A joint research group between Nagoya University and Meijo University has developed a method for producing water without using pesticides by irradiating oxygen radicals (oxygen atoms with unpaired electrons resulting from the dissociation of shared electron pairs in oxygen molecules) generated in low-temperature plasma. We have developed a technology to sterilize cultivation solutions.
Hydroponic farming overcomes the risks of climate change by feeding the roots with a nutrient-containing solution, enabling sustainable food production with high productivity and efficient use of land and water resources. It is attracting attention as a production system. However, it is necessary to use pesticides in the solution to prevent disease and spoilage, and disposal of the solution is also an issue.
This research group has been the first in the world to realize a sterilization technology that uses low-temperature plasma generated from electrical energy without using disinfectants. This time, we have further developed this technology and developed a new cultivation solution sanitation control technology by irradiating oxygen radicals generated by low-temperature plasma.
It is said that the growth of E. coli can be suppressed by irradiating a cultivation solution containing the amino acid tryptophan as a nutrient with oxygen radicals. At this time, within E. coli cells, changes were observed in metabolites derived from the glycolytic system and tricarboxylic acid cycle, which are essential for survival, as well as a marked inactivation of the GAPDH enzyme, one of the glycolytic enzymes. It was found that E. coli was killed due to metabolic abnormalities.
The research group believes that sterilization is achieved by irradiating tryptophan with oxygen radicals, and the generated tryptophan radicals induce enzyme inactivation and metabolic abnormalities within E. coli.
Furthermore, it is said that tryptophan radicals then pass through formylkynurelin (FKYN) and lead to the production of kynurelin (KYN), and since these FKYN and KYN have no bactericidal effect, it is assumed that the bactericidal effect only occurs during oxygen radical irradiation. work.
This technology can achieve a sterilizing effect simply by turning the atmosphere into low-temperature plasma using electrical energy, so it is expected to contribute to the reduction of chemical pesticides, the elimination of fossil fuels, and the reduction of greenhouse gases. In addition, since the solution can be sterilized on the spot during the cultivation period, it has the potential to significantly reduce the amount of waste solution, and is expected to be put to practical use as a fundamental technology for sustainable crop production.
Paper information:【Environmental Technology & Innovation】Oxygen radical irradiation transforms an organic fertilizer-tryptophan into an environment and human-friendly bactericide
