Kasuga Osamu, Takagi Kimiko, Misawa Hitoshi, Onozawa Masato, Chiba Eiji, Tani Kato, Ikedo Masanari
Tanabe R&D Service Co., Ltd.
Kansenshogaku Zasshi. 2002 Dec;76(12):1010-5. doi: 10.11150/kansenshogakuzasshi1970.76.1010.
Anti-microbial effect of the pretreatment with various organic acid buffer solutions against co-existing microorganisms which were isolated from cooling-tower water samples along with Legionella spp. was examined. Among several buffer solutions, a 0.1 M potassium citrate-citric acid buffer solution (hereafter, citrate buffer solution, pH 2.2) hardly affected the recovery of Legionella spp., but effectively inhibited the growth of co-existing microorganisms. To evaluate the buffer action of these buffer solutions, pHs of 9 cooling-tower water samples were evaluated after addition of an equal volume of each buffer solution. When a citrate buffer solution. pH 2.2 was combined to a 200-fold concentrated solution of each cooling-tower water sample, the pH of the combined solution became 2.5 to 2.7 and maintained a stably low pH value than that (pH 3.0 to 7.4) obtained after mixture of a 0.2 M HCl-KCl buffer solution (hereafter, HCl buffer solution, pH 2.2), suggesting strong buffer action of the citrate buffer solution, pH 2.2 in the combined solutions. Furthermore, when cooling-tower water samples were pretreated with a citrate buffer solution, pH 2.2, the recovery of Legionella spp. was successful in 7 out of 9 cooling-tower water samples, suggesting 3 times higher recovery rate than that obtained by addition of a HCl buffer solution, pH 2.2 (3 out of 9 cooling-tower water samples).
研究了用各种有机酸缓冲溶液预处理对与嗜肺军团菌一起从冷却塔水样中分离出的共存微生物的抗菌效果。在几种缓冲溶液中，0.1M柠檬酸-柠檬酸钾缓冲溶液（以下简称柠檬酸盐缓冲溶液，pH 2.2）几乎不影响嗜肺军团菌的回收率，但能有效抑制共存微生物的生长。为了评估这些缓冲溶液的缓冲作用，在加入等体积的每种缓冲溶液后，对9个冷却塔水样的pH值进行了评估。当将pH 2.2的柠檬酸盐缓冲溶液与每个冷却塔水样的200倍浓缩溶液混合时，混合溶液的pH值变为2.5至2.7，并保持比加入0.2M HCl-KCl缓冲溶液（以下简称HCl缓冲溶液，pH 2.2）后得到的pH值（pH 3.0至7.4）稳定更低，这表明pH 2.2的柠檬酸盐缓冲溶液在混合溶液中具有很强的缓冲作用。此外，当用pH 2.2的柠檬酸盐缓冲溶液对冷却塔水样进行预处理时，9个冷却塔水样中有7个成功回收了嗜肺军团菌，回收率比加入pH 2.2的HCl缓冲溶液（9个冷却塔水样中有3个）高出3倍。
