The 12th European Nitrogen Fixation Conference took place in Budapest
Fixed nitrogen is probably the main plant nutrient that limits agricultural production worldwide. For most developed countries this limitation can be alleviated by the use of nitrogenous fertilizers. The increased cost of fertilizer nitrogen, concern about nitrates in water supplies, and the limited availability of fertilizer in developing countries are major factors influencing a desire to obtain more fixation by biological means.
The conference took place between the 25th and 28th of August.
The significance of nitrogen fixation on earth
It is likely that nearly all plant species benefit from nitrogen fixation by bacteria associated with their roots. How much they benefit appears to be related directly to the degree of complexity of the interaction between the plant and nitrogen‐fixing bacteria. For example, some leguminous plants, which have root nodules containing rhizobia, can fix more than 100 kg N per hectare per annum, whereas some grasses which have nitrogen‐fixing bacteria associated with their roots may only support fixation of 10 kg N per hectare per annum or less.
The main goals of nitrogen fixation research
Several important objectives have been proposed by the research workers on the need to increase the contribution from the biological nitrogen fixation to N inputs in agricultural systems. These objectives include the need for maximization of the N-fixing potential of the present agricultural systems, the introduction and expansion of the capacity to fix N to new farming system. The precise quantities of nitrogen supplied to the biosphere by all the various processes is not accurately known, but it is generally agreed that the biological fixation of nitrogen gas is of major importance accounting for some hundred million tons of nitrogen fixed per year. The major agronomic benefits from symbiotic biological N-fixation are the direct input of atmospheric nitrogen to the agricultural system and the control of crop diseases as a consequence of involving legumes in crop rotations. "The environmental benefits from using biological N-fixation are seen to be associated with the replacement of chemical based technologies with a biological system. These possible advantages include the decreased inputs of fertilizer N resulting in decreased levels of ground water pollution by nitrates and reduced outputs of greenhouse gas production because the process of fixing nitrogen biologically does not depend on fossil fuel.
The major amount of fixed N is contributed by legume symbioses and thus providing significant amounts of fixed N to agricultural systems. Nitrogen fixing legumes are significant components of many agricultural systems.
Opening CeremonyJens Stougaard - Chair of the European Advisory Board of ENFC
Ádám Török - Secretary General of the Hungarian Academy of Sciences
Éva Kondorosi – Chair of the Local Organizing Committee source: enfc2016.hu/Tamás Thaler
Investigating biological nitrogen fixation at the Biological Research Center of the Hungarian Academy of Sciences, Szeged
The Biological Research Centre established by the Hungarian Academy of Sciences has carryed out fundamental research concerning the nitrogen fixation in nature since the early seventies of the last century.
In the Institute of Biochemistry the model system is the Sinorhizobium – Medicago symbiosis resulting in the formation of root nodules where bacteria inside the plant cells are irreversibly converted to non-cultivable large polyploid nitrogen fixing bacteroids. The symbiosis is of mutual benefit. The bacteria by reducing the atmospheric nitrogen to ammonia satisfy the nitrogen need of the host plant, while the plant provides carbon sources and energy for the bacteria.
The differentiation of bacteroids is under host control and mediated by at least 600 symbiotic peptides.
The researchers intend to characterize the activities and modes of action of symbiotic plant peptides and identify master regulators involved in the differentiation of nitrogen fixing bacteria. Since the nodule is a remarkable source of novel bioactive peptides they test the peptide activities also beyond symbiosis in vitro in other microbes and organisms for potential biotech applications.
Please click here to see the The 12th European Nitrogen Fixation Conference website.