Abstract
The water extract of igusa (Juncus effusus var. decipiens) had a wide range of antibacterial activities against Bacillus subtilis, Salmonella typhimurium, Escherichia coli, Legionella pneumophila, and resident skin bacteria. Among these, the effect against L. pneumophila and E. coli is expected to be useful for microbial controlling in bathrooms, especially in recirculating bathtubs. The inside of igusa has a porous structure with well-developed spongy tissue made up of stellate cells, which gives it a high ability to adsorb odorous components, formaldehyde, nitrogen dioxide. Since igusa has antibacterial properties against microorganisms that cause bad odors, it is suggested that a tatami is also useful in preventing household odors and indoor pollutants caused by microorganisms. Regarding fungi, it had an antifungal effect against trichophyton fungus but was ineffective against Aspergillus and Rhizopus spp. Since almost no mold was detected on the tatami before delivery, it was suggested that the mold that tends to grow on unused tatami does not originate from the tatami, but rather grows due to mold spores that fall from the air in the indoor environment. The aroma components of igusa did not show any antibacterial effect against E. coli, suggesting that the antibacterial effect of igusa may be mainly due to water-soluble components.
