Grazing characteristics of musty-odor-compound-producing Phormidium tenue by a microflagellate, Monas guttula

The grazing characteristics of musty odorous 2-methylisoborneol-(MIB)-producing Phormidium tenue by a microflagellate, Monas guttula, were studied in a batch culture experiment. M. guttula, which was isolated from the biological treatment facility of water supply treatment processes, could effectively graze the viable cells of P. tenue with 98% removal ratio within 24 h at an initial concentration of 3.4 x 10⁶ filaments ml^-1. The maximum specific growth rate of 3.8 day^-1 and the saturation coefficient of 0.5 mg liter^-1 of P. tenue concentration as a substrate were obtained. M. guttula was found to be the main contributor of MIB degradation. Removal ratio of MIB with the initial concentration of 120 μg liter^-1 by M. guttula was 42% at 48 h of cultivation, but bacteria without M. guttula could not degrade MIB.