and method of urea fertilizer application so that to have higher yeild and lower amount of nitrate content the effects of seven levels of urea fertilizer including 0, 90, 180, 270, 360, 450 and 540 kg of ni...

Nitrogen assimilation plays a vital role in plant metabolism. Assimilation of nitrate, the primary source of nitrogen in soil, is linked to the generation of the redox signal nitric oxide (NO). An important mechanism by which NO regulates plant development and stress responses is through S-nitrosylation, that is, covalent attachment of NO to cysteine residues to form S-nitrosothiols (SNO). Desp...