降水中の微生物粒子の存在量  [in Japanese] Abundance of biological micro-particles in rain water  [in Japanese]

The study of biological micro-particles in rain water have hardly ever published because sampling, storage and measurement are difficult tasks to perform without contamination. This study carefully carried out laboratory experiments and field works at three sites (Shizuoka University, Mt. Fuji and Mt. Norikura). Biological particles in rain water were found to be bacteria and other organisms or organic debris such as spore, pollen and leaf debris. The purpose of this study is to measure the number of bacteria exactly. In order to perform this purpose, more examination of sampling, storage samples and measurement without contamination is required. An alternative approach is to stain the bacteria with DAPI and enumerate them by epifluorescence microscope. As a result of laboratory experiments, the blank of sampling and measurement was about 7.4 x 10^3 cell/ml. And then, the concentrations of atmospheric samples at three sites were 2.0 X 10^4 to 4.8 x 10^4 cell/ml in rain water. Therefore, 13 to 27 % of the total concentration in rain water as a background value was comprised, which comes mainly from Milli-Q water. And then, according to laboratory experiments, the error of counting bacterias was ±1,000 for 18,000 (±6%). It was confirmed on the measurement for bacteria in rain water.

The study of biological micro-particles in rain water have hardly ever published because sampling, storage and measurement are difficult tasks to perform without contamination. This study carefully carried out laboratory experiments and field works at three sites (Shizuoka University, Mt. Fuji and Mt. Norikura). Biological particles in rain water were found to be bacteria and other organisms or organic debris such as spore, pollen and leaf debris. The purpose of this study is to measure the number of bacteria exactly. In order to perform this purpose, more examination of sampling, storage samples and measurement without contamination is required. An alternative approach is to stain the bacteria with DAPI and enumerate them by epifluorescence microscope. As a result of laboratory experiments, the blank of sampling and measurement was about 7.4 x 10^3 cell/ml. And then, the concentrations of atmospheric samples at three sites were 2.0 X 10^4 to 4.8 x 10^4 cell/ml in rain water. Therefore, 13 to 27 % of the total concentration in rain water as a background value was comprised, which comes mainly from Milli-Q water. And then, according to laboratory experiments, the error of counting bacterias was ±1,000 for 18,000 (±6%). It was confirmed on the measurement for bacteria in rain water.