The long-term action of recommended (RC) and near-recommended concentrations of several commercial biocides (Lonzabac 12.100, Genamin CS302D, benzalkonium chloride and 2-phenoxyethanol) on cells of S. cerevisiae wild-type strain DTXII was described using plating tests while short-term effects were determined using the potentiometric fluorescent probe diS-C3(3) that detects both changes in membrane potential and impairment of membrane integrity. A 2-d plating of cells exposed to 0.5xRC of benzalkonium chloride and Genamin CS302D for 15 min showed a complete long-term cell killing, with 2-phenoxyethanol the killing was complete only at 2xRC and Lonzabac caused complete killing at RC but not at 0.5xRC. The diS-C3(3) fluorescence assay performed immediately after a 10-min biocide exposure revealed several concentration-dependent modes of action: Lonzabac at 0.5xRC caused a mere depolarization, higher concentrations causing gradually increasing cell damage; benzalkonium chloride and Genamin CS302D rapidly damaged the membrane of some cells and depolarized the rest whereas 2-phenoxyethanol, which had the lowest effect in the plating test, produced a concentration-dependent fraction of cells with impaired membranes. Cell staining slightly increased during the diS-C3(3) assay; addition of a protonophore showed that part of the remaining undamaged cells retained their membrane potential. Comparison of short-term and long-term data implies that membrane depolarization alone is not sufficient for complete long-term killing of yeast cells under the action of a biocide unless it is accompanied by perceptible impairment of membrane integrity. The results show that the diS-C3(3) fluorescence assay, which reflects the short-term effects of a biocide on cell membranes, can be successfully used to assess the microbicidal efficiency of biocides.

Institute of Physics Charles University 121 16 Prague 2 Czechia

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Microbiol Rev. 1993 Jun;57(2):383-401 PubMed

Folia Microbiol (Praha). 2002;47(2):145-51 PubMed

Redox Rep. 2000;5(5):277-85 PubMed

Folia Microbiol (Praha). 1999;44(3):283-8 PubMed

Mol Microbiol. 1996 Mar;19(6):1159-66 PubMed

Nat Biotechnol. 2004 Jan;22(1):62-9 PubMed

Int J Biochem Cell Biol. 1999 May;31(5):575-84 PubMed

Biochim Biophys Acta. 2001 Mar 9;1511(1):74-9 PubMed

Int J Biochem Cell Biol. 2002 Aug;34(8):931-7 PubMed

Folia Microbiol (Praha). 2003;48(6):754-60 PubMed

Yeast. 1998 Sep 30;14(13):1189-97 PubMed

Biochem Pharmacol. 1960 Oct;5:79-86 PubMed

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