In this study, to improve the accuracy and precision of microbiological testing of waters from the source and purification processes, we newly developed a method in which sample water is filtered through a polycarbonate filter and then microorganisms are detached and collected using a vortex mixer. The strength and time of vortex mixing were optimized using a total of 6 strains of Dolichospermum crissum, Microcystis aeruginosa, Oscillatoria tenuis, Pseudanabaena limnetica, Ankistrodesmus falcatus, and Closterium aciculare inoculated into source water amples. The developed method was validated by the eight institutions to which the authors belong and it was demonstrated that its recovery rate was generally higher than that of a conventional pipetting method. Furthermore, the developed method was also effective in recovering Cyclotella sp. from purified water samples.

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[in Japanese]

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