Effect of water treatment with low-temperature and low-pressure glow plasma of low frequency on the growth of selected microorganisms

Tap water treated in air with low-temperature and low-pressure glow plasma of low frequency was tested for its either stimulation or inhibition of the growth of the selected microorganisms commonly colonizing human organism. The growth of chosen microorganisms was monitored by estimation of optical density of their colonies. The fairly linear growth against time of all microorganisms under study accelerated after 12 h from the beginning of the experiment. Colonies of E. coli and S. cerevisiae breed in the plasma treated water had an approximately 20% stimulation of the growth which was observed between 12 and 24 h. Neither stimulation nor inhibition of the growth could be noted for colonies of Aspergillus niger, Candida albicans, Yarrowia lipolytica, and Enterococcus faecalis, in whole period of observation. The plasma-treated water had no effect upon the growth of Mycobacteria. Independently of the water tested, M. tuberculosis started proliferating on the 14th day of the experiment, M. intercellulare and M. kansai after 9 days, and the growth of M. fortuitos could be observed after 3 days.