Abstract 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT)/2-methyl-4-methyl-isothiazolin-3-one (MIT) biocides or preservation agents are chemically stabilized with MgCl2, Mg(NO3)2 or CuSO4. The role of these stabilization agents in cell inactivation was investigated with Pseudomonas aeruginosa MDC isolated from a water-based paint tank biofilm. 10 ppm/active ingredient (ai) of CMIT/MIT commercial formulation or CuSO4 alone did not lead to elimination of viable cell counts. Inactivation times of 3.5h (CuSO4) or 24h (CMIT/MIT) with 100 ppm/ai biocides were further reduced to 2h (CuSO4) and 6h (CMIT/MIT), respectively, when the dose was increased to 1000 ppm/ai, with no synergism observed between these two biocides. Copper from cells exposed to high doses was remobilized back into the solution in quantities sufficient to become biocidal to fresh cells whilst EDTA added prior to copper prevented cell inactivation. Mg(NO3)2 was not biocidal. Cell death defined as the inability to recover biocide-treated cells after 120h incubation in the medium used for growth required minimum contact times of 2.5h (1000 ppm/ai) or 3h (100 ppm/ai) with copper sulfate and 24h with 100 ppm/ai or 1000 ppm/ai CMIT/MIT. Pseudomonas aeruginosa MDC were not lysed after exposure to either copper or CMIT/MIT but only copper made the membrane permeable to propidium iodide. Both copper and CMIT/MIT inhibited the activity of the electron transport chain and reduced INT activity in Pseudomonas aeruginosa MDC to residual levels. The latter effect was also observed with Mg(NO3)2. Preventing microbial growth in products protected by CMIT/MIT requires maintenance of effective biocide doses over the entire shelf life.

中文翻译：

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异噻唑啉酮和杀菌剂稳定剂灭活铜绿假单胞菌 MDC

摘要 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT)/2-methyl-4-methyl-isothiazolin-3-one (MIT) 杀菌剂或防腐剂用 MgCl2、Mg(NO3) 进行化学稳定2 或 CuSO4。这些稳定剂在细胞灭活中的作用通过从水性涂料罐生物膜中分离的铜绿假单胞菌 MDC 进行了研究。10 ppm/活性成分 (ai) 的 CMIT/MIT 商业制剂或单独的 CuSO4 不会导致活细胞计数的消除。当剂量增加到 1000 ppm/ai 时，3.5 小时 (CuSO4) 或 24 小时 (CMIT/MIT) 与 100 ppm/ai 杀生物剂的灭活时间分别进一步减少到 2 小时 (CuSO4) 和 6 小时 (CMIT/MIT)，在这两种杀生物剂之间没有观察到协同作用。来自暴露于高剂量的细胞的铜以足以对新鲜细胞成为杀生物剂的量重新迁移回溶液中，而在铜之前添加的 EDTA 可防止细胞失活。Mg(NO3)2 不是生物杀灭剂。细胞死亡定义为在用于生长的培养基中孵育 120 小时后无法恢复经杀生物剂处理的细胞，所需的最短接触时间为 2.5 小时（1000 ppm/ai）或 3 小时（100 ppm/ai）与硫酸铜和 24 小时与 100 ppm /ai 或 1000 ppm/ai CMIT/MIT。铜绿假单胞菌 MDC 在暴露于铜或 CMIT/MIT 后均未裂解，但只有铜使膜可渗透碘化丙啶。铜和 CMIT/MIT 都抑制了电子传递链的活性，并将铜绿假单胞菌 MDC 中的 INT 活性降低到残留水平。使用 Mg(NO3)2 也观察到后一种效果。