.... 1s Eff]cacy experiments using glutarrddehyde against cysts of field isolates were also performed by Professor Berk as described Those results are reported in Table 3. RESULTS E~cacy vs. Tetrahymena The etlcacy of several commonly used water treatment biocides against a pure strain of Tetrahymerra...

... to isothiazolones. Cysts were tested separately. The minimum lethal concentration (MLC) for trophozoites was between 31-62 ppm of the biocide product, which is slightly less than the MLC for an amoebae species from the United States; and cyst forms were twofold more resistant than those of the U.S. species...