Organic fertilizers are useful in hydroponic agriculture to bring about a sustainable society with minimal pollution. Irradiation of L-tryptophan (L-Trp) solutions with electrically neutral atomic oxygen produces immediate bactericidal activity. After oxygen radical irradiation of an L-Trp-containing Escherichia coli suspension at pH 6.3 for 5 min, a colony-forming unit assay showed a 6-log reduction in the number of surviving E. coli. Kynurenine and N’-formylkynurenine were identified as irradiation products in the solution using liquid chromatography–mass spectroscopy and nuclear magnetic resonance spectroscopy. Tryptophan radicals (Trp•) are precursors of kynurenine and N’-formylkynurenine and are detected using spin-trap electron spin resonance. The bactericidal effect is mediated by central carbon metabolism via enzyme deactivation in E. coli. Enzymatic deactivation via the oxygen radical irradiation of a solution containing the amino acid L-Trp eventually resulted in bacterial death.
CITATION STYLE
Iwata, N., Ishikawa, K., Nishikawa, Y., Kato, H., Shimizu, M., Kato, M., … Hori, M. (2024). Oxygen radical irradiation transforms an organic fertilizer L-tryptophan into an environment and human-friendly bactericide. Environmental Technology and Innovation, 33. https://doi.org/10.1016/j.eti.2023.103496
Mendeley helps you to discover research relevant for your work.