Toxicological evaluation of feeds with different levels of heavy metals using luminescent microorganisms Photobacterium рhosphoreum
Abstract
Assessment of the toxicity of pollutants is an integral part of the quality and safety control of the animal feed. Today, when determining the toxicity of a particular substance, alternative methods are increasingly being used, which involve using cell cultures, protozoa, and photobacteria in a toxicological experiment. The bioluminescence effect of bacteria makes it possible to use them as a substitute for laboratory animals or as an additional test to determine the effect of toxicants, which significantly reduces the cost of work due to the simplicity and speed of research, high sensitivity, and reproducibility. This work aimed to conduct a toxicological assessment of feeds with different levels of heavy metals using the luminescent microorganisms Photobacterium phosphoreum. Under the study of heavy metals, corn grits, which did not possess toxic properties, were used as a “matrix.” Heavy metals were used in the form of State standard samples: Arsenic, Cadmium, Lead, Mercury, Copper, and Zinc. Before adding heavy metals to the feed, the “matrix” was previously examined for their content (background). Toxicants were added to the “matrix” in different concentrations, taking into account the “background” indicators (5 series each), which were prepared by diluting in distilled water, depending on the maximum residue limits (MRL). As a result of the work, the possibility of using luminescent microorganisms Photobacterium phosphoreum (strain IMV B-7071; Sq3) was established for rapid toxicological evaluation of feeds with different levels of heavy metals based on the decrease in the intensity of the glow. However, if for Cd, Hg, Zn, Cu under the conditions of the study of feed with the content of heavy metals at the MRL (0.4; 0.1; 25.0 and 120.0 mg/kg, respectively), the feed was characterized as “non-toxic,” then for Pb and As according to the MRL (5.0 and 0.5 mg/kg, respectively), the feed was characterized as “toxic,” which indicates the need for further studies on the toxicological characteristics of heavy metals in the body of laboratory and productive animals, possibly with a further revision (downward) of the MRL of the relevant pollutants in feed in Ukraine.
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