Abstract
Microcystins (MCs), produced by cyanobacteria, have been one of the main toxic contaminants and threatened quality of drinking water. In this study, an electrolysis cell was introduced to inhibit the cell growth and MCs (MC－RR, MC－YR and MC－LR) production of two Microcystis aeruginosa strains. The changes of cell densities and MCs concentrations (intracellular and extracellular) were examined under different culture condition (electrolysis, aeration and control). The results revealed that the electrolysis cell suppressed cell growth and MCs productions of M. aeruginosa strains without electrolytes. Both cell densities and total MCs concentrations in electrolysis condition decreased from day 2, but those in aeration and control kept increasing. Concentration of extracellular MCs in electrolysis condition was almost equaled to that in aeration and control. On the other hand, intracellular MCs concentration in every cell was lower than these of aeration and control strongly suggested that the MCs production activity of M. aeruginosa was inhibited under the electrolytic condition. The decrease in cell density and MCs production can be attributed to the production of hydroxyl radical by electrolysis cell. These results demonstrate the electrolysis cell treatment is one of the promising method for inhibiting the MCs production and cell growth of cyanobacteria without producing any hazardous toxin.
