A Review of the Microtox® Toxicity Test System for Assessing the Toxicity of Sediments and Soils

Abstract

Use of Microtox for screening sediment or soil samples from contaminated systems either alone or in combination with a battery of other tests is supported by an ever-increasing number of comparative studies demonstrating its utility, sensitivity, rapidity and affordability. Organic solvent extracts and direct solidphase material provide an assessment of the potential toxicity exerted by both dissolved and bound contaminants. In contrast, tests utilizing pore water or elutriates may be limited to assessing the contribution of dissolved contaminants only. Each approach is limited in the scope of its applications. The apparent toxicity of elutriates can be a function of extraction solvent and overall procedure. The apparent toxicity of solid-phase samples is influenced by sample color and composition — more specifically, the ratio of clay to silt. However, in general, the results obtained through in laboratory testing with the Microtox test system are often consistent with the results of both sediment invertebrate in laboratory toxicity tests and macroinvertebrate field surveys. There is also evidence that toxicity assessments obtained with the Microtox test system are related to analytically derived concentrations of certain classes of contaminants.

Evaluation of land farming and chemico-biological stabilization for treatment of heavily contaminated sediments in a tropical environment

“…Furthermore, the stabilization treatment not only reduced the acute toxicity completely but also actually caused stimulation (increased bioluminescence) in the bioassay. This bioassay is a good tool to evaluate general toxicity in the environment and the results are consistent with toxicity to soil and sediment invertebrates (Doherty, 2001).…”

Solid-Phase Contact Assay That Uses alux-MarkedNitrosomonas europaeaReporter Strain To Estimate Toxicity of Bioavailable Linear Alkylbenzene Sulfonate in Soil

“…It has often been stated that only the free (dissolved) pool of an adsorptive pollutant is actually bioavailable and thus able to impose a toxic effect on the soil organisms (8,24). On the other hand, many recent reports have suggested that the adsorbed pollutant pool may also be at least partially available for the microorganisms, both in terms of causing toxic effects (2,3,16,(38)(39)(40) and serving as substrates for biodegradation (26,27). As amended LAS is primarily adsorbed to soil particles in the present soils (I.…”

Assessment of sediment toxicity during anaerobic biodegradation of vegetable oil using Microtox® and Hyalella azteca bioassays

“…The toxicity of the oil-treated-sediments was assessed with two regulatory biotests: the Microtox 1 Solid Phase Test (SPT), which can be used to determine the acute toxicity of sediment, and an amphipod (Hyalella azteca) bioassay, which measures the lethal and sublethal toxicity of sediments. The Microtox 1 test has been used widely over the past two decades for toxicity assessment of soil and sediments (Cook and Wells, 1996;Bombardier and Bermingham, 1999;Doberty, 2001;Lee et al, 2003b), and the Microtox 1 SPT has been used successfully to evaluate the efficacy of oil spill remediation strategies (Lee et al, 1995(Lee et al, , 2003b. Likewise, amphipod survival (e.g., Hyalella azteca, Eohaustorius esturius) has been often used to evaluate sediment toxicity in recent years (Ingersoll et al, , 1996Kemble et al, 1994Kemble et al, , 1998Kemble et al, , 1999Bhattacharyya et al, 2003;Blaise et al, 2004).…”