International round‐robin study on the Ames fluctuation test

Abstract

An international round-robin study on the Ames fluctuation test [ISO 11350, 2012], a microplate version of the classic plate-incorporation method for the detection of mutagenicity in water, wastewater and chemicals was performed by 18 laboratories from seven countries. Such a round-robin study is a precondition for both the finalization of the ISO standardization process and a possible regulatory implementation in water legislation. The laboratories tested four water samples (spiked/nonspiked) and two chemical mixtures with and without supplementation of a S9-mix. Validity criteria (acceptable spontaneous and positive control-induced mutation counts) were fulfilled by 92-100%, depending on the test conditions. A two-step method for statistical evaluation of the test results is proposed and assessed in terms of specificity and sensitivity. The data were first subjected to powerful analysis of variance (ANOVA) after an arcsine-square-root transformation to detect significant differences between the test samples and the negative control (NC). A threshold (TH) value based on a pooled NC was then calculated to exclude false positive test results. Statistically, positive effects observed by the William's test were considered negative, if the mean of all replicates of a sample did not exceed the calculated TH. By making use of this approach, the overall test sensitivity was 100%, and the test specificity ranged from 80 to 100%.

Combined anaerobic–ozonation process for treatment of textile wastewater: Removal of acute toxicity and mutagenicity

“…This strain was chosen because it lacks O6-methylguanine DNA methyltransferases and is thus highly sensitive to mutagenic alkylating agents and nitrosamines that may be formed during ozonation of wastewater [22,29]. The Ames fluctuation test was performed according to the procedure described in Reifferscheid et al [30]. The strain was inoculated in 10 ml growth medium in presence of 10 g/l kanamycin and 25 g/l chloramphenicol and incubated at 37 • C, 150 rpm for 10 h. A 24 wells micro plate was filled with 3 replicates of water samples, negative (demineralized water) and positive control (0.2% propylene oxide).…”

Assessing the Mutagenic Potential of Surface Sediments from Beijing Guanting Reservoir toSalmonella typhimurium

“…However, the organic extract substrate was very complicated and might contain other mutagens, such as nitro aromatics or aromatic amines. These contaminants may exist at a very low concentration yet still be able to cause mutagenicity effects (Reifferscheid et al, 2012;Gallampois et al, 2013). Therefore, further chemical measures should be required to identify such compounds in sediment samples.…”

The ecotoxic potential of a new zero-valent iron nanomaterial, designed for the elimination of halogenated pollutants, and its effect on reductive dechlorinating microbial communities

“…For measurement of the mutagenic potential, a modification of the standard Ames assay was conducted according to ISO guideline 11350 (ISO, 2012), Reifferscheid et al (2012) and Heger et al (2012). Mutagenicity was investigated using the Salmonella typhimurium strains TA98 and TA100 with the Ames fluctuation test (with and without the metabolic activation S9 mix).…”