Studies on the isolation of a bacteria-free
Microcystis aeruginosa which formed the colonial mucilage were carried out. The first step was consisted of obtaining a unialgal culture of
M. aeruginosa by the capillary-pipette method. In the next step, the unialgal isolate was treated with the UV radiation, various antibiotic additions and capillary-pipette washing methods, respectively. Finally, an axenic clone of
M. aeruginosa which formed a flock was able to be obtained by the capillary-pipette washing method. To clarify the bacteria free the microscopical observation and bacteria growth tests using 6 kinds of bacterial media were carried out. No bacterium was observed in the bacteria free culture of
M. aeruginosa. The axenic
M. aeruginosa was transferred into a new medium periodically for more than a year. The flock forming ability was still present. The UV radiation and antibiotic additions to unialgal
M. aeruginosa diminished the number of associated bacteria significantly. However, a bacteria-free
M. aeruginosa was not obtained by the both methods, for the tolerance levels of
M. aeruginosa and bacteria against UV and antibiotics were similar. The bacteria which attached to
M. aeruginosa belonged mainly to
Flavobacterium spp.
抄録全体を表示