Anti-Bacterial Phenomena

Photocatalyst generates Hydroxyl-Radical excited by the UV light energy; this Hydroxyl Radical can oxidize the cell membrane to pierce holes; With the Osmotic pressure difference, cell lipid percolate through out the hole, which is the life end of an individual cell. Also through piercing hole Hydroxyl Radical penetrate into the cell, and then destruct DNA spiral portion not to generate the secondary generation of the individual bacteria; which eliminates total growth of the population.

ABWith simply UV light sterilize Bacteria, however, Bacteria can survive and be reactivated with irradiated by the visible lights. Photocatalyst reaction can be complementally for UV sterilization.

To confirm the Photocatalyst Anti-bacterial property; the data shown is to experiment the anti-bacterial effect of the Photocatalyst coated Stainless steel plate under the fluorescent light of the regular room use.


In accordance with the Experimental procedure “Test for antimicrobial activity of film contact and shield the Light method: Shield condition”, dripping Microbes dissolved solution (Escherichia coli NBRC-3972) with Neutrient Broth 1/500  onto the specimen surface, and then attach the film kept with 20-25 degC temperature irradiated by the fluorescent light. By measuring the number of the live microbes in the microbe solution on the specimen, Anti-bacterial property is measured.


As shown below, the number of the bacteria Escherichia coli was count as 3.0×105, at the starting. on the Photocatalyst coated Stainless steel plate; and it is measured as less than 10, after 24hours irradiation by a fluorescent light.

Bacteria tested

Measurement Method


Bacterial Counts

at one specimen





No light

Ambient 8 hrs





With Light

Ambient 8 hrs





From the result appeared above, Photocatalyst coating is indicated holding strong Anti-bacterial property. This property is useful toward the food processing, factories especially treating process under high humidity as a countermeasure to Bacteria or Molds growth on the facility walls.

On site experiment

AB ceiling

The photos shown above, indicate the real site application evidence.

The ceiling of the Milk factory which produces Yogurt was coated with Photocatalyst.

The photo was taken at 6 months spending after Photocatalyst coating was made.

The result is obvious, with Photocatalyst no molds to be appeared with the fluorescent light exposure, while the molds returned on the non-coated ceiling surface after 3 months period.


Bookmark this on Google Bookmarks
Share on Facebook
Share on LinkedIn