Browsing by Author "Ghalamboran, M. R."

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    Symbiotic nitrogen fixation enhancement due to magnetite nanoparticles
    (Cranfield University, 2011-01) Ghalamboran, M. R.; Ramsden, J. J.
    Population pressure on food production motivates the search for new ways to increase the productivity of arable land, especially land rendered marginal by salinity or aridity. The global thesis motivating this work is that nanotechnology can benefit agriculture. My specific thesis is that that part of nanotechnology concerned with nanoparticle production can benefit soybean yield. I have focused on symbiotic nitrogen fixation, and systematically investigated the effects thereon of magnetite nanoparticles introduced into the rhizosphere.My main finding is that the presence of these nanoparticles increases nodulation -- both the number of nodules and the size of individual nodules. Since the experiments were carried out on plants provided with minimal nutrients, there was no corresponding increase in vegetative growth. Some evidence was obtained for the nanoparticles enhancing the "molecular dialogue" between soybean root and the Bradyrhizobia that become incorporated in the nodules. A secondary finding is that the nanoparticles enhance the growth rate of Bradyrhizobia in culture, which is advantageous for the preparation of inocula. Furthermore, coating soybean seeds with nanoparticles and Bradyrhizobia prior to planting enhances survival of the bacteria, and therefore increases the efficiency of subsequent nodulation.
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    Viability of Bradyrhizobium japanicum on soybean seeds enhanced by magnetite nanoparticles during desiccation
    (2010-03-31T00:00:00Z) Ghalamboran, M. R.; Ramsden, Jeremy J.
    The aim of this study was to investigate whether magnetite nanoparticles affect the viability of Bradyrhizobium japanicum cells residing on the surface of soybean seeds during desiccation. Different concentrations of nanoparticles suspended in liquid medium, mixed with and adhering to Bradyrhizobium japanicum, were investigated at two temperatures, using both soybean seeds and glass beads as surrogates. Statistical design was a complete randomized block (CRB) in a factorial 6×2×2×6 experimental arrangement with four replications. The most important variable was the viability of Bradyrhizobium on the surface of the seeds. The nanoparticles increased Bradyrhizobium viability and inoculated seeds stored at low temperature had greater viability when nanoparticles had been added. At the optimum nanoparticle concentration, 50% bacterium viability on the seeds was retained after 5 days at 4ºC. Possible explanations for the observed effects are prop