研究開始時の研究の概要 |
To check the iron acquisition and export, PG will be tested for the release of iron during its EET by ferrozine assay, differential pulse voltammogram (DPV) analysis and spectroscopic iron assays, i.e., export if (Fe2+) via an unknown iron exporter.
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研究実績の概要 |
Porphyromonas gingivalis (PG) is a typical member of the dental plaque biofilm found on the tooth surface. PG is a keystone pathogen associated with chronic oral diseases and systemic inflammatory disorders such as cardiovascular, arthritic, and neurodegenerative diseases. This research aims to identify the critical mechanisms of EET coupled iron export in PG leading to inflammation and corrosion. PG can take up soluble Fe2+ and store it in oxidized Fe3+ form intracellularly to utilize in times of iron limitation. However, whilst essential to avoid toxicity due to excess iron, PG iron homeostasis and the export mechanism is not well understood. This study investigated and compared the extracellular elecctron transport (EET) capabilities of PG using various amino substrates. With a coulombic efficiency (CE) of 2.8%, P. gingivalis considerably increased current with histidine metabolism compared to other substrates, which is around 1000 times higher than the CE that P. gingivalis was previously reported to have for glucose oxidation (0.003%). During this research, important identification of Iron reduction by P. gingivalis was tested and identified the same, indicating the possible mechanism of EET coupled with Iron reduction by P. gingivalis. And iron has showed the impact on the growth of pathogen reflected in the electron transfer capability as well. Our findings demonstrate that amino acids, particularly histidine, which has an eight times greater current production rate than glucose, can serve as carbon sources for the asaccharolytic pathogen P. gingivalis.
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