The dissertation work was carried out in the laboratory of toxicological monitoring of the NSC "IECVM", in accordance with the tasks: 38.02.02.02 P "Development of new methods for determining the main abiotic toxicants (pesticides, inorganic elements, etc.) to obtain high-quality and safe livestock products" (state registration number 0119U100990) and 34.03.00.01 F "Investigation of the impact of environmental factors on the animal body (nanoparticles, heavy metals, mycotoxins, etc.) and development of a modern system for ensuring the quality and safety of agricultural products by the main control markers" (state registration number 0121U108350).
The scientific novelty of the results obtained is that for the first time in Ukraine, a "Method for determining the total toxicity of feed using photobacteria Photobacterium phosphoreum" was developed (patent of Ukraine for utility model No. 147856) and the system for cultivating this type of bacteria was improved by developing a "Nutrient medium for the cultivation of photoluminescent microorganisms Photobacterium phosphoreum" (patent of Ukraine for utility model No. 143070). For the first time in Ukraine, the dependence of the luminescence intensity of Ph. рhosphoreum on the content of such contaminants as mycotoxins, heavy metals, pesticides and trace elements in feed was studied.
The practical significance of the results obtained is that, based on the study of the intensity of luminescence of Ph. рhosphoreum under the influence of various toxicants, scientific and methodological recommendations "Express methodology for determining the total toxicity of feed using photoluminescent microorganisms Ph. рhosphoreum" were developed (approved by the Scientific and Methodological Council of the State Service of Ukraine for Food Safety and Consumer Protection: Protocol No. 1 of May 12, 2021). The express method for determining the total toxicity allows to provide a quick (1-1.5) hour and highly reliable toxicological assessment of feed. A nutrient medium for the cultivation of photoluminescent microorganisms Photobacterium phosphoreum has been developed, which, due to the introduction of new components, provides a sufficiently high level of bacterial luminescence, accelerates their growth and accumulation of bacterial mass, and is more cost-effective.
Main results of the work. A rapid method for determining the total toxicity of feeds using the bioluminescent microorganisms Ph. phosphoreum has been developed. The methodology is based on determining changes in the luminescence of Ph. phosphoreum photobacteria under the influence of toxic substances present in feeds compared to the control.
The method's validation characteristics were determined. It is specific, accurate, linear, and reproducible. The limit of detection for zearalenone mycotoxin is 0.125 μg/cm3, and the limit of detection for feed is 0.25 mg/kg.
The effect of different levels of pesticides, herbicides, mycotoxins and trace elements on the intensity of Ph. phosphoreum luminescence was investigated and a toxicological assessment of feeds was given by the percentage of decrease in luminescence intensity.
All pesticides dose-dependently inhibited the luminescence of Ph. Рhosphoreum. This allowed to evaluate feeds with a content of HC 0.0025-0.01 mg/kg, α-isomer HCH up to 0.002 mg/kg, β-isomer HCH up to 0.001 mg/kg, γ-isomer HCH less than 0.05-0.2 mg/kg as non-toxic; with HC content 0.05-2.0 mg/kg, DDT 0.01-0.05 mg/kg, α-isomer HCH 0.02-0.2 mg/kg, β-isomer HCH 0.01 mg/kg, γ-isomer HCH 1.0 mg/kg - as toxic and with DDT 0, 1-1.0 mg/kg, α-isomer and γ-isomer of HCH from 2.0 mg/kg, β-isomer of HCH 0.1-1.0 mg/kg - as highly toxic feed.
Feed with the content of Greenfort Premium 0.025 mg/kg, Skat 0.04-0.08 mg/kg, Agroshield Super from 1.0 mg/kg, Greenfort Extra from 0.1 mg/kg, Astanes 0.015 mg/kg, Greenfort NK 40 from 0.2 mg/kg as toxic, and with the content of Soteira 0.01-0, 25 mg/kg, Greenfort Premium 0.05-0.25 mg/kg, Greenfort Horse 0.08-0.2 mg/kg, Skat from 0.2 mg/kg, Agroshield Super from 2.5 mg/kg, Greenfort Extra from 0.2 mg/kg, Astanes from 0.03 mg/kg, Astralid 4.0 mg/kg and above, fungicide Carbendazole from 0.01 mg/kg inclusive as highly toxic, insecticide Veless less than 0.004-0.02 mg/kg and Vyrii less than 0.004-0.01 mg/kg of feed as non-toxic, and with the content of 0.04-0.1 mg/kg and 0.02-0.1 mg/kg, respectively, as toxic.
Feeds with a content of mycotoxin T2 of less than 0.01-0.1 mg/kg, deoxynivalenol of less than 0.5-1,0 mg/kg, ochratoxin A of less than 0.5 mg/kg, fumonisin 5.0-10.0 mg/kg, aflatoxin B1 0, 01 mg/kg - as toxic and at the content of zearalenone 1.0-10.0 mg/kg - toxic feed.Feeds with the content of arsenic less than 0.5-5,0 mg/kg, cadmium less than 2.0-4.0 mg/kg, plumbum from 5.0-50.0 mg/kg inclusive, mercury from from 125.0-250.0 mg/kg as toxic feed.
