[Effect of the pretreatment with organic acid buffer solutions on the recovery of Legionella species from environmental water samples].
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).
Kasuga
Osamu
O
Tanabe R&D Service Co., Ltd.
Takagi
Kimiko
K
Misawa
Hitoshi
H
Onozawa
Masato
M
Chiba
Eiji
E
Tani
Kato
K
Ikedo
Masanari
M
D000143:Acids; D001419:Bacteria / Q000187:drug effects*; D002021:Buffers; D002951:Citrates / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007875:Legionella / Q000302:isolation & purification*; D014871:Water Microbiology
D000143:Acids; D002021:Buffers; D002951:Citrates