Background: The bacterial destructing activity toward pesticides has been the focus of research in the last few decades. Hexachlorobenzene is included in the organochlorine pesticides group that are prohibited for use. However, large hexachlorobenzene amounts are still concentrated in the soil, stressing the relevance of research on hexachlorobenzene-destroying bacteria. Methods: The ability to destroy hexachlorobenzene by Comamonas testosteroni UCM B-400, B-401, B-213 strains was investigated and established. Bacteria were cultivated (7 days at 28 °C) in mineral Luria-Bertrani (LB) medium with three hexachlorobenzene doses: 10, 20, 50 mg/L. The hexachlorobenzene concentrations were recorded by a gas chromatography method. Results: The results showed that C. testosteroni UCM B-400, B-401 have high destructive activity toward hexachlorobenzene. The highest (50 mg/L) initial concentration decreased to 41.5 and 43.8%, respectively, for C. testosteroni UCM B-400, B-401. The unadapted C. testosteroni UCM B-213 was tolerant to hexachlorobenzene (cell titers after cultivating with 10.0, 20.0, 50.0 mg/mL were higher compared to initial titer), but had a low-destructing activity level (two times less than B-400 and B-401). Conclusions: Bacterial strains C. testosteroni UCM B-400, B-401 can be seen as a potential soil bioremediation from hexachlorobenzene pollution.

Aim. Given the prospects of the method of detoxification of organochlorine contaminants in environment using microorganisms, the aim of the work was the investigation of the effect of microbial destruction products of pesticide hexachlorocyclohexane (HCCH) on morphogenetic and morphophysiological reactions of tomato in vitro. Methods. To test the effects of HCCH and its microbial degradation products obtained by strains of Bacillus megaterium, Pseudomonas putide 3, Stenotrophomonas maltophilia 6, these compounds were added to nutrient medium for tomato cultivation. As explants the segments of hypocotyls of L. esculentum seedlings were used. For plant regeneration, MS medium supplemented with 1 mg/l of zeatin and 1 mg/l IAA was used. Results. It was found that the products of HCCH destruction stimulate the shoot regeneration, but inhibit their rooting, whereas HCCH inhibits the shoot formation and provokes further morphophysiological changes in plants. Conclusions. A pronounced negative effect of pesticide HCCH on cells and tissues of tomato in vitro was revealed. It was found that the products of HCCH destruction do not affect the morphogenetic processes of isolated tomato cells and tissues and do not cause morphophysiological changes in obtained in vitro tomato plants.