Abstract
In this research, we studied growth characteristics of legionella in water used in circulation system. As a result, we found out that legionella could grow even in purified water with extremely low concentration of organic matters. In further studies with higher concentration of organic matters, growth was remarkable, though utilization of substrate by legionella was low. When water was disinfected by UV irradiation as a measure against legionnaries diseases, we obtained UV dose of 7.2mW ・S/cm^2 to inactivate 99% of legionella.
