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The paper provides a review of the current state of research in the field of biotesting, and the problems of environmental studies and ways to solve them are discussed. The basic principles and examples of using enzymes for detecting toxicants in various environmental samples are considered. Based on an analysis of numerous published data, the advantages and limitations, as well as the prospects for using enzymes for performing biotesting tasks, are assessed. A separate section of the review is devoted to bioluminescent enzymatic bioassays developed by the authors and successfully used for environmental monitoring of water, soil, and air. The necessity of developing a battery of enzymatic bioassays is substantiated. It allows one to have the most complete and accurate information about the degree of pollution of environmental objects.

The effects of viscous media with glycerol and sucrose (10–40%) on the kinetics of the bacterial bioluminescent reaction have been investigated by stopped-flow technique. Increment of quantum yield in media with 10% of both osmolytes was shown. Higher concentrations of glycerol, up to 30–40%, were found to reduce the efficiency of the reaction, while this effect was not observed in the media with sucrose. The molecular dynamics simulation was used to study the structure of bacterial luciferase surrounded by either water molecules solely or by mixture of water with various numbers of glycerol/sucrose molecules. It was found that both cosolvents at studied concentrations did not cause a significant change in conformation of bacterial luciferase. The calculated root-mean-square fluctuation for Cα-atoms of bacterial luciferase α-subunit indicated that the higher flexibility of the enzyme mobile loop could be responsible for increment of quantum yield in the presence of 10% of both osmolytes. The active site of bacterial luciferase was found to be accessible for glycerol molecules while sucrose did not enter catalytic gorge. Moreover, at 30 and 40% concentration the glycerol molecules were found to locate in the active site of bacterial luciferase throughout the whole simulation time.

A concept of the comprehensive assessment of soil contamination is proposed. According to it, the conclusion regarding the presence of toxic substances in the analyzed sample is based on the inhibition of enzymatic reactions responsible for various functions of a living organism, such as luminescence, respiration, etc. These functions are taken as test functions in classical bioassays with the use of living objects (luminous bacteria, daphnia, algae, and others). The regularities of the impact of different classes of toxicants on the activity of particular enzymes or coupled oligo-enzyme chains have been established. These enzyme reactions are selected as potential test objects: markers of contamination. Three enzyme systems with the maximal sensitivity to different classes of toxicants have been chosen for the set of enzymatic bioassays: butyrylcholinesterase, NAD(P)H:FMN-oxidoreductase + luciferase, and lactate dehydrogenase + NAD(P)H:FMN-oxidoreductase + luciferase. The possibility to use enzymes instead of living organisms in the bioassay of natural complex systems has been shown.

In this study, we formulated the principles of designing bioluminescent enzyme tests for assessing the quality of complex media, which consist in providing the maximum sensitivity to potentially toxic chemicals at a minimal impact of uncontaminated complex media. The developed principles served as a basis for designing a new bioluminescent method for an integrated rapid assessment of chemical safety of fruits and vegetables, which is based on using the luminous bacteria enzymes (NAD(P)H:FMN oxidoreductase and luciferase) as a test system.

The functioning of NAD(P)H:FMN‑oxidoreductase (Red) from Vibrio fischeri under conditions of macromolecular crowding (MMC) simulated in vitro by adding biopolymers (starch and gelatin) was studied. The dissociation rate constants and the activation energies of dissociation of Red to the subunits were calculated, and the process of denaturation of Red was analyzed. It is shown that the functioning of Red both under conditions of MMC and in diluted solutions is the same. This result refutes the common belief that the native conformation of enzymes in vivo is stabilized due to MMC as compared to the in vitro conditions.

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала. This study assesses the comparative sensitivity and possibility of obtaining fast results of various methods of biotesting for several surfactants: Tween 85, sodium dodecyl sulfate (SDS), Fairy dishwashing gel, and Mif washing powder. The following test organisms are used for the study: luminescent bacteria Photobacterium phosphoreum (Beijerinck), preparation of Ecolum luminescent bacteria, unicellular algae Scenedesmus quadricauda (G.M. Smith), infusorian Paramecium caudatum (Ehrenberg), and crustacean Daphnia magna (Straus). It has been revealed that Fairy dishwashing gel possesses the strongest toxicity against the studied test objects. Daphnia and algae are most sensitive to the effects of Fairy and SDS, protozoan and luminescent bacteria are most sensitive to SDS, and Ecolum is most sensitive to Mif washing powder. The tested aquatic organisms and Ecolum are most tolerant to the effect of Tween 85.

A new method for obtaining stable butyrylcholinesterase (BuChE) samples based on the enzyme immobilization in starch and gelatin gels followed by drying is proposed. Coimmobilization of BuChE with the thiol group indicator 5,5'-dithiobis(2-nitrobenzoic) acid did not reduce the activity of BuChE, which allowed us to simplify the procedure and reduce the time of analysis of organophosphorus pesticides. The resulting immobilized samples retained activity for at least 300 days. BuChE samples based on the starch gel showed a greater sensitivity in the determination of pesticides as compared to the samples based on the gelatin gel.