The capability of plant-bacteria consortia to reduce the genotoxicity of unsymmetrical dimethylhydrazine in the environment

Unsymmetrical dimethylhydrazine (UDMH) despite its proven high toxicity continues to be used in rocket technology and some other areas of human activity. In this work, the ability of plant-bacteria consortia to reduce the genotoxicity of UDMH incomplete oxidation products was investigated. Genotoxicity was assessed using a specific lux-biosensor Escherichia coli MG1655 pAlkA-lux sensitive to DNA alkylation in cell. For microbiological biodegradation, the Bacillus subtilis KK1112 strain was obtained by the isolation from soil with a subsequent selection for resistance to high UDMH concentrations (more than 5000 MAC). Its ability to biodegrade UDMH was shown by observing the reduction of DNA alkylation of the KK1112-treated UDMH. The ability of KK1112 cells to act in a bacterial-plant consortium with following fodder halo-phytes was studied: Bromus inermis Leyss, Medicago varia Mart. and Phleum pratense L. A synergistic reduction in the alkylating properties of UDMH oxidation products was observed under the combined use of bacteria and plant seedlings. The greatest effect was obtained when bacteria was used in combination with B. inermis. It was shown that KK1112 cells accelerate the seedlings development and mitigate the growth inhibition that occurs during incubation with UDMH. The obtained results indicate that it is optimal to introduce the bacterium KK1112 in combination with B. inermis plants for soils in arid climate zones during reclamation after UDMH exposure.