Microbial-light · Illuminating black boxes in the nitrogen cycle

Illuminating black boxes in the nitrogen cycle

Currently, climate change predictions describe outcomes of biological ecosystems. However, they avoid noting the changes at the microbial level and their effect on e.g. crop production. Why is it important for society? The predictions of the effects of climate change on crop production concur that they won’t be distributed equally around the world. Most northern countries will see an increase in crop production, however, the rest will suffer from decreases in crop production. A decrease in crop production under an increasing human world population is a recipe for disaster, hence resistance and resilient measures are sought to counteract the impact of climate change. As a consequence, the resistance and resilience of microorganisms involved in the nitrogen cycle affected by physicochemical soil disturbances have to be discovered. The microbial-based function nitrification, which in turn has a direct effect on crop production, need to be part of the current models on climate change. Understanding the resistance and plasticity of soil microbial functions, will enable greater precision in predicting crop production under climate change pressures. Resistant and resilient microbial communities to climate change effects may palliate crop production decrease via the introduction of biofertilizers. Biofertilizers are crop amendments which contain plant growth promoting microorganisms (PGPM). However, these are usually used individually. The use of an individual strain as a biofertilizer increases the chances of its function being less efficient due to the vast completion it faces when inoculated into a natural soil with diverse microbial community. Single PGPMs are studied and used globally as biofertilizers to enhance crop production and increase health by controlling pests, as well as maintaining nutrient cycling. Yet, we believe that the incorporation of these biological units in the fertilizers into complex and diverse soil ecosystems will prevail longer when composed of social multi-species microorganisms. Recently, microbial communities have been observed to function best when the microorganisms have positive or neutral social behaviours. The use of a web based tool called BSocial (http://m4m.ugr.es/BSocial.html), describes the net social behaviour of individual strains, from combinatorial growths of these individuals. Hence, the main objective was to study the impact of disturbances, such as humidity and temperature on soil microorganisms, and observe how their social interactions changed, as well as how the function of nitrification changed before and after the disturbances. Furthermore, enhancement of the BSocial tool would increase further projects using social microorganisms for the creation of multi-species biofertilizers. Physicochemical disturbances affect soil geochemical functions driven by microorganisms, thus further studies should highlight the factors that do not allow for microbial functions to recovery in short time spans in order to predict its effect on crop production. Overall global warming increases stress disturbance frequencies, and these affect soil functions directly, and their macro/microorganisms. Although nitrifying microorganisms are resilient to dry spells, the nitrification process is severely affected with both dry (rel. humidity 5%) and intense temperatures (50°C). However, flooding can also alter the nitrification process in the soil, hence destabilizing the fluctuations of the processes within the nitrogen cycle. Since microbial functions work best with positive or neutral social species, a BSocial R package will be available soon for deciphering social interactions.

Data: CORDIS, © European Union