Abstract
A pure culture of Microcystis aeruginosa (NIES-98) was exposed to low-pressure (LP) or medium-pressure (MP) UV lamps and subsequently incubated under white light fluorescent lamps allowing both photoreactivation and photosynthesis. During incubation, profiles of the number of existing cells and UV-induced DNA damage were determined for each sample.
The growth of Microcystis aeruginosa was inhibited by the exposure to LPUV or MPUV. Only a minor difference was observed between LPUV and MPUV both in the cell number and the DNA damage.
UV-induced DNA damage just after UV irradiation was almost the same regardless of the UV fluence or the UV lamp. Meanwhile, the UV-induced DNA damage was repaired during 1day incubation after UV exposure, and the number of DNA damage appeared somehow proportional to the UV fluence after 1day incubation.
A comparison between the cell number and the number of DNA damage implied that the UV-induced DNA damage mainly contributed to the cell number reduction of Microcystis aeruginosa.