Evaluation of some halogen biocides using a microbial biofilm system

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• 作者：Mariko Tachikawa ; Masakatsu Tezuka ; Masahiro Morita ; Katsuhisa Isogai and Shoji Okada
• 关键词：Biofilms ; Disinfection efficacy ; Halogen biocides ; HOCL ; Chloramines ; Bromamines ; Bromochloramine ; Biofilm images by CLSM
• 刊名：Water Research
• 出版年：2005
• 出版时间：2005
• 年：2005
• 卷：39
• 期：17
• 页码：4126-4132
• 全文大小：869 K

文摘

A simple method for the formation of microbial biofilms of three species, Pseudomonas fluorescens, Pseudomonas aeruginosa, and Klebsiella pneumoniae, on a small glass slide was established, and its suitability for evaluation of disinfectant efficacy was examined. The biofilms formed were observed in situ by confocal laser scanning microscopy (CLSM). Using the biofilms established, biocidal efficacy of several halogen biocides, such as hypochlorite (HOCl), bromochlorodimethylhydantoin (Br, Cl-DMH), ammonia monochloramine (NH₂Cl), a stabilized hypobromite biocide named STABREX^®, and a mixed solution of NH₄Br and HOCl, was evaluated. The formation of NHBrCl in the mixed solution was indicated by UV spectra analysis. Biofilm cells were more resistant to these biocides than planktonic cells and the extent of resistance varied with the biocide tested. Among the biocides tested, the biocidal potency of HOCl was the most susceptible to the change brought about by biofilm formation. By CLSM observation, differences in biofilm conformation were revealed between the microbial species. The efficacy of the biocide tested varied with the structure of biofilms formed. The assay method developed in the present study would be useful for further investigation on biofilm disinfection.