Abstract
The fungicidal activity of acidic electrolyzed water (Aqua oxidizing water, AQ) and nine commercial disinfectants was studied using three methods of contact on two kinds of pathogenic yeast and two kinds of conidia.
In a glass test tube, with a ratio of I to 9 of Fungal suspension 107 cfu/ml water to AQ, the fungi were killed by AQ within one minute, but the same amount of AQ was not effective against fungi suspended in a medium of Sabouraud dextrose broth (SDB). The killing activity of 50 ppm sodium hypochlorite (CL), which included the same amount of chlorine as AQ, was weaker than that of AQ and was also inhibited by SDB. The killing activities of 3% hydrogen peroxide, 500 ppm CL, 1% chloramine T (CT) and 0.5% chlorhexidine gluconate were weaker than that of AQ, but were not inhibited by SDB.
On a stainless steel tray, the fungicidal activity was weaker than the activity observed in the glass tube. After a 30-minute exposure, AQ killed both kinds of yeast completely, but neither type of conidia.
Organic substances influenced the fungicidal activity of AQ. On an agar plate or in the glass tube with proteins, the killing activity of both AQ and 50 ppm CL was inhibired. The influence of CT, a kind of chloric oxidizer, varied according to the pH of the substances.
AQ therefore shows a more potent fungicidal activity than ordinary chloric oxidizers with less chlorine because of its acidity, but is inhibited by organic substances to the same extent as CL which includes the same amount of chlorine. In conclusion, AQ is thus considered to be useful in washing and rinsing the surface of materials for the purpose of sterilization.
