Ammonia is commonly used in commercial crop fertilizers, which in turn can pollute waterways when they run off of fields. New research, however, suggests that engineered bacteria could one day take the place of such fertilizers.
In a study led by Asst. Prof. Florence Mus, scientists at Washington State University genetically engineered new strains of a soil-inhabiting bacteria by the name of Azotobacter vinelandii. While the bacteria was already known to convert ambient nitrogen gas into ammonia, the new strains are able to consistently produce and excrete ammonia at much higher concentrations, regardless of environmental conditions.
In lab tests, when the modified A. vinelandii were added to soil in which rice plants were growing, the plants were observed taking up ammonia produced by the bacteria.
The researchers are now working on developing additional types of A. vinelandii, which produce ammonia at different rates. Specific strains could then be used on specific crop species, based on the plants' ammonia requirements.
In this way, it would be ensured that the plants would use up all the ammonia, so no excess would be left over to run out of the soil and enter nearby waterways. Additionally, farmers wouldn't be paying to use extra fertilizer that wasn't even needed.
"Successful widespread adoption of these biofertilizers for farming would reduce pollution, provide sustainable ways of managing the nitrogen cycle in soil, lower production costs and increase profit margins for farmers and enhance sustainable food production by improving soil fertility," said Mus.
A paper on the study was recently published in the journal Applied and Environmental Microbiology.
