Abstract
We attempted to clarify in detail the conditions of disinfection using electrolyzed strongly acidic water (ESW) against Mycobacteria, and the recovery of the disinfection potential of inactivated ESW by re-electrolysis. We mixed ESW containing 10, 20, and 30 ppm free chlorine with M. bovis cells (105–108 CFU/mL) for 0–7 min. The disinfection potential of ESW positively correlated with free chlorine concentration, and negatively correlated with the initial density of bacterial cells. To clarify the recovery of the disinfection potential of inactivated ESW by re-electrolysis, we mixed ESW containing 10 ppm free chlorine with M. bovis cells (107 CFU/mL) for 1 min. The number of viable cells decreased to 1/103, but the cells were still detected. After re-electrolysis for 7 min, viable cells were not detected. Moreover, we confirmed by reusing the re-electrolyzed water against M. bovis cells that it regained its disinfection potential. These findings indicate that ESW once inactivated during disinfection can be re-activated by re-electrolysis. In conclusion, we were able to clarify in detail the conditions of ESW against Mycobacteria, and found the recovery of the disinfection potential of inactivated ESW by re-electrolysis.
